7299721 Kt San Xuat Chat Deo

8/9/2019 7299721 Kt San Xuat Chat Deo

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BI GING MN K THUT SN XUT CHT DOGV SON: PHAN TH ANH


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PHN 1CNG NGH SN XUT MT S POLYMER TRNG HP

CH NGI: SN XUT POLYETYLEN (PE)

I.Nguyn liuNguyn liu sn xut PE l etylen (C2H4), ch yu thu c t vic cracking du m.

Tnh cht ca C2H4:+ tonc = -169oC+ tos = -103,8oC+ Khi lng ring tosi: d(ts) = 0,57 g/cm

3

Etylen khng phn cc ( o =0) nn kh trng hp. Lng nhit to ra khi trng hp cao.

Monome Lng nhit to ra (cal/g)

C2H4 (kh) 800

Stryren (lng) 164

MMA (nh tng) 129

Etylen dng sn xut yu cu :

C2H4 98%

C2H6 12%

N2 0,51%

C2H2 0,10,3%

II.L thuyt trng hpPhn ng trng hp etylen thnh PE c th thc hin theo cch gc hoc ion.

1.Trng hp gcPeroxit, pesulfat, hp cht azo v cc dn xut alkyl ca cc kim loi khi un nng

to ra gc t do. Cc gc t do mi ny d dng phn ng vi etylen:

R + CH2=CH2 R-CH2-CH2

Gc ny tip tc pht trin :

R-CH2-CH2

+ nCH2=CH2 R-(CH2-CH2-)CH2-CH2

Giai on ny nhit phn ng to ra rt ln do cn phi ly nhit ra khi hn hp

phn ng. Nu khng do s tng cao nhit etylen khng phn ng b phn hu vthng km theo ting n.Phn ng pht trin mch ngng l do kt qu kh hot tnh gc polymer

R-(CH2-CH2-)nCH2-CH2

+ CH2=CH2 R-(CH2-CH2-)nCH=CH2 + CH3-CH2


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Trong qu trnh phn ng, do s kt hp ca cc phn t etylen hoc gia monomevi i phn t polymer to ra nhnh.

R-(CH2-CH2-)m

CH-CH2-CH2-CH3 + nCH2=CH2

nCH2=CH2 + CH2=CH2 + mCH2=CH2

2.Trng hp ionng ch l trng hp etylen theo cch trng hp ion c xc tc Xigle-Naptha,TiCl3 + Al(R1)3 R1: C2H5

TiCl3 + Al(R1)3 0t

+

TiCl2Cl

Al(R1)3 ++

CH2=

CH2 0t

+u im:Trng hp etylen c xc tc Xigle-Naptha c nhiu u im nh polymer t nhnh,

tnh cl cao.+Nhc im:

R-(CH2-CH2-)mCH-CH2-CH2-CH3

(CH2-CH2)n-1-CH2-

CH2

-(CH2-CH2-)nCH-(CH2-CH2-)m

CH3

TiCl2Cl

Al(R1)3+

CH -

CH2


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Xc tc t, d chy nSau khi kt thc qu trnh phi tch xc tc ra khi polymer phc tp.

III.Cc phng php sn xut PENha Polyetylen c nhiu loi: HDPE, LDPE, LLDPE, VLDPE, nhng trong th

trng ph bin l 2 loi HDPE v LDPE.

HDPE l PE c khi lng ring ln. C th sn xut theo 2 phng php:+p sut trung bnh (3040 atm)+p sut thp (34 atm)

LDPE l PE c khi lng ring b. Sn xut theo phng php p sut cao(15002500 atm).

1.Phng php p sut cao (P=15002500 atm)Phng php trng h p etylen trong pha kh p sut cao v nhit cao

(180200oC) c cht khi u l O2 l phng php cbn sn xut PE c t trngthp, trng lng phn t10.00045.000.-Cc yu tnh hng n qu trnh trng hp:

+Hm lng O2 trong kh

Oxi l cht khi u trng hp, tc phn ng ph thuc vo lng O2 trong kh,nhng v nhit v p sut cng nh hng nhiu n n nn s ph thuc ny rt phctp.

Nu nng O2 qu cao, etylen s b phn hu thnh C, H v CH4.VD: 2000 at v 165oC phn hu xy ra ngay 0,075% O2 so vi lng monome.Trong 2 th trn ta thy tt c cc nhit v p sut u c hiu sut cc i v

hng v pha O2 t.+Nhit :

Tng nhit phn ng n gi tr nht nh s lm tng nhanh qu trnh trnghp v tng hiu sut polymer, trng lng phn t gim.

0,01 0,02 0,03 0,04

170 C160 C

150 C

oo

o

1350 atm

0,040,030,020,01

1150 atm

1000 atm

100 atm5

10

15

Hiu sut (%)

% Oxi % Oxi

15

10

5

Hiu sut (%)


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Tng nhit phn ng ph cng tng theo.+p sut:

p sut tng th vn tc phn ng v hiu sut to thnh polymer ln.

nh hng p sut n vn tc trng hp-Thit b phn ng loi ng c dng dtng=1030mm-c im ca loi trng hp cao p:

+C lin kt i cui mch nhiu (do chuyn mch, t mch)+C nhnh CH3, (-C2H5) ln hn cc phng php khc hm lng tinh th

khng cao.

K-(CH2-CH2-)x CH2-

CH2 + CH2=CH2 K-(CH2-CH2-)x CH2-CH2-

CH-CH3

K-(CH2-CH2-)x

CH- CH2 + CH2=CH2

-u, khuyt im:+u im:

Sn phm sch (v khng dng cht khi u hu c), tnh cch in cao.+Khuyt im:

V p sut cao: kch thc thit b b nn nng sut b.

Nng lng tiu hao nhiu do qu trnh nn kh.Thit bt, lm t thp c bit, vn lm kn thit b, vn chuyn etylen p sut

cao c nhiu kh khn. phng php cao p t sn xut.

2.Phng php sn xut trung bnh (3040 atm)Trng h p etylen trn xc tc oxit crom c th tin hnh theo phng php gin

on v lin tc trong dung mi hoc trong pha kh trng hp cation.

1000

2000

3000

300 1100 1500 2500

Vp khi p= 1atm

p (atm)

V5000

4000

K (CH2

CH2)x CH CH

2

CH2

CH2


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-Cc giai on chnh ca qu trnh:+Chun b xc tc: Trn CrO3 vi cht mang alumino silicat. Yu cu ca xc tc l

phi c th tch t do v b mt ca mao qun phi ln Vtd= 1cm3/g

F = 400500m2/gXc tc s dng dng huyn ph l 0,2-0,6%.

+Chn dung mi: Dung mi ch ho tan C2H4 v khng ho tan polymer, rumetylic, xiclohecxan, xng tinh khitCH3OH l dung mi tt nhit no cngkhng ho tan polymer nhng ho tan monome.

+Tch xc tc ra khi hn hp sn phm: Mun tch xc tc th phi ho tan PEtrong dung mi thch hp ri tch xc tc bng my li tm. Sau sy tch dung mi tac PE em i to ht.

-Cc yu tnh hng :

p40302010

1,8

0,6

110

10

10 20 30 40 p

[] Lng PE (g/g xc tc)

t(pht)2015105

15

10

5

115-120 C125-130 C

100-105 C

135-140 C

135-140 C

PE (g/g xc tc)o

oo

o

o

0,6

1,8

50 10 15

[]

t po


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p sut cng ln th [] cng ln PM cng cao

Nhit phn ng cng ln [] cng gim PM cng gim.

p sut cng tng, hiu sut to PE cng ln.Nhit thp th hiu sut phn ng thp, nhit cao th hiu sut cao nhng khi

tng nhit ln na (125130oC) th hiu sut gim v khi nhit (135140oC) thhiu sut rt thp.

Khi nhit cng cao th xy ra nhiu phn ng ph nh: ngt mch, oxi ho,.. nnhiu sut gim.-u, nhc im:So vi phng php p sut cao:

+u im:-Khng dng cc thit bt tin

-Th tch thit b ln nng sut cao gi thnh h.-% tinh th ln (>85%) do t phn nhnh-Khi lng ring d ln hn PEHD

So vi phng php p sut thp:

+u im:-Xc tc r, an ton khi s dng (t c, khng gy chy n)-D ti sinh dung mi.

+Nhc im:-V xc tc l cht rn (CrO3) nn tch xc tc kh khn, mun tch phi ho tan PE

ri lc, sau sy tch dung mi phc tp.

3.Phng php p sut thp (3-4 atm)Trng hp etylen trong dung mi c th thc hin c vi cc loi xc tc v cc

cht khi u khc nhau, ph thuc vo h thng khi u m cc iu kin trng hp vtnh cht ca polymer thu c s thay i.

Dung mi s dng c th ho tan hoc khng ho tan polymer, thng dng: rumetylic, xiclohecxan, n-hecxan, n-heptan, benzen,.. trong ru metylic l dung mi tt trng hp etylen v n ho tan etylen m khng ho tan PE.

Xc tc c s dng rng ri trng h p etylen l Xigle-Naptha(TiCl4+Al(C2H5)3)Qu trnh tin hnh:

Cho dung mi bezin + xc tc to thnh hn hp huyn ph, cho monome etylen p sut 3-4atm vo thit b phn ng. Nng nhit t t ln 75-80oC, gito=80oC n khi

kt thc phn ng, hiu sut 9295% . nhit ny PE khng ho tan trong benzin,khi t hiu sut ngi ta tch PE ra khi huyn ph bng li tm. Sau ra sch bng


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CH3OH ( tch cc xc tc cn ln li) ri ra li bng nc. Sau PE c sy khvi hm m W=0,250,5%, c to ht, ng bao.

Benzin c cha polyetylen t trng thp v hn hp benzin, rc c em i chngtch, lm sch, s dng li.u, nhc im:

+u im:-Tin hnh p sut thp nn nng lng tiu hao b nht nng xut sn xut ln

gi thnh thp.-Trng lng phn t ca PE ln nn bn chc, bn nhit cao hn phng php

p sut cao.+Nhc im:

-Phi hon nguyn dung mi nn dy chuyn sn xut phc tp tn km.-PhI tch ht xc tc ra khi PE ra-Xc tc d chy n khi tip xc vi khng kh

IV.Cu to, tnh cht v ng dng ca PE1.Cu to

Phn t polyetylen c cu to mch thng di gm nhng nhm etylen, ngoi ra cnc nhng mch nhnh. PE l polymer khng phn cc, monome lng cc 00 .

Nu mch nhnh cng nhiu v cng di th kt tinh cng km. PE c kt tinhtng i cao v khc nhau i vi mi loi. Trong PE phn tinh th lm cho mch cngnn bn nhit , bn vi tc dng chc, cn phn v nh hnh lm cho mch mm.

Cu to ca PE ph thuc vo phng php sn xut.

HDPE LDPE

S lng nhm -CH3 (nhnh) trong 1000 nguyn t C

LoiTng lng

nhnh

cui mchNhnh

CH3

Nhnh C2H5

PE cao p 21,5 4,6 2,5 14,4

PE p sut th p 3,0 2,0 - 1

PE p sut trung bnh 2,5 1,5 - 1

Ta thy hai phng php sau nhnh t do c siu chnh bi xc tc.


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Lng nhm khng no tnh trn 1000 nguyn t C;

Loi PE Tng lngni i

PE p sut trung

bnh 1,11,3 87% 7% 6%PE p sut th p 0,40,5 52% 31% 17%

PE p sut cao 0,30,4 17% 71% 12%

2.Tnh cht ca PEn gin y ta nu ra mt s tnh cht quan trng ca 2 loi PE thng dng l

HDPE v LDPE.

HDPE+T trng d= 0,950,96

+Khng ht m, mc hp th nc trong24h


10/79

+Tnh bm dnh km, d chy, khng mi, khng v, khng c* ng dng ca PE:

Ta ch quan tm n 2 loi nha PE thng l HDPE v LDPEHDPE+Sn xut loi mng (ti xp, ti ng ho cht, thc phm,..)

sn xut mng , ch s chy (MI)


11/79

CHNG II: SN XUT POLYPROPYLEN (PP)I.Nguyn liu

Nguyn liu sn xut PP l propylen, c tch t kh cracking du m hoc tsn phm du m. Khng chiu kin cracking (to, p, t, cht xc tc,) ta c th thuc propylen v etylen. Dng phng php lm lnh tch v lm sch propylen.

Tnh cht ca propylen:

CTCT: C3H6

2CH =+

CH CH3Propylen l cht kh c ts= -47,7

oC v tnc= -185,2oC. nhit si, t trng ca n0,610g/cm3

Do nh hng ca nhm CH3 nn phn t Propylen c s phn cc, momen lngcc 0,35 debai.

II.L thuyt trng hp propyleniu ch PP trng lng phn t cao tin hnh trong iu kin c xc tc d th. Cu

to b mt kt tinh ca cht xc tc c vai tr quan trng trong vic iu ch phn tpolymer c cu trc khng gian u n.

Ngi ta cho rng, trc ht cc phn t monome b hp th ln b mt cht xc tcv nh hng, sau dnh vi mch ca polymer nhm ni i. Kt qu thu c

polymer kt tinh c cu to thng, u n.Bng cch thay i h thng xc tc, c th loi tr tc dng khng gian ca cht

xc tc v thu c polymer v nh hnh, c th thay i t l gia polymer c cu trcu n. Xc tc dng huyn ph cho polymer c cu trc khng u n.Cch:


12/79

Tu thuc vo iu kin trng hp, loi xc tc khc nhau m ta thu c polymerc cu trc khc nhau iu ho hay khng iu ho.V d: + PP c cu to khng gian khng cao c th thc hin trong h xc tc: dungdch TiCl4 + Al(C2H5)3nhit 35 80

oC, p = 3 5atm.+ PP c cu to khng gian cao th dng h xc tc: TiCl4 nghin mn + dung

dch dietylalumin clorit nhit 70 - 80oC, p = 5atm.+ Hoc dng dung mi n-heptan, cc cacbuahydro khc c nhit si thp hn

nhit nng chy ca polymer kt tinh n 50 80oC tch PP c kt tinh cao rakhi PP v nh hnh v PP c kt tinh thp.

Nhit thp vn tc phn ng gim, thi gian phn ng tng, hiu sut gim, hmlng izotactic v trng lng phn t trung bnh tng.

Nhit cao th ngc li v hu ht to ra atactic.

3. Cc phng php sn xut PP.3.1. Phng php c

p sut lm vic ca thit b phn ng l 4 6atm v nhit 50 55oC.Cho dung mi (benzin) v lng xc tc cn thit (TiCl3 + Al(C2H5)3) vo thit b

phn ng. Sau cho propylen lc sch O2 vo, duy tr nhit 50 55oC cho n

khi hiu sut t 95%, em lm lnh n 10oC tch PP dng huyn ph bng phngphp ly tm ri em x l xc tc bng CH3OH trong dung dch HCl. Ra PP bng ncv sy trong iu kin chn khng nhit 60 - 70oC n m 0,25 0,5% ri em ito ht.3.2. Phng php mi ( do Naphta ra)

Dng hn hp propan (C3H8) propylen (C3H6) vi t l theo khi lng 30/70. Hxc tc l TiCl3 + Al(C2H5)3 p sut phn ng 6 - 8atm v nhit phn ng 50 55

oC.u tin C3H8 ho tan C3H6ng vai tr nh l dung mi ca phn ng. Khi trng

hp xong a v p sut thng hoc thp, C3H8 khng ho tan c PP c ho hi thu hi. Mt t C3H8 hp th vo PP ta dng hi nc qu nhit ko ra. Sau ra tchxc tc bng CH3OH trong dung dch HCl, ra li bng nc, sy chn khng v to ht.3.3. Trong cng nghip

Cho propylen vo trng hp trong ni phn ng p sut n 100atm v khuy u.Cht xc tc phn tn trong cacbuahydro lng. Duy tr nhit phn ng thp hn nhiuso vi nhit chy mm ca polymer. Sau khi c 40% hn h p phn ng chuynthnh polymer th chuyn dung dch huyn ph cha: dung mi, polymer v cht xc tcvo thit b bc hi tch ( p sut thp ) propylen khng phn ng v hon nguynn v sn xut. Sau nhmy ly tm hoc my lc tch polymer dng bt v dung mira. Ra polymer bng CH3OH trong dung dch HCl long. Giai on ny phc tp i hi


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thi gian khuy trn nhiu, sau mi ln ra phi dng my lc ly tm, dng nhiu ru vtiu hao nhiu dung mi.

IV.Cu to, tnh cht v ng dng ca PP1.Cu to

Phn ln l isotactic, mt phn nh l syndiotactic v atactic. Khi nhit phn ng

t=50oC v dng xc tc TiCl3-Al(C2H5)3 th hm lng isotactic: 8595% hm lng kttinh ln.

V mi mc xch c mt nhm CH3 nn mch cng hn PE v th bn c, bnnhit ln hn PE.

Cng thc cu to:

Ta thy cng thc ca PP c nguyn t H C bc 3 rt linh ng do PP d b oxiha, lo ha.2.Tnh chtTnh cht l nhit ( bn nhit)

+Nhit nng chy cao tnc= 160170oC

+n nh 150oC khi khng c ngoi lc+Chu c nc si lu, khng b bin dng.+ 155oC, PP vn cn th rn, nhng n gn nhit nng chy PP chuyn sang

trng thi mm cao (nh cao su).+Khi gim t nhit nng chy n 120oC, PP bt u kt tinh nhit kt tinh

cao

15010050

150

50

0

100

1 2 3

4

5

dn di ca cc vt liu khc nhau nhit cao

1 PE t trng thp2 Polymetylmetaacrylat3 PE t trng cao

-(CH2-CH-)n

CH3

dn di tng i (%)

Nhit (oC)


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4 PVC5 PP

+Cc tp cht v khi tip xc vi cc kim loi nh: Cu, Mn hoc cc hp kim chakim loi , c nh hng ln n tnh chu nhit ca vt liu. Do phi ht sc trnh.

Kh nng chu nh sng mt tri:

Do c nguyn t H C bc 3 linh ng nn d b oxi ho, lo ho.+PP khng c cht n nh

-Di nh sng khuyt tn vn n nh tnh cht trong 2 nm.-C nh sng trc tip th ch sau vi thng s b gin v ph hu ngay.

+PP c cht n nh (hoc dng mui than 2%) di nh sng trc tip (tia cc tm)th sau 2 nm tnh cht khng thay i, bn trong 20 nm.

bn ho hc

+ nhit thng, PP khng tan trong cc dung mi hu c, ngay c khi tip xclu, m ch trng trong cc cacbuahydro thm v clo ho. Nhng nhit trn 80oCth PP bt u tan trong hai loi dung mi trn.

+Polymer c kt tinh ln bn ho cht hn polymer c kt tinh b.+PP thc t xem nh khng ht nc, mc ht m


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Loi trong: nhiu pha v nh hnhdng cho bao b y t, bao b thc phm, xylanhtim, CD, VCD, sn phm loI c bit trong cho thc phm , khng mi, c bng bmt cao.


16/79

CHNG III: SN XUT POLYSTYREN (PS)I/ Nguyn liu

-Nguyn liu sn xut PS l Styren c cng thc phn t C8H8 v cng thc cu toCH=CH2

-Cc tnh cht vt l ca Styren: Styren l mt cht lng trong sut, khng mu nhi vng c mi hc, khc x nh sng mnh.

- Khi lng ring 25oC : d= 0,9045 (g/cm3)

- nht (25oC) = 0,7 cp- Nhit si: ts = 145,2

oC- Nhit nng chy: tnc = -30,63

oC- Nht bng chy: tbc = 34

oC

- Nhit ho hi: 86,9 (kcal/mol)- Nhit trng hp: 16,5 (kcal/mol)- Gii hn chy n trong khng kh (%V): 1,1 6,1- co th tch khi trng hp: 17%

Styren tan trong cc dung mi khng phn cc hay phn cc yu: xtn, CS2, este,hydrocacbon mch h, vng no hp cht thm v dn xut halogel. Styren t tan trongnc v trong cc glycol khc.

Styren c, gy kch thch nim mc mt, mi, phi, gy ngc thn kinh. Vinng 0,2 mg/ lit c th lm h da, nim mc mt v c hng.

-Tnh cht ho hc ca Styren:+ Cng hydr:

CH=CH2 CH-CH3H2, Ni25oC, 3at

+ Cng halogen:C6H5-CH=CH2 + Br2 C6H5-CHBr-CH2Br

+ Cng HA ( HOH, HX, H2SO4...)C

6H

5-CH=CH

2+ HA C

6H

5-CH-CH

3

A+ Phn ng oxy ho:

C6H5-CH=CH2 + O2 C6H5-COOH + CO2 + H2OStyren rt d trng hp v c ni i v vng thm, trong qu trnh bo qun nn

hn ch cho tip xc vi nh sng, oxy, nhit . Thng thng khi bo qun ta cho 0,5 1,5 % khi lng hydroquinon vo lm cht c ch trng hp.


17/79

-iu ch Styren: Styren c th thu c t hai ngun:+ T sn phm Cracking v chng ct du m, kh ho than cc.+ Bng con ng tng hp:

C2H6 + C2H4 C6H5-CH2-CH3

C6H5-CH2-CH3 C6H5-CH=CH2 + H2

II/ L thuyt trng hp StyrenTrong sn xut Styren ch trng h p theo c ch trng hp gc v thu c

polymer c cu to ch yu l lin kt u - ui v dng v nh hnh. Trong nghincu ngi ta c s dng trng hp ion to PS tinh th hu ht dng izotactic, mt phndng syndiotactic, rt t dng atactic.

Styren d trng hp khi, trng hp dung dch, trng hp nh tng v trng hphuyn ph. Mi phng php u c nhng u, nhc im ca n.1/ Trng hp khi

Trng hp Styren thnh khi c th tin hnh khi un nng c cht khi u hockhng c cht khi u.

Cht khi u thng l cc peroxit hu c. Benzoyl peroxit l cht khi u rtph bin nhng khng thch hp khi trng hp styren v n lm vng sn phm.

Tc trng hp tng theo nhit nhit di 50oC vn tc trng hp rtchm (c khi n hng nm), 150oC phn ng kt thc trong vi gi. Nhng khi chuyn

ha c khong 90% th phn ng chm li v khi c 9899% th phn ng hu nhkhng xy ra na. iu c ngha l polymer c trng lng phn t cao khng thuc vi hiu xut cao. Nu cn li nhiu monome th nhit chy mn ca PS s gimxung, vt phm trnn c do monome chuyn ln b mt v bc hi t ti khi lmvng sn phm.

thu c polymer c trng lng phn t trung bnh cao tng i v chamonome cn li t nht ta dng ch trng hp hai giai on:

+ Giai on u: to ra xirop (PS c trng lng phn t thp tan trong monome)

vi hiu sut 3040%.+ Giai on hai: vo khun ( c th tch nh 510 lt) sau trng hp tip tccho n khi kt thc. Tho sn phm ra khi khun em p, nghin, sng hay to ht.2/ Trng hp dung dch

So vi trng hp khi th phn ng trng hp trong dung dch xy ra vi vn tcb (iu kin khng c cht khi u) v polymer to ra c trng lng phn t thphn. Gi tr trng lng phn t trung bnh ca PS ph thuc vo iu kin trng hp v

90-95oC

AlCl3

dehydro ha

ZnO, 500oC


18/79

loi dung mi. Qua th nghim thy benzen, xiclohexan, toluen trng hp tt hn ccdung mi khc.

iu ch polymer trong dung dch thun li lm sn, cn vi mc ch khc ththm cht lm lng kt ta polymer.3. Trng hp nh tng

Nh tng gm c: monome, nc, cht nh ha, cht khi u v cht iu chnhsc cng b mt.

Cch trng hp nh tng: cht nh ha khi tan trong nc to thnh cc Mixenhnh cu m cc u khng a nc ca phn t nh ha s hng vo trong v ccu a nc hng ra ngoi. Cc phn t cht khi u tan trong nc to thnh cc gct do nh phn a nc ca cht nh ha i vo Mixen v ti p xc vi cc phn tmonome xy ra cc phn ng trng hp.

+ Nc l mi trng phn tn cng l cht ti nhit iu chnh nhit phn ngta ra.

+ Cht nh ha: gi monome v polymer mi trng thi phn tn trong phanc. Cht nh ha thng dng l cc loi x phng nh: lat kali, natri, starat hay ccsunfoaxit ca ru cao bo, x phng nha thng, nkan

Nu gim nng cht nh ha th vn tc phn ng gim, nhng thi gian trnghp v trng lng phn t trung bnh polymer tng. V vy mun iu chnh trng lng

phn t trung bnh polymer trc ht nn thay i nng cht khi u chng thayi lng cht nh ha. V cht nh ha ch thay i M ca PS mt t nhng li tng thigian trng hp ln rt nhiu.

+ Cht kch ng: l cc peroxit v hydroperoxit tan trong nc ( H2O2, pesulfatamn v kali..) vi hm lng 0,11% trng lng monome.

Khi thnm cht xc tin ( cc mui kim loi c tnh axit: ion Ag+ ) lm phn hycht kch ng vo hn hp phn ng th thi gian trng hp gim.

Nu dng h thng oxi ha-kh: cht oxy ha ( cht kch ng ) v cht kh (mui kim loi c ha tr thay i) th vn tc ca qu trnh trng hp c th tng v gimnhit phn ng xung.

+ Cht iu chnh: thng dng ru hay cc cht lm gim sc cng b mt cah thng tc l c kh nng lm tng khuch tn ca nh tng.4/ Trng hp huyn ph

Huyn ph gm: monome, nc, cht kch ng, cht n nh v cht hot ng bmt. y cht kch ng peroxit hu ckhng tan trong nc m tan trong monome.

+ Nc dng tch monome ra thnh tng ht ring ng thi cng l mitrng trao i nhit.


19/79

+ Cht n nh l cc polymer hu ctan trong nc nh ru polyvinilic, metylxenluylochng phi hon ton khng tan trong monome. Vai tr ca n l lm tng nht ca nc v do ngn cn cc ht polymer dnh vo nhau.III/ Sn xut Polystyren (PS)1/ Trng hp khi:

+ Phng php gin onQu trnh gm hai giai on

- Giai on 1: trng hp sb Styren p sut thng sau to chn khng 200-270mmHg v un nng. Khi hiu sut phn ng t khong 30-40% tin hnh lm lnh n70-80oC v rt vo khun c dung tch t 5-10 lt.

- Giai on 2: trng hp xirp trong khun nh nhun nng. Sau tho sn phmra ri em i p, nghin, sng v ng bao.

Cc yu tnh hng n qu trnh trng hp khi:

Nhit trng hp(oC)

Vn tc ban u (%trong 1 gi)

nht (Cp)(d2 10% trong Toluen) P

60 0,089 3.000 2.250.000

80 0,462 650 880.000

100 2,15 200 420.000

140 28,4 30 130.000

160 -- 14 83.000

50oC phn trm chuyn ho rt b, thi gian trng hp rt lu.

150 oC trng hp ch trong vi gi,P

=100.000.

+ Phng php lin tcHnh v ( xem sch )

-Styren t thng lng (1) t chy lin tc vo ni phn ng (3). Trn ng chyc b tr thit b lc (2) tch b cc tp cht chc. Nhit phn ng duy tr ni (3)t 75-80oC, vn tc cnh khuy khong 50-60 vng/pht. Khi hiu sut phn ng t t18-20% ta cho xirp chy vo thp trng hp c chiu cao 7.000 mm, ng knh 650mm. Thit b (4) chia lm 4 khu vc, khu vc I ch c v bc ngoi un nng, cc khu

vc khc c thm ng xon rut g bn trong un nng. Hi bay ra khi thit b phnng (4) c ngng tthit b lm lnh (5). Sn phm PS nng chy t khu vc VI ivo phn hnh nn ca thp c nhit 235oC sau nh trc vt y lin tc ra thnh

bng hay thi, ri em i lm ngui v thc hin qu trnh p, nghin, sng, ng bao.-Ch nhit trong thp phn ng (4):

STT Nhit phn ng (oC)


20/79

Ch 1 Ch 2 Ch 3

I 100-110 100-110 100-110

II 100-110 120 145

III 150 145 165

IV 150 190 220

V 180 200 230VI 180 215 235

2/ Trng hp dung dch- Phng php gin on c 3 giai on: trng h p trong ni phn ng, tch

polymer khi dung dch, p nh polymer.- Phng php lin tc: cho Styren v dung mi t thng lng theo t l nht nh

vo thp trng hp (gm nhiu thp ni tip nhau). Dung dch PS nht t cui thp trnghp chuyn vo thit bun nng nhit lm vic khong 225oC tch dung mi v

mt phn monome khng phn ng. Sau PS dng nng chy cho qua my n trcvt to dng cho sn phm v lm ngui bng nc.3/ Trng hp nh tng

Nguyn liu I II III

Styren 100 100 100

H2O 250 175 200

X phng du thu du (du ve) 3 0,4-1,2 -

K2S2O8 0,25 0,3 -

H2O2 (d2 30%/H2O) - - 2,5

u tin cho nc v x phng du ve vo thit b phn ng tin hnh khuy trn.Sau cho styren v cht khi u vo, duy tr vn tc cnh khuy khong 120-160vng/pht. un nng hn hp ln 65-70oC lc ny cht khi u bt u phn ly v to racc gc t do, phn ng xy ra theo cch trng hp gc, phn ng to nhit nn nhit ca hn hp t tng ln 85-90oC. Ginhit ny cho n khi hm lng monome dtrong hn hp phn ng nh hn hoc bng 1%. Khng nn tng nhit ln na v khi cc ht PS va to ra s chy mm v dnh li vi nhau.

Sau tin hnh ph nh tng ri em i lng, lc, ly tm tch polymer ht b

v dung dch cht nh ho, cht khi u cn d...Monome t do c thc tch bngcch sc hi nc qu nhit vo hn hp polystyren nc thc hin qu trnh li cunhi nc.

Vic ph nh tng c th thc hin bng nhiu cch khc nhau chng hn nh:- Dng nhit ph h nh tng- Dng chc: khuy mnh vi vn tc khuy 3.000-6.000 vng/pht.- Dng in trng


21/79

- Dng cht in ly: mui n, NH4Cl, ZnCl2, CH3COOH...Sn phm to ra em ra nhiu ln bng H2O lm sch ht cc cht nh ho cn

li trn b mt cho n khi trung tnh. Cui cng em i sy kh n m nh hn 0,5% v sng phn loi, ng bao.4/ Trng hp huyn ph

Cho nc, monome v cht khi u t t vo thit b phn ng ng thi mcnh khuy chy vi vn tc 80-120 vng/pht. Cho tip dung dch PVA vo. Ban unng nhit ln 75-80oC trong vng 1,5h sau tng nhit ln 88-90oC trong vng2h. Tng thi gian phn ng khong 4-5h, hiu sut t 95-98%.

Hn hp huyn ph gm: ht PS, mi trng em ly tm v ra bng nc m 45-50oC sau em i sy kh nhit 65-75oC trong chn khng n m nh hn0,2-0,5%.

IV/ Cu to, tnh cht, ng dng ca PS1/ Cu to

Qua nhiu phng php nghin cu khc nhau, c bit l phng php nhit phnPS th thy rng PS c cu to u ni ui

CH2 CH CH2 CH CH2 CH

PS nhit phn ng khng cao th t to nhnh v nhnh b.

2/ Tnh chtPS l cht do trong sut , cng chc, khng mi, khng v, khi chy c nhiu

khi, gi thnh r, d gia cng bng phng php p v c di p sut, chu ho cht vnc cao...

V c nguyn t H C bc 3 linh ng nn H ny d tham gia phn ng oxi ho vth PS nhanh b lo ho trong khng kh khi c nh sng trc tip. Vng bezen c ththam gia phn ng sunfo ha, nitro ho,...dng sn xut nha trao i ion nh cationitaxit mnh.

PS khng phn cc do bn vi cc ho cht phn cc v phn cc mnh.PS c trng lng phn t thp rt gin v c bn khi ko cng b. dn di

tng i ca PS tng vt sau 80oC v trnn mm do nh cao su v dnh.-Khi lng ring d=1,05-1,1 g/cm3-Ch s chy MI: 1-8 g/10pht- bn ko t: 400-450 kg/cm2

Tnh cht PS huyn ph Dung dch Khi Nh tng

Gii hn bn un [KG/cm2] 816 875 800 900

bn va p [KG/cm/cm2] 14,7 15 15 180


22/79

bn nhit (Mactanh) [oC] 80 80 80 80

thm in mi (in thxuyn thng) (106 hex)

2,6 2,6 2,6 2,6

tg (106 hex) 0,0004 0,0006 0,0004 0,0008

3/ ng dng

-PS c lm vt liu cch in (iu kin khng ti hoc ti trng b v tnh)-Lm cc sn phm khc dng trong dn dng v cng nghip, phi bin tnh bng

cch ho do hoc ng trng hp vi cc monome khc.-PS xp dng lm vng my khi vn chuyn, cch m v nhit thp trong xy

dng


23/79

CHNG IV: CHT DO TRN CSCC POLYMERCA RU VINYLIC V CC DN XUT

A- SN XUT PVAxI/ Nguyn liu

Nguyn liu chnh sn xut polyvinyaxetat l vinyaxetat

Tnh cht: l mt cht lng trong sut, khng mi, t tan trong nc, tan trong dungmi hu c, c:

+ Nhit si ts= 73oC

+ Nhit ng bng t= -84oC

+ Nhit bc la tl = -5 -8oC

+ Khi lng ring 20oC 20= 0,934 (g/ml)+ nht 20oC = 0,432 Cp+ n nhit bc hi: 7,8 ( Kcal/mol)

+ ho tan trong nc 20

o

C : 2,5 %+ Cng thc cu to:

CH2 CH

OCO CH3 Tnh khng no: do trong mch c ni i nn VA c kh nng tham gia cc phn

ng cng, ng vng, oxi ho. C lin kt este nn tham gia phn ng thu phn vinc, ancol

CH2

CH

OCO CH3

C4H

9OH CH3 C OH

O

CH2

CH

O C4H9

+ +

* iu ch: C hai phng php+ Sn xut VA trong pha lng theo phng php gin on hoc lin tc.

Cho axetylen (C2H2) qua hn hp CH3COOH m c v anhydrit axetic c chasunfat thu ngn hoc phtphat thu ngn. Phn ng xy ra nhit 75-80oC, kt thc

phn ng C2H2 tha c tch ra v mt lng nh VA c a i x l.Vi phng php gin on cui qu trnh ta lm chm vn tc hp th C2H2

gim lng VA b tht thot v i xc tc mi.

Cn i vi phng php lin tc th lin tc cho C2H2, CH3COOH v cht xc tcmi vo thp phn ng ng thi lin tc tho xc tc phn ng ra.

Sn xut VA theo phng php pha kh th ngi ta tin hnh theo phng phplin tc. Cht xc tc thng dng l axetat km (CH3COO)2Zn hoc (CH3COO)2Cdc ph ln b mt than hot tnh sau sy kh. Nhit phn ng 170oC 240oC.Lc u nhit phn ng 170oC nhng sau do hot tnh ca xc tc gim nn tng


24/79

vn tc phn ng th nhit phi nng ln 210oC 220oC. hiu sut phn ng cao thdng t l C2H2 : CH3COOH = 9 : 1 khi hiu sut t c l 80 85%.

CH CH CH3 C OH

O

CH2

CH

OCO CH3

+

+ Phng php mi sn xut VA l phn gii diaxetat-etyl theo phng trnh phn ngcho hiu sut cao

CH3

CHOCH

3CO

OCOCH

3

CH3

CH (OCO CH3)2 CH2 CH

OCO CH3

CH3

COOH+ +

II/ L thuyt trng hp VA

Vinylaxetat d b trng hp di tc dng ca nh sng, nhit , cht kch ngv cht xc tc.

Nhit to ra do trng hp kh ln+ VA : 21,3 Kcal/mol+ MMA :13 - 13,6 Kcal/mol+ Styren : 16 17,5 Kcal/mol+ Etylen : 25 26 Kcal/molV vy khi trng hp VA cn mt nng lng kch ng kh ln, gy kh khn cho

qu trnh iu chnh.Cc monome c cha nguyn t C bc 3 c khuynh hng to ra polymer nhnh

ln do phn ng chuyn mch.

+ Chuyn mch qua monome

CH2

CH

OCO CH3

RH CH2 C

OCO CH3

R + +xt, tO

Hoc

CH2

CH

OCO CH3

RH CH2 CH

OCO C

H

HR + +

xt, tO

: gc polymerang pht trin. Nu trng hp tip tc th sinh ra nhnh.

Xc tc

Xc tc,to Xc tc,to

R


25/79

R CH2

C

OCO CH3

CH2

C

OCO

R

CH3

(a)

R CH2

CH

OCO C

H

HCH

2CH

OCO

R

CH2

(b)

+xt, tO

+xt, tO

Cch to nhnh theo kiu (a) nhiu hn (b)+ Chuyn mch cho phn t polymer khng hot ng

R.

+ R,H RH + R

,.

Mun lm gim s nhnh trong polymer hoc ta cho ngng phn ng trng hp mc chuyn ho thp. Hoc cho tin hnh phn ng trong dung mi hoc cho thm chtiu chnh (mecaptan, aldehyt...) c nguyn t H linh ng.

S chuyn mch t polymerang pht trin sang dung mi c m t nh sau:

R.

+ HA RH + A. (km hot ng)

III/ Sn xut PVAxC 4 phng php trng hp VA: trng hp khi, trng hp dung dch, trng hp

huyn ph v trng h p nh tng. Trong phng php trng h p khi t c sdng v to thnh khi PVAx gy kh khn cho cc cng on x l ti p theo (Tg =28oC). Trng hp huyn ph cng t c s dng, phng php c s dng ph binnht l trng hp nh tng.1/ Trng hp dung dch

Sn phm thu c dng lm sn, vecni, keo dn, sn xut PVAThnh phn hn hp phn ng+ Monome 100 PKL+ Dung mi 70 100 PKL+ Cht khi u [ (C6H5COO)2 ] 0,2 0,5 %+ Cht iu chnh ( C2H5CHO ) 0,01 0,1 %iu kin tin hnh phn ng

+ Dung mi ho tan c monome v+ Nhit phn ng ban u 75 80oC sau tng ln 85oC, hiu sut phn ng

t 98%+ Thi gian phn ng 4 6hKhi c mt ca dung mi th s phn tn nhit c ng u hn. Nhng nng

monome trong trng hp dung dch nh hn nng monome trong trng hp khi nn


26/79

vn tc phn ng khng cao v trng lng phn t b hn so vi trng hp khi v c schuyn mch, ngt mch vi dung mi.

Vinylaxetat tan tt trong cc dung mi etylaxetat, axeton, benzen, toluen, rutuyt i. Bn cht v nng dung mi khc nhau th dn n hiu sut v trng lng

phn t ca polymer cng khc nhau c th.

Nguynliu

Axeton Toluen Ru tuyti

Etylaxetat Benzen

Hiu sutto Po (%)

68,5 28 22,6 89,3 55

nht(Cp)

3 2,9 5,6 8,2 18,2

Ta thy ru tuyt i, benzen v toluen lm chm qu trnh trng hp VA, tc phn ng ln nht l tin hnh trng hp trong dung mi etylaxetat v axeton. Cn trong

dung mi benzen th polymer thu c c trng lng phn t cao nht, nu dng toluenth trng lng phn t rt thp mc d nhng tnh cht ca hai dung mi gn gingnhau.

Trong k thut dung mi thng dng trng hp VA l etylaxetat, axeton vbenzen. Ru etanol v metanol ch dng khi sn xut polymer tip tc x l thnhPVR v polyvinylaxetal.2/ Trng hp nh tng

C 2 loi nh tng : nh tng mn ht = 0,05 0,5 mnh tng th ht = 0,5 10 m

Thnh phn nh tng mn:+ VA : 100 PKL+ H2O : 100 120 PKL+ Cht nh ho C17H33COOK: 0,1 0,5 ( dung dch 10 15%)+ Cht khi u H2O2 : 0,5 1,5%+ Cht iu chnh C2H5CHO : 0,01 0,1%Chun b:+ Ho tan cht nh ha trong nc

+ Ho tan cht khi u trong t nc+ Ho tan dung dch cht iu chnh vo ncCc bc tin hnh trng hp:+ Cho ht dung dch nc v cht khi u vo thit b phn ng, cho cht nh ho

vo khuy u.+ Cho t t monome vo khuy u


27/79

+ un nng n nhit 65 70oC gi trong khong 1h, do phn ng to nhitnn nhit t nng ln 90oC, tip tc duy tr nhit ny trong khong 1,5 2h. Chocht iu chnh vo gn cui qu trnh, kt thc phn ng hiu sut chuyn ho t 98%

+ Lm lnh hn hp phn ng n 40oC, thm cc cht khc nu cn thit.+ Hm lng cht kh trong nh tng khong 50%

3/ Trng hp huyn phThnh phn nguyn liu:+ VA: 100 PKL+ H2O: 100 PKL+ (C6H5COO)2: 0,5 1 PKL+ Cht n nh huyn ph : 0,1 0,2 PKL ( dung dch PVA c 8 20 % nhm

axetat)S dy chuyn cng ngh

Hnh v: (xem sch)Cc bc tin hnh+ Chun b nguyn liu:

-Ho tan cht khi u vo monome-Ho tan PVA trong H2O-Trn hn hp dung dch cht khi u vo ht monome cn li

+ Tin hnh phn ngu tin cho ht phn nc vo thit b phn ng (6), cho dung dch PVA ho

tan trong nc vo ng thi tin hnh khuy trn. Ri cho t t hn hp VA v cht

khi u vo thit b phn ng. Thit b phn ng c v bc bn ngoi gia nhit chohn hp phn ng. Dng hi nc bo ho nng nhit ln khong 70 80oC ngthi khuy u lin tc to c cc git lng monome c dung dch PVA bao bcxung quanh. PVA c nht tng i ln nn ngn cng khng cho cc git monomednh li vi nhau. Khi un nng phn ng xy ra v to nhit nn nhit ca hn hp ttng ln 80 90oC, khi ta ng van hi nc li v mvan nc lnh ginhit ny trong vng 45 60 pht. Tip tc nng nhit ln n 90 95oC trong thi gian 30

35 pht. Tng thi gian phn ng ny mt khong 2h.Trong qu trnh phn ng hi monome v nc bay ra c cho vo thit b ngng

t lm lnh bng nc (7) ri cho hi lu trli thit b phn ng. Hiu sut chuyn hoca qu trnh khong 98 99%. Khng kh nn hoc N2 (nu dng khng kh nn th philc) c tc dng ngn khng cho khng kh bn ngoi vo trong thit b phn ng, ngthi khng cho hn hp bn trong thit b phn ng b trn. Khi cho kh nn vo th phing tt c cc van khc li. Hn hp phn to ra trong thit b (6) c chuyn sang thit

b cha (9), ti y hn hp c duy tr nhit 50oC gim nht, v trnh sa


28/79

lng th thit b phi c cnh khuy hot ng lin tc. Sau hn hp c chuyn sangmy ly tm (10), y dung dch nc thi em i x l cn cc ht polymer cchuyn sang xe gong (11) v theo h thng nng (12) i vo thit b sy (13). Ti thit bsy (13) nhit sy c duy tr 65 70oC trong iu kin chn khng vi thi giankhong 15-20 pht (y ch c tc dng lm kh nc ch khng sy kh trit , cc

ht polymer to ra c th ht m trli). Sau khi sy xong a vo my sng phn loiht th em i nghin nh ri trn li vi sn phm ht nh.

IV/ Cu to, tnh cht v ng dng ca PVAx1/ Cu to

Ngi ta dng phn ng x phng ha PVAx to thnh PVA nghin cu cutrc ca PVAx. Cc monome VA kt hp vi nhau to thnh polymer PVAx theo nguyntc u ni ui.

Cc phng php nghin cu:+ Khi oxi ho PVA bng HNO3 ta thy c to ra acid oxalic:

CH2

OCO

CH

CH3

CH2

OCO

CH

CH3

CH2

OH

CH CH2 CH

OH

HOOC COOH

+ Xt ph hp th th thy PVA c vch hp th ging 2,4-pentadiol

CH3

CH CH2

CH CH3

OH OH + Phn tch Rnghen ta thy PVA c cu trc -glycol.+ Dng phn ng oxi ho PVA bng HIO4 chng minh PVA c cha nhm -

glycol hay -glycol. Nu PVA c cha nhm -glycol tc l mch phn t PVA c cu

trc u ni u khi PVA d b oxi ho bng HIO4. Nu ta un nng PVA vi HIO4th thy nht gim nhng khng ng k, chng t lc u c phn ng t mch xyra nhng sau nht khng gim c ngha phn ng khng xy ra na.

Phn ng t mch PVA nh sau:

CH2

OH

CH CH2 CH

OH

CH CH2

CH CH2

CH

OH OH OH

HIO4

CHOCH2

OH

CH CH2 CH2 CH CH CH2 CH

OH OH

OH2+ +

Phn ng t mch xy ra mt s v tr u ni u, ui ni ui nhng vtr ny rt t nn nht gim t.

PVAx l mt polymer v nh hnh, nu mc ko cng ln (nh hng) cngkhng kt tinh v bn cht ca n khng nh hng c do nhiu nhnh v nhnh ln.

Polymer phn cc trung bnh yu = 2,3.10-18 debay, do vy tan tt trong cc dungmi phn cc tng ng.


29/79

2/ Tnh chta/ Tnh cht nhit:

+ PVAx c Tg = 28oC khi trng lng phn t trung bnh ln hn 30.000, nutrng lng phn t trung bnh thp 15.000 th Tg = 17oC

+ PVAx c th chy lnh( mu PVAx chu tc dng ca ti trng no y nhit

thng khng un nng, mu cng b bin dng chy)+ Khi un nng 170oC trln th PVAx b phn gii to CH3COOH

CH2

OCO

CH

CH3

CH2

OCO

CH

CH3

CH CH CH2 CHCH

3COOH

OCO CH3

+

Do lm cho polymer b vng, c th to polymer mng li khng gian khng

nng chy, khng ho tan trong bt k dung mi no. Kh nng to mng li khng gianl do mlin kt i trong mch.

b/ Tnh cht ho hc+ PVAx bn oxi ho, lo ho, nh sng+ PVAx tan trong cc dung mi: xton, este, dn xut ca HC, HC thm.+ PVAx phn cc trung bnh nn khng tan trong xng, du ho, HC bo mch

thng no, cc cht c phn cc ln: glycol, glyxerin.+ PVAx b trng trong nc v c th bn vi cc mui.+ PVAx b thu phn to PVA trong mi trng kim hoc axt+ Trn ln tt vi cc polymer: nitro xenlulo, cc dn xut khc ca xenlulo, cao

su clo ho, mt s polyeste, nha epoxy, phenolformaldehyt nhng khng trn ln vi ccnha alkyd, ure-formaldehyt v melamin-formaldehyt.

c/ Tnh cht chcPh thuc vo trng lng phn t trung bnh v phng php sn xut+ Khi lng ring d= 1,18 1,19 g/cm3

+ Gii hn bn ko (KG/cm3): -10oC 600

10oC 400

20oC 350

30oC 150 180

+ bn nhit (Vica, oC): 37+ ht nc (24h, to=20oC): 3%+ thm in mi (60 hex): 6,1+ tg (60 hex): 0,025

3/ ng dng+ sn xut PVA+ Lm sn, vecni, keo dn thng thng trn vi polymer khc

170OC


30/79

+ Dng PVAx nh tng dng trong xy dng tng Mac ca va ximng vximng btng, tng chng thm

+ Dng PVAx nh tng dng lm sn trong trang tr ni tht

B- SN XUT POLYVINYLALCOL (PVA)

I/ Sn xut PVAPhng php cbn sn xut PVA l thu phn (x phng ho ) PVAx nh

kim v axit ( NaOH, HCl, H2SO4l...) thng thng thu phn trong mi trng kim vidung mi l CH3OH.

Trng kp dng NaOH lm xc tc th cho PVAx tan trong CH3OH khan ncv sau x l bng mt lng nh (0,2 0,4%) dung dch NaOH trong CH3OH khannc. Gi hn hp nhit phng, PVA tch ra dng gel, dng phng php gn tch cht lng gm: CH3OH tha, axetat v nati axetat, cn PVA tan trong nc. Rtdung dch ny vo axeton (lng tha) kt ta PVA dng nguyn liu si trng, sch.iu chnh lng nc, nng PVAx v lng cht xc tc c th khng chc mc thu phn bt k. Sau em ly tm, ra, sy chn khng nhit 80 90oC n m 2 3% ( sy bay hi axeton i, cn ht vn m do PVA tan tt trong nc c thht m trli).

Trng hp dng HCl lm xc tc th nht ca PVA gim, c khi PVA khngtan trong nc v trong axit long. iu c l do PVA b mt mt s nhm hydroxyltrong qu trnh thu phn hoc trong thi gian sy. Rt kh kh vt axit c bit l axitH2SO4 ra khi PVA, v th axit cn li c th xc tin qu trnh kh hydro

CH2

CH CH2 CH

O C CH3

O

O C CH3

O

CH2

CH CH2 CH

OH OH

CH3COONa CH

3COOCH

3+ +

II/ Cu to v tnh cht ca PVA1/ Cu to

Dng polyvinylfocmiat th PVA to ra dng syndiotactic

CH=CH + HCOOH CH2=CH-OOC-H polyvinylformiatDng polyvinylbenzoat to PVA dng izotacticDng PVAx to hn hp 3 loi: izotactic, syndiotactic v atactic, trong atactic

chim ch yu nn PVAx l mt polymer v nh hnh.V c nhm OH phn cc v c lin kt H gia cc mch phn t nn Tg cao, Tg =

85oC v th gy kh khn cho qu trnh gia cng.2/ Tnh cht:

CH3OH, NaOH

to=30 - 40oC

Xc tc, to


31/79

C kh nng to ete, phn ng vi cc aldehyt to polyvinylaxetal

CH2

CH CH2 CH

OH OH

CH2O CH

2CH CH2 CH

O

CH2

O

+

polyvinylformal (form-va)CH

2CH CH2 CH

OH OH

C3H

7CHO CH

2CH CH2 CH

O

CH

O

C3H

7

+

but-va

Hai phn ng ny c ngha quan trngKhi un nng nhit cao (>200 250) th tch nc, to ni i. PVA tan

trong H2O ph thuc vo nhit v phn trm nhm CH3COO- c trong PVA+ Nu %CH3COO- < 5 th khng tan trong nc lnh m ch tan trong nc nng

(65 70oC) dung dch t nng ti a 10 12 %.+ Nu %CH3COO- = 20 th ho tan trong nc, khi un n nhit 30 35

oC rilm lnh th Po s lng xung.

+ Nu %CH3COO- = 50 th khng tan trong nc lnh v nng m ch trngnhng tan trong hn hp ru v nc ( thng dng CH3OH )

+ Ngoi nc PVA cn c th tan trong glycol thng, glyxerin, phenol, ure ( khiun nng )

Dung dch PVA bm dnh tt trng thi kh v khng b thi ra bi vi sinh vtnn dng lm keo dn giy, phong b.III/ ng dng

Nu PVA cha 15 20% nhm CH3COO- th dng lm keo dn. Dung dch PVAcho thm mt lng nh formalin dng lm keo dn giy, vi, da.

bn chc ca PVA nh hn polyamid-6, polyamid 6-6, axetat xenlulo, phenolformaldehyt, ure formaldehyt...

Si PVA x l bng dung dch CH2O c dng lm si cu, li nh c. Ngm

si PVA c x l bng CH2O trong nc bin trong vng 95 thng th bn thay ikhng ng k.

Si PVA x l ho hc bng CH2O kt hp vi si Visco dit vi may mc, mts ni gi l si vinylong


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CHNG V: CHT DO I TCC DN XUT CA AXIT ACRYLICV AXIT METAACRYLIC

Axit polyacrylic v polymetaacrylic ng trng hp vi divinyl benzen ( 10 15%khi lng ) dng lm nha trao i ion loi cationit

* CH2 nCH CH2 CHCOOH

CH CH2

Polyacylat v polymetyl-metaacrylat, polyacrylonitril, polybutylmetaacrylat l ccloi nha thng thng.

Polyacrylonitril c Tg > nhit phn hu do phi dng dng ng trng hpch khng dng dng n trng hp, n khng tan trong bt c dung mi no.

I/ Nguyn liu chnh1/ Axit acrylic ( CH2=CH-COOH ) l axit hu ckhng no, n gin nht, c kh nngtrng hp v ng trng hp. C nhiu phng php sn xut axit acrylic.

+ Phng php tng hp Reppe iu ch trc tip t C2H2, CO, H2O ( CO ciu ch t ttracacbonyl niken ho tan trong HCl )

CH CH OH2

ClH Ni(CO)4 CH2 CH COOH NiCl2 CH2+ + 1/2 + 1/4 + 1/4 + 1/4 + Phng php c in: oxi ha acrolin bng khng kh trong mi trng

CH3COOH m c 20 40oC c oxit bc hoc oxit vanadi

+ Nhng tin nht l:CH

2CH

2

O

HCN CH2 CH2 CN

OH

+

etylenxianhydril

CH2

CH2

CN

OH

OH2 H2SO4

CH2

CH COOH (NH4)HSO4+ + +

Axit acrylic l cht lng khng mu, c mi hc tan trong nc v cc dung mi

hu ctheo bt c t l no.

Khi khng c peroxit, trong mi trng N2 v nhit n 180oC vn khng btrng hp. Ngc li nu c mt lng nh oxi hoc peroxit vo th d to ra Po.2/ Este ca axit acrylic ( CH2=CH-COOR )

Trong cc este ca axit acrylic th metyl, etyl, butyl acrylat c dng nhiu nhtNgi ta tng hp este acrylic t etylenxianhydrin

95OC


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CH2

CH2

CN

OH

ROH H2SO

4CH

2CH COOR (NH4)HSO4+ + +

Este tinh khit d b trng hp ngay nhit phng.

3/ Axit metaacrylicCH

2C COOH

CH3

Nhn axeton xianhydrin t axeton v HCN

CH3

CO CH3

HCN CH3

C(CH3) CN

OH

+

Kh H2O v x phng ha axeton xianhydrin bng H2SO4.

CH3

C(CH3) CN

OH

CH2

C COOH

CH3

Axit metaacrylic l cht lng, khng mu, si 160oC.4/ Este ca axit metaacrylic ( CH2=C(CH3)-COOR )

Metyl metaacrylat v butyl metaacrylat c dng nhiu nht. Phng php chungl kh H2O, x phng ho v ete ho axeton xianhydrin bng ru tng ng.

CH3 C(CH3) CN

OH

ROH H2SO4 CH2 C(CH3) COOR(NH

4)HSO

4+ + +

Tn Nhit si (oC) Khi lng ring (g/ml)

CH2=CH-COOH 141 1,0487 (20oC)

CH2=C(CH3)-COOH 160 1,015 (20oC)

CH2=CH-COO-CH3 80 0,952

CH2=CH-COO-C2H5 99,5 100 0,919

CH2=C(CH3)-COO-CH3 100,3 0,937

CH2=C(CH3)-COO-C2H5 117 0,911

* Nhn xt:Thay H linh ng (1) bng CH3- trthnh (2) th nhit si cao hn do s cn

trchuyn ng quay ca nhm CH3, ng thi khi lng ring ca (2) cng nh hn do

cng knh v mt sp xp khng gian ca mch i phn t. Nhit si thp nht lmetylacrylat v khi lng ring th p nht l etyl metaacrylat. Quy lut trng hp camonome ny cng ging nh cc monome ca dn xut vinyl, ch khc viu kin trnghp.* Xt MMA

MMA c nhit trng hp thp ( nh hn Styren ) nn MMA d trng hp. MMA trongqu trnh bo qun nu tip xc vi nh sng c bc sng ngn, oxi khng kh th n t


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trng hp. Do trong qu trnh bo qun cn phi cho thm cc cht c ch (hay hmtrng hp) l cc cht c H linh ng, ph bin nht l hydroquinon. V vy trc khi tinhnh trng hp th tch lng hydroquinon ny ra khi monome bng dung dch NaOHnhng hm lng ch nhiu hn mt t so vi hydroquinon v nng xt phi long.

CH2 C

COOCH3

CH3

NaOH CH2 C

CH3

COONa

CH3OH+ +

II/ Nguyn tc trng hpC th trng h p theo mt trong 4 phng php: trng hp khi, trng hp dung

dch, trng hp nh tng , trng hp huyn ph.1/ Trng hp khiThnh phn nguyn liu:

+ MMA: 100 PKL

+ Hn hp cht khi u ( peroxit benzoic:azodiizo butyronitril = 2:1 ): 0,02 1%S dng hn hp cht khi u gim tc oxi ho ca peroxit benzoic.Qu trnh phn ng:

+ Chun b nguyn liu: trn cht khi u vi mt t MMA ri sau cho hnhp ny trn vi lng MMA cn li.

+ Tin hnh gia nhit cho hn hp phn ng, ban u duy tr nht 70 80oC,phn ng to nhit nn s t nmg ln 80 -90oC. Khi hiu xut chuyn ho ca hn hpt 30 40% tin hnh vo cc khun nh c dung tch 5 10 lt v vn ginhit 80 90oC, tip tc trng hp trong l sy vi thi gian 4 6 ngy. Nhit sy trong lc iu chnh nh sau:

80 - 90oC trong 1 2 ngy.

90 95oC trong 1 ngy.

95 110oC trong 1,5 ngy.

110 120oC trong 1 ngy. co ngt th tch khi trng hp khi l 20,1%

Trong qu trnh sy nng nhit t t trnh hin tng monome bc hi to lxp v hm lng monome cn li trong sn phm cui cng 0,5 1%. Trng hp khi

c ng dng nhiu nht trong sn xut PMMA. nng cao hiu xut ng thi gim co ngt ca sn phm ngi ta tin hnh

trng h p MMA theo mt phng php khc: trn MMA vi mt lng xirp caPMMA v cht khi u ri tin hnh trng hp theo trnh t cc bc nh trn.2/ Trng hp dung dch


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Bn cht v hm lng dung mi nh hng n trng lng phn t trung bnhca Po, vn tc ca phn ng. Dung mi tt nht dng trng hp l benzen do hng schuyn mch, ngt mch b nht.

Trong dung mi khng phn cc phn ln polmer c cu to izotactic, trong dungmi c cc th to ra polymer c cu to syndiotactic.

3/ Trng hp nh tngPhng php ny rt c hiu qu sn xut nhiu polymer ca ete axit acrylic v

metaacrylic. Dng nhiu nht l latex ca polyetyl v polymetylacrylat ph ln b mtda, giy... tuy nhin mng nhn t phng php ny km bn hn mng nhn t dungdch trong cc dung mi hu c.

X phng natri v amn l cc cht nh ho tt nhng khi dng chng th mitrng kim to ra v monome nhiu hay t cng b x phng ho. V vy nn tin hnh

phn ng trong mi trng trung tnh hoc axit yu. Cch trng h p ging vi trnghp styren.4/ Trng hp huyn phPhng php ny c dng ph bin gn nh trng hp khi

- T l th tch: H2O/MMA = 2/1 n ti a 4/1.- Cht n nh huyn ph: jelatin, metylxenlulo, PVA (8 -12% nhm axetat t do):

0,05 0,2% so vi monome.Cht n nh tan tt trong nc, khng tan trong monome, dung dch c nht ln.

Nng cht n nh trong mi trng nc 15 20%.- Cht khi u: hn h p peroxit benzoic v azodiizobutyronitril vi hm lng:

0,01 1%.- Cht mu hu c tan trong monome, bn mu, khng c nh hng n qu

trnh phn ng.Qu trnh tin hnh:

Ban u duy tr nhit 80oC sau nng dn nhit ln 90, 95, 98oC trongkhong thi gian 2,5 3h. Nhit cui ca qu trnh duy tr 100 110oC trong vng 30

pht v kt thc. Tng thi gian phn ng 4,5 5h. Hm lng monome t do cn litrong hn hp sau phn ng nh hn 1%.

Sau tin hnh ly tm, ra bng nc nhit 65 70oC ngay trong thit b lytm. Ra bng nc m tch cc cht n nh huyn ph, cht iu chnh... c trit. em sy nhit 75 80oC trong thi gian 30 pht ri tin hnh to ht, ng bao.

III/ Cu to, tnh cht v ng dng ca PMMA1/ Cu to

Nghin cu cc dn xut ca polyacrylic thy rng cu trc ca chng c th uni ui v u ni u. Tt c cc polymer ca ete acrylic v meta acrylic l nhng


36/79

sn phm khng mu, trong sut, cng, n hi, chng u l nhng nha nhit do dgia cng theo nhiu phng php khc nhau.2/ Tnh chta/ Tnh cht ho hc

- PMMA bn vi cc ho cht iu kin thng nh: dung dch nc mui, dung

dch kim long, dung dch axit long...- PMMA t ht nc, khng tc dng vi ru, cht bo v du khong.

b/ Tnh cht nhitPMMA c nhit ho thu tinh Tg = 80oC

Nhn xt:(1): khi gc R c 1C th Tg = 80oC, khi tng s nguyn t C th Tg gim n 12C th

Tg bt u tng trli.

(2): khi R c 1C th Tg = 0oC, khi tng s nguyn t C th Tg gim n 8C th Tg tngnhanh hn so vi ng (1)

Gii thch:

CH2

C

COO

CH3

*

Rn

Khi tng R th n c tc dng che chn nhm phn cc lm Tg gim.Khi tng Rn ln hn 12C th tc dng che chn khng cn na ( ti 12C th hiu ng

che chn t ti hn ) m khi s sinh ra s cn trkhng gian ln lm nh hng nchuyn ng nhit ca cc mc xch, v th Tg tng trli. Xt ng (2) c Tg thp hnv khng c nhm CH3- nn mch phn t mm hn so vi (1).

PMMA khi nhit ln hn 180oC th bt u b phn hu, khi nhit cao hn250oC th qu trnh phn hu xy ra nhanh hn ( hiu sut phn hut 75 80%)c/ Tnh cht quang hc

C O R

Tg(oC)

S nguyn t C trong gc R1-60

8 12 16

-20

0

80

(1)

(2)


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PMMA cho qua 91 -92% tia trong thy, 75% tia t ngoi, cho qua hu ht tia hngngoi. PMMA rt trong sut, khi dy tm 6,5 m th trong sut gim 50%.d/ Tnh cht chcXt polyalkyl metaacrylat

Tnh cht -CH3 -C2H5 n-C3H7- n-C4H9- Izobutyl

d (g/cm3) 1,19 1,11 1,06 1,05 1,02ko(KG/cm

2) 630 350 280 70 240

bn va p(KG.cm/cm2) 10,5 7,1 6,5 11,5 1,6

Nhit chy mm(oC) 125 65 38 30 70


38/79

CHNG VI: CHT DO I TCC POLYMER CA DN XUTHALOGEN ETYLEN

SN XUT PVCI/ Nguyn liu

Nguyn liu sn xut PVC l vinylclorua C2H3Cl

CH2 CH

Cl L cht kh khng mu, c mi ete nh, khng tan trong nc nhng tan trong cc

dung mi hu cnh axeton, ru etylic, HC thm, HC mch thng.PVC c cc thng s vt l nh sau:+ Nhit si ts= -13,9

oC+ Nhit nng chy tnc= -159

oC+ Khi lng ring -12,96oC d= 0,9692 g/cm3

+ nht -20o

C = 2,81 Cp+ n nhit ho hi: 85,7 Kcal/kg+ To hn hp n vi khng kh: 4 21,7% th tch+ Nng VC cho php trong 1 lt khng kh: 1mg/lVinylclorua c thng trng hp vi nhiu cht khc nhau

* Sn xut vinylcloruaKh hydro v clo ca diclotan bng dung dch ru kim

CH2

CH2

ClCl

NaOH CH2 CH

Cl

NaCl OH2+ + +

Phng php ny khng kinh t tn nhiu NaOH, ru v thit b phi ln+ Clo ho etylen nhit cao

CH2 CH2 Cl2 CH2 CHCl ClH

FeCl3

+ +

Phng php ny cha dng trong cng nghip v cha c phng php ly nhitphn ng ra.

+ Nhit phn dicloetan

CH2

CH2

ClCl

CH2

CHCl ClH+

Phng php ny rt kinh t, dy chuyn sn xut n gin nhng xc tc khng

bn, khng ti sinh c v nhit cao to ra sn phm ph nh C2H2, dien...+ Hidro v clo ho C2H2

CH CH ClH CH2 CHCl+

(450-600OC)

(Al2O3 , C hot tnh)

500-590o

C

p= 4 - 6atm, to= 200oC

Xtc HgCl2/cht mangaluminosilicat


39/79

Phng php ny cng c dng ph bin trn th gii: qu trnh thc hin lintc trong thit b tip xc loi ng 160 200oC. Xc tc l clorua thu ngn ph ln bmt than hot tnh mt lng 10 - 15%. Kh C2H2 v HCl lm sch, sy kh cho vo thit

b phn ng. Cho cht xc tc vo trong cc ng ca thit b phn ng v khong cchgia cc ng cho du tun hon nhit 70 130oC. Khi nhit t 70oC xc tc bt

u lm vic th nhit ca phn ng t n 160oC. Hn h p sau phn ng gm:vinylclorua to ra, dicloetan, axetaldehyt, axetilen, HCl c a qua thit b phun dngnc v dung dch kim 10% ra kh mc ch l hp th kh HCl. Sau cho vothp sy bng KOH rn ri qua thit b lm lnh n 40oC ngng t VC v hp cht cnhit si cao hn. Sau qu trnh ngng t cho qua thp tinh luyn hot ng lin tc ui sch axetaldehyt, dicloetan v cc sn phm ph khc. Sau VC c tch ra khiC2H2 ho tan trong thit b chng ct khc.

II/ L thuyt trng hp vinylcloruaNu khng c oxi v cht khi u ch c nhit th vn tc phn ng b. Khi c

mt cht khi u (C6H5COO)2, cat-19 v cat-29 (dng hn hp 2 cat th iu chnh trnglng phn t trung bnh v vn tc phn ng c d dng) th tc phn ng ln.

Tp cht nh hng ln n phn ng trng hp: C2H2, CH3OH, C2H5OH, HCl thlm chm tc phn ng cn Styren, hidroquinon, rezoxin, anilin, phenol...lm ngnghn qu trnh.

Khi trng hp VC th rt nhy vi nhit c bit trong dung mi. Trong trnghp nh tng, huyn ph, dung dch th nhit trng hp 35 55oC khi nhit ln hn75oC th % Cl trong sn phm gim xung do kh to HCl ng thi hnh thnh lin kt

i lm cho sn phm c mu.Nghin cu trng hp VC trong khi c cht kch ng th thy rng trng hp xy

ra theo cch chui gc bnh thng nhng c nt c bit:+ Vn tc trng hp tng t lc bt u phn ng n khi hiu sut chuyn ho t

gn 50% th chm li, hin tng gi l hiu ng gel.+ Vn tc chuyn mch c gi tr ln hn rt nhiu so vi trng hp nhng hp

cht vinyl khc.nh hng ca dung mi v nhit n mc trng hp v % Clo trong sn phm.

Dung mi Nhit phn ng(oC)

Mc trng hp(n)

Hm lng clotrong PVC (%)

CH3OH 80 310 55,98

Toluen 85 87 53,3

n-hexan 80 295 55,75

Diocxan 80 100 55,52


40/79

Nhn xt: trng hp trong toluen th nhit phn ng cao hn nn trng lngphn t trung bnh nh. Tt c hm lng clo u b hn theo l thuyt l 56,8% ngha lc 1 mc xch th c 1 nguyn t clo. Ba dung mi u ch ho tan VC khng ho tanPVC cn diocxan ho tan t PVC.

Trng hp VC c peroxit benzoic th trng lng phn t trung bnh ca polymer:

+ Thc t khng ph thuc vo nng cht khi u trong gii hn di 2%, nunng cao hn th trng lng phn t trung bnh gim nhanh.

+ Trng lng phn t trung bnh khng ph thuc vo mc chuyn homonome

+ Trng lng phn t trung bnh gim khi tng nhit trng hp.

III/ Cc phng php trng hp VC1/ Trng hp VC trong khi

Phng php ny t c s dng v polymer thu c dng khi gy kh khncho cng on gia cng sau ny. Qu trnh phn ng kh ly nhit ra lm phn hu

polymer to kh HCl v lm cho polymer c mu.2/ Trng hp VC trong dung miC th dng hai loi dung mi:

- Dung mi khng ho tan polymer ( hay dng ru ): trong trng h p ny snphm cui cng ca phn ng l polymer dn dn tch ra dng bt mn.

- Dung mi ho tan c monome v ( hay dng dicloetan, axeton...) sn phm thuc dng dung dch, mun tch ra th phi tin hnh kt ta hoc chng ct loi bht dung mi.

Phng php ny t dng trong thc t do qu trnh trng hp lu v tn nhiu nhiudung mi.3/ Trng hp VC trong nh tng

Cht khi u thng dng l H2O2, pesulfat kim loi kim. Cht nh ho l ccloi x phng ncal ( mui natri ca axit izobutyl sulfonaphtalenic ) dng vi lng 0,1 0,5% trng lng nc.

Dng thm mui m gi nguyn pH, thng thng pH = 4 9. Mui mhay dng l axetat kim loi nng, phtphat, cacbonat kim loi kim...

Vinylclorua trc khi trng hp nn cho qua than hot tnh nhit 70 80oChoc sc qua dung dch NaOH hay KOH nng 25 60%4/ Trng hp VC trong huyn phThnh phn nguyn liu

Nguyn liu I II

Vinylclorua 100 100

H2O 150 20 100


41/79

Cht n nh huyn ph PVA (15% nhm CH3-)dung dch 5% trong nc

Jelatin: 0,5 2%

Cht khi u (peroxit benzoic) 0,04 0,04 0,6%

Ngoi ra c th thm cht ngt mch phn ng AD-3 ( diphenylol propan)

HO C

CH3

CH3

OH

Cht n nh nhit AD-5: C35H50O3

HO C17

H37CH2 CH2 CO

O

C(CH3)3

C(CH3)3

S dy chuyn cng nghHnh v: (xem sch)

u tin phi chun b kn ca thit b phn ng (1) bng cch cho nn N2psut p= 4 5atm trong thi gian 5 -10 pht sau tho v p sut thng. Chun b dungdch cht n nh huyn ph, lc (3) vo (2) cha ri vo (1). Cho H2O tnh vothit b, cho tip dung dch n nh huyn ph v tin hnh khuy trn vi vn tc cnhkhuy 60 80 vng/pht trong thi gian 2 3pht ri ngng khuy. Tip tc cho kh N2vo ui ht khng kh trong thit b phn ng ( khng cn p sut cao). Cho t t VC

vo ri cho dung dch cht khi u vo gi p sut 7 8atm ng thi tin hnh khuytrn trong thi gian 30 pht, khi to ra cc git monome c bao bc bi dung dchcht n nh huyn ph. Nhit ban u ca phn ng 40 55oC thi gian cui c thnng ln 60oC ngt mch.

Ra khi thit b phn ng hn hp qua thng cha (7) lm vic p sut thng,trc tin cho xt vo o pH ng thi sc hi nc qu nhit vo nhm ui VC t dov kh khc. Hi nc qu nhit sc vo trong 30 pht, VC khng phn ng b hp th

bi PVC bay ra theo ng hn hp kh ra. Hoc y ht VC v kh khc th sc khN2 vo p sut khng ln. Trong thit b (7) phi tin hnh khuy lin tc PVC

khng b sa lng. Sau khi tch ht VC t do, hn hp PVC c a qua thit b lytm. Cht lng tch ra ban u cn nhiu NaOH nn cho vo thng (9), nc m dng ra nha sau khi ly tm c cho vo thit b (10) ri em i x l. PVC bt mn lngxung y ca thit b (9), (10) c tch ra v thu hi. Ly tm xong bt PVC c hm mtng i ln nn cho qua thit b sy (11). Bt PVC c th sy theo nhiu phng phpkhc nhau: sy pht bng khng kh nng (thi gian sy 30 45 pht, nhit ca khng


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kh nng 95 105oC), sy tng sibt PVC sau khi sy c hm m W 0,5%. Cuicng chuyn sang cng on sng, ng bao.

IV/ Cu to, tnh cht v ng dng PVC1/ Cu to ca PVC

Trng h p VC theo c ch gc t do l s kt cc phn t theo u ni ui

thnh mch pht trin.CH

2CH

Cl

CH2

CH

Cl

CH2

CH

Cl Ngi ta dng nhiu phng php ho hc, Rnghen v quang hc chng

minh cu to ca PVC:+ Cho tia phng x xuyn vo PVC th xy ra qu trnh kh HCl v to thnh ni

i cch mt trong polymer.+ Quang ph t ngoi hp th PVC cng tng ng vi quang ph hp th 2,4-

diclobutan hoc nhiu hn l vi quang ph hp th 2,3-diclobutan.+ Cho KI tc dng vi dung dch PVC th khng thy I2 t do thot ra ( I2 t dothot ra khi KI tc dng vi cc cht m cc nguyn t Cl ni lin vi hai nguyn t Ccnh nhau)

PVC cng c cu to nhnh nhng rt t, t 50 100 mc xch mi c mt nhnh.PVC l mt polymer phn cc mnh. trng thi khng ko cng PVC hon ton v nhhnh, ch khi no ko cng tht mnh mi c kh nng nh hng mt phn.2/ Tnh chta/ ha tan: polymer phn t thp vi n=300 500 tng i d tan trong axeton,

kton, este, xiclohexanol...Khi trng lng phn t trung bnh cao th PVC rt kh ho tan(1 10%) tan trong: dicloetan, clo benzen, diocxan, tetrahidrofuran.

iu kin ngui PVC khng tan trong cc cht ho do nhng nhit cao thb trng nhiu v c trng hp li tan. Polymerdng nh tng c ho tan kmhn polymer huyn ph, polymer dung dch.

b/ Tnh cht nhitNhit chy mm ca PVC cao hn mt t so vi nhit phn hu ca n.

PVC khng bn nhit, ngay 140oC bt u phn hu chm v 170oC th nhanh hn

khi HCl b tch ra lm bin mu sn phm v mt tnh tan. Mt tnh tan ca PVC l doto ra lin kt ngang

CH2

CH

Cl

CH2

CH

Cl

CH2

CH

Cl

CH2

CH

Cl

CH2

C CH CH

CH2

CH CH2 CH

Cl

Cl

-2HCl


43/79

Bin mu ca PVC l do to ra lin kt i

CH2

CH

Cl

CH2

CH

Cl

CH2

CH

Cl

CH CH CH CH CH CH

n nh nhit ca PVC ta thm cht n nh vo theo 4 nhm: hp th kh HCl,

cht trung ho HCl, cht ngn chn tc dng ca O2 v cht hp th tia t ngoi.c/ bn ho hcPVC l mt polymer bn ha hc cao lm cc thng cha, ng dn ho cht (axit, kim,mui...)d/ Tnh cht chc

- Tg = 78 80oC- d = 1,38 1,4 (g/cm3)- k= 400 600 (KG/cm

2)

- u = 900 1200 (KG/cm

2

)- n = 800 1600 (KG/cm2)

- = 10 25%- bn va p = 70 160 (KG/cm2)- bn nhit (Mactanh) = 65 70oC- Nhit gin = -10oC

+ Kh nng trn ln vi cc cht khcVi polymer: PVC trn c vi phenolformaldehyt, epoxy...Vi cht ho do: PVC trn c vi hu ht cht ho do loi este phn t thp nh:

DOP, DBP, tricrezylphotphat...3/ ng dng

PVC cng ( khng c cht ho do) lm tm, ng dn, vt liu cch inPVC mm: ng dn mm, bc dy in, mng mng, da gi

-HCl


44/79

PHN IICNG NGH SN XUT MT S POLYMER TRNG NGNG

CHNG VII: SN XUT NHA PHENOL-FORMALDEHYTI/ Nguyn liu1/ Cc phenol

a/ Phenol C6H5OHPhenol tn ti dng tinh th hnh kim, khng mu v c mi hc c trng.

lu trong khng kh phenol c mu hng, nu c mt ng, st, amoniac th phenol dbin mu nhanh hn v chuyn sang mu nu nht.

+ d (45oC) = 1,0545 g/cm3+ tnc = 40,9

oC+ ts = 182,2

oCPhenol l cht ht m, nhit thng tan n 27% trong nc to thnh dung

dch ng nht. Phenol rt c, gy bng da v kch thch nim mc. Nng gii hncho php trong khng kh l 0,005 mg/l.

* Tnh cht ho hcPhn ng to mui phenolat

C6H5OH + NaOH C6H5ONa + H2OPhn ng th SE v nhm OH- l nhm th loi mt nn n nh hng ch yu

vo v tr octo hay para.Phn ng halogen ho

OH

Br2

OH

Br

Br

Br

+

* iu ch phenolPhng php i t than : khi cc ho than thu c nha than , sau chng

nha ny ta c du nh ( hydrocacbon thm ), du trung ( phenol, crezol, xylenol,naphtalen) v du nng.

Phng php tng hp:+ Phng php benzosunfonat: cho sunfo ho benzen ri trung ho benzosunfonic

axit bng cch un nng chy n vi kim, phn gii phenolat v chng phenol.+ Phng php clobenzen: cho clo ha benzen, sau cho clobenzen tc dng vi

dung dch NaOH 10% theo t l 1 :1,25 vi iu kin phn ng nhit 400oC.+ Phng php Rasic: cho benzen tc dng vi HCl v khng kh nhit 200

230oC vi xc tc l mui nhm, st hoc ng. Tch clobenzen v thu phn trong mitrng kim nhit 350oC vi xc tc l SiO2 hay Ca3(PO4)2. Sau ra phenol bngnc, tin hnh chng ct cui cng thu c phenol.


45/79

+ Phng php Cumen: iu ch izopropylbenzen khi c xc tc, sau oxy hoizopropylbenzen bng oxi khng kh c thm cht nh ho 85oC. Tip tc thu phn sn

phm va mi to ra bng dung dch H2SO4 10% thnh phenol v axeton. Sau dngphng php chng ct tch phenol.b/ Mt s phenol khc

+ Crezol ( CH3C6H4OH )OH

CH3

OH

CH3

OH

CH3

o-crezol(35%) m-crezol(37-49%) p-crezo(25%) + Xilenol (CH3)2C6H3OHc tch ra t phn c nhit si cao nht ca du trung ( 210 25oC) c 6 ng phn

OHCH

3

CH3

OHCH

3

CH3

OHCH

3

CH3

OHCH

3CH

3

OH

CH3

CH3

OH

CH3CH

3

1,2,3 Xilenol 1,2,4 Xilenol 1,2,5 Xilenol

1,2,6 Xilenol 1,3,4 Xilenol 1,3,5 Xilenol + Rezorsin: C6H4(OH)2

OH

OH Rezorsin c 3 v tr hot ng rt mnh hn phenol

2/ Cc andehyta/ Formaldehyt (andehyt formic) CH2OH C H

O * Tnh cht vt l

iu kin thng formaldehyt l mt cht kh khng mu, c mi hc, gy kchthch nim mc.


46/79

+ d = 0,8153 g/cm3+ tnc = -92

oC+ ts = -21

oCFormaldehyt dng ch yu dng dung dch nc gi l formalin. Formalin cha

33 40% th tch formaldehyt tng ng vi 33 37% theo khi lng.

* Tnh cht ho hcFormaldehyt c kh nng t trng hp nhit thp to thnh nha

polyformaldehyt (parafoc) v khi un nng th phn hu cho ra li formaldehyt.

HCHO * CH2On

* CH2On

HCHO

n

n

Parafoc l polymer v nh hnh c mu trng. V d trng hp nhit thng

nn khi bo qun ta cho vo 7 12% ru metylic.Formaldehyt d tan trong nc khi trong nc n dng hydrat ho

(metylenglycol)HCOH + H2O HO CH2 OH

Dng hydrat ho ny d bt c nng no cng to ra polyoxymetylglycol2 HO CH2 OH HO CH2 O CH2 OH + H2O

HO CH2 O CH2 OH + n HO CH2 OH HO-(-CH2O-)n+1CH2OH + H2O* iu ch formaldehyt

Oxy ho ru metylic:2CH3OH + O2 2 HCHO + H2O + 36,8 Kcal/mol

CH3OH HCHO + H2 - 28,8 Kcal/molPhng php oxy ho kh metan

CH4 + O2 HCHO + H2O (phn ng chnh)2 CH4 + O2 2CH3OH (phn ng ph)

b/ Cc andehyt khcFurfurol C5H4O2

CH CH

C CHO

O

CH

Urtrpin (CH2)6N4

II/ L thuyt trng ngng phenol vi formaldehyt* Phn loi

Vi n= 3 -5

Xt, 400-600oC


47/79

Tu thuc vo xc tc v t l cu t m chia nha PF ra lm 2 loi: nha novolacv nha rezolic.

Nha novolac: dng xc tc ion H+ ( cc axit thng dng l HCl, c khi dngH2SO4) t l C6H5OH/CH2O = 6/5 hoc 7/6

Nha rezolic xc tc l OH- ( hay dng NaOH, NH4OH, Ba(OH)2...). Dng xt lm

xc tc th nha to ra tan trong nc thnh h nh tng. Dng NH4OH lm xc tc thnha to ra khng tan trong nc m tan trong cn. T l C6H5OH/CH2O = 5/6 hoc 6/7.* Cc yu tnh hng n qu trnh trng ngng+ Cu to ho hc ca nguyn liu

Cu to khc nhau th nh chc khc nhau dn n kh nng phn ng khcnhau. Nha nhit rn c iu ch t cc nguyn liu cha phenol c 3 v tr hot ngnh phenol, m-crezol, 1,3,5-xylenol, v rezorsin. Cn cc andehyt th ch c formaldehytv furfurol l to nha nhit rn.

Nha nhit do c thiu ch t nguyn liu cha cc phenol c 2 v tr hotng nh octo v para-crezol; 1,2,3 hay 1,3,4-xylenol. Do ch c hai v tr hot ng tcl nhm metyl khng lm hot ho cc nguyn t hydro bn cnh nhn thm nn khngc kh nng to nha nhit rn. Cc nhm hydroxyl ca phenol khng tham gia phn nga t.+ T l mol C6H5OH/CH2O

Nu t l mol P:F = 1:1 th ch yu to ra cc octo v para monometylol phenol.T cc ru phenol ny tip tc a t to thnh nha nhit do.

Nu t l mol P:F = 1:2 hoc cao hn th ch yu to ra cc di v tri metylol

phenol. T cc ru phenol ny tip tc ngng t to thnh nha PF khng nng chy,khng ho ho tan.+ pH ca mi trng

pH < 7 th cc ru phenol to thnh khng bn, n nhanh chng ngng t vinhau hoc vi phenol to nha nhit do.

pH > 7 th cc ru phenol to thnh rt bn, cc di, tri metylol tip tc trngngng vi nhau hoc vi phenol to thnh polymer nhit rn.* Nguyn tc trng ngng+ Novolac

OH

CH2O

OH

CH2

OH+

monometylol phenolRt t dimetylol phenol c to:


48/79

OH

CH2

OH

CH2OH

dimetylol phenol

V trong mi trng axit nn tc phn ng cu nhm metylol ln. Phn ngtrng ngng to nha c thc vit nh sau:

OH

CH2

OH

OH OHOH

CH2

OHOH

CH2

OH

HOCH2

OH

CH2

OHOH

CH2

H+

H+

OH

CH2

OH

OH

HOCH2

H+

OH

CH2

OH

CH2

O

+

+

+

cu ni metylen ete

Cu ni metylen ete khi p, gia cng nhit cao th b phn hu to ra CH2O.- CH2 O CH2 - - CH2 - + CH2O

Cng thc tng qut ca nha Novolac:

OH

CH2

OHOH

CH2

n

+ RezolicXc tc l OH- (NaOH, Ba(OH)2, NH4OH...)

- NaOH l xc tc mnh, lm mu nha ti ( nu sm), tan c trong nc khtch lp tc l dng nh tng trong nc.

- Ba(OH)2 cho nha mu sng hn

- NH4OH l xc tc yu, nha c mu sng v phn lp mnhPhn ng to nha

OH

CH2O

OH

CH2

OH

CH2OH

OH-

OH

CH2

OH

OH

CH2

OH

CH2OH

HOCH2

+


49/79

Trong mi trng OH- th cc nhm metylol c vn tc phn ng b.OH

CH2

OH

CH2OH

OH

CH2

OH

OH

CH2

OH

CH2OH

HOCH2

OH-

OH

CH2

O

CH2OH

CH2

OH

CH2

OH

CH2

OH

CH2OH

CH2

n

OH

+ +

Nha rezolic c metylol t do v tr para ca phenol nn c kh nng ng rn

nhit thch hp to nhnh mng li khng gian khng nng chy, khng ho tan.III/ Quy trnh sn xut nha phenol-formaldehyt

1/ Nha NovolacThnh phn nguyn liu

C6H5OH 100 PKLCH2O 26,5 27,5 PKLHCl (d= 1,19) ln 1: n pH = 1,6 2,3

ln 2: 0,056 PKLAxit oleic: 1,5 2 PKLCho ht formaldehyt ( C%=37%) v phenol vo thit b phn ng ri khuy u,

sau cho axit ln 1 vo trong lc cnh khuy vn hot ng. Mc ch ca vic choaxit ln 1 l h pH ca formaldehyt v ng thi lm mi trng xc tc. Tin hnhun nng n nhit 80 85oC phn ng to nhit nn nhit ca hn hp t tng ln95 98oC, lc ny hn hp bc u si. Duy tr nhit ny trong khong thi gian 30

pht. Tin hnh cho axit ln hai v ginhit si ts=98oC trong thi gian 45 50pht,

cng trong thi gian ny ngi ta ly mu th xc nh d = 1,17 1,2 g/ml. Khi phnng kt thc tin hnh sy nha tch loi nc v hm lng phenol t do cn litrong nha. Sy trong mi trng chn khng p=350 410 mmHg nhng trc khi htchn khng phi tin hnh lm lnh hn hp nha xung 75 78oC.

Sau khi sy tnh cht ca nha phi m bo cc ch tiu sau:- Nha c mu vng rm hoc vng hi nu- Nhit nh git : 95 105oC- nht dung dch 50% trong ru C2H5OH: 75 160Cp- Hm lng phenol t do < 9%Trong qu trnh sy giai on cui dng chng ct bng hi nc qu nhit nhmmc ch gim hm lng phenol t do trong nha.


50/79


51/79

- Cht lm trn, bng (stearat Zn, Ca...) 0,7 PKL- Cht trng rn (CaO, MgO...) 0,9 PKL- Cht mu (ch l mu sm) 4 4,5 PKL* Chun b nguyn liu:Nghin mn nha Novolac

Nghin mn v sng bt g ( 960 l/1cm2)* Tin hnh:- Trn 1 t nha nghin mn vi urotropin (m nh)- Trn 1 t nha nghin mn vi cht mu v cc ho cht khc- Trn nha v ph gia (ph gia c cho vo t t). Sau cho hn hp cht ng rnv hn hp cht mu chun btrn vo. u tin trn trong my hai trc nm ngangc cnh khuy hnh ch Z, tip tc trn trn my cn nng 2 trc c t tc nhit

rezitol -> rezit.+ Nha novolac kt hp vi urotropin to rezol -> rezitol -> rezit

- CH2 O CH2 - - CH2 - + CH2O(CH2)6N4 - CH2 - + 2 N2 (NH3)

+ Nha ng rn c mng li khng gian tng i dy c nn sn phm hidn, v vy khi thm ph gia vo th gim c tnh dn ca nha.

+ Khi qu trnh ng rn kt thc th trong cu to ca nha vn cn mt s nhmCH2OH t do hay ti nhn phenol vn cn v tr hot ng.


52/79

OH

CH2

OH

CH2OH

CH2

OH

CH2

OH

CH2

CH2

OH

CH2

CH2

OH

CH2OH

OH

CH2

CH2

OHOH

CH2

OH

CH2OH

CH2

+ CaO ngoi tc dng trng rn cn tham gia vo qu trnh phn ng nh:

O

Ca

O

* Tnh cht ca sn phm p:

+ Khi lng ring d = 1,25 1,4 g/cm3+ Gii hn bn ko k= 400 600 KG/cm

2

+ Gii hn bn nn n= 1000 1600 KG/cm2

+ dn di %= 0,3 0,7%+ cng Brinel 25 40 KG/mm+ ht nc tng 0,2 0,6%

+ bn ho hc: bn axit (tr axit c tnh oxi ha mnh), dung dch mui v ccho cht, khng bn vi kim (do c OH- ca phenol)IV/ Tnh cht, ng dng ca nha phenol-formaldehyt* Tnh cht :

Nha rezolic l mt hn hp sn phm phn t thng v nhnh, trng lng phn

t t 400 1000. Nha rezolic c tnh n nh cao, cha t phenol t do, bn ha hc v

cch in cao .


53/79

Nha rezolic nhit thng vn mt tnh chy nht, nng chy v ha tan,

ngha l khi bo qun tnh cht ca chng thay i theo chiu hng to thnh polimer

mng li v rezolic chuyn dn sang trng thi rezitol. Hm lng phenol t do cao hoc

thp cn ph thuc vo t l ca cc cu t, c im v lng xc tc, chiu su ngng

t v thi gian sy.Nha rezolic rn thng cha 812% phenol t do, nha rezolic lng cha 20

hoc cao hn. Lng phenol t do nhiu n s lm gim tc ng rn v tnh cht c

l ca sn phm. Nhng c mt s trng hp cn cha mt t phenol t do trong nha v

n lm cho nha d nng chy hn v to mng sau khi ng rn c n hi hn .

Hm lng oxy trong nha rezolic (khi iu ch dng xc tc NaOH) c mt s

lin kt ete( -CH2-O-CH2-)v khi un nng nha th thy c CH2O ta ra. Trong trng

hp dng xc tc NH4OH khng c lin kt ete v un nng nha n 200oC th khng

thy CH2O to ra.

Nha rezolic c th ha tan hon ton trong nhiu dung mi nh: xilohexanol,

phenol, dioxan, butanol... nhng vi iu kin l nhit si ca dung mi trn 100OC

lc th cc ni ngang u b ph hy.

Tc tng nhit nh hng n ha tan ca rezolic .Nu tng nhit

nhanh th lc nha cha k p trng trong dung mi, lng ni ngang tng ln v

ngng hn qu trnh ha tan nha. Nu un nng lu th c th lm rezolic tan hon ton.

Nha rezolic bng rn (rezit) : trong giai on rezit mng li tham gia to ra

khng nhng ch do lin kt ha hc m cn do lin kt l hc. nhit cao lin kt l

hc b ph hy do xut hin mt t tnh n hi, khi lm lnh tnh n hi mt i.

Trong nhng iu kin xc nh (nhit cao v un nng lu) nu dng mt

lng phenol tha x l rezit nghin nh th nha ny c th bin thnh nha

novolac trong trng hp ny xy ra hin tng t lin kt ha hc gia cc phn t v

to ra lin kt vi phenol.

*ng dng ca nha rezolic:

Nha rezolic lng (khng c nc) p dng rng ri tm vi, si, dng lm bt

p, dng lm vt liu p tng, keo dn v sn.

+Bt p :


54/79

Vt liu p dng bt l hn hp cu t phc t p ch yu t nha novolac v

rezolic .Bt p dng lm dng c k thut v sinh hot, dng lm vt liu cch in, chu

tc dng ca dng in 20kV to =200oC.

+Vt liu p tng:

Tectolit l cht do lp, c dng ch to t ca nhng tm vi c tm nharezolic, vi dng c th l vi thy tinh, vi dt cho, vi tng hp.

Tnh cht ca Tectolit: C bn nn, va p cao nhng km bn nc, chu xng

du tt nn dng trong cng nghip ch to my.

+ Keo dn v sn:

Nha phenol - formaldehyt c ngha quan trng dng sn xut keo dn v

sn. Keo phenol - formaldehyt c bn mi ni cao, chu m v vi khun nhng c

nhc im l mng dn gin. Nha phenol - formaldehyt l loi nha tng hp dng

sn xut sn. Ngoi nha v ru cn thm 5 10% colophan vo sn.

Sn du cao cp iu ch t nha 100%. Sn du Copan l loi sn c iu ch

t Copan trn vi du lanh nhit cao t 230 280oC. Sn t nha rezolic tan tt

trong cn. Ngoi ra nha rezolic cn dng lm cht dobt.


55/79

CHNG VIII: SN XUT NHA URE-FORMALDEHYTI/ Nguyn liu1/ Ure CO(NH2)2

d = 1,335 g/cm3tnc= 132,7

oC

+ Cu trc tinh th hnh kim di khng mu hoc hnh lng knh trng. Ure ho tantt trong nc, trong ru v trong amoniac lng, nhng ho tan t trong este v khngtan trong cloroform. Ure c c tnh kim yu v khi t nng dung dch nc ca uren 80oC to ra mui amon ca axit cacbamit NH3COOH, khi t cao hn 130

oC ure bphn hu thnh CO2 v NH3.

+ iu ch: NH3 tc dng vi CO2 to thnh cacbamat amon, sau tch nc tcacbamat rn hoc dng chy lng bng cch un nng n nhit 135 150oC v psut 55 60atm trong autoclave

CO2 + 2NH3 NH2COONH4 CO(NH2)2 + H2O2/ Formaldehyt ( CH2O) phn trc

II/ L thuyt trng ngng ure vi formaldehyt v cu to ca nha1/Qu trnh to ra cc sn phm ban u

Nhiu kin cho rng mono v dimetylol ure l nhng sn phm u tin ca phnng ure vi formaldehyt. Ph thuc vo cc iu kin sau:

+ T l xc nh gia ure v formaldehyt+ Mi trng trung tnh hoc kim yu+ Nhit phn ng thp

Trong mi trng kim yu pH = 7,5 8 v t l ure : formaldehyt = 1 : 1,6 2 thban u to ra monometylol v dimetylol ure.

O CNH

2

NH2

CH2O CO

NH

NH2

CH2OH

+

monometylol ure (tinh th)

O CNH

2

NH2

CH2O CO

NH

NH CH2OH

CH2OH

+

Dimetylol ure (tinh th)

Monometylol ure c nhit nng chy tnc=111 113oC, cn dimetylol ure

khong 121 122oC, chng tan tt trong nc, trong ru metylic, etylic, khng tan trongete.

Trong mi trng axit pH = 1 5 vi t l ure:formaldehyt = 1 : 2 hoc 1 : 1 th tora sn phm v nh hnh khng trong sut, khng tan.

to

2to


56/79

N CH2

CO

NH2

N CH2

CO

N CH2

monometylen ure dimetylen ure2/ Qu trnh to nha v cu to ca nha ure-formaldehyt

T monometylol ure to ra nha mch thng qu trnh xy ra theo tng bcNH CH

2OH

CO

NH2

NH2

CO

NH2

CH2

OH NH CH2OH

CO

NH CH2

NH CO NH2

OH2

NH CH2OH

CO

NH CH2

O CH2

NH

NH CH2OH

CO OH2

+ +

+

Tng qut:H2N-CO-NH-CH2-[-NH-CO-NH-CH2-]n-NH-CO-NH-CH2OH

T dimetylol ure c th to ra nha mch thng v vng

CH2

n

NCH

2OH

NH CH2OH

CO

NH CH2OH

OH2

HOCH2 NH CO NH CO NH CH

2 ` CO NH CH2OHN

CH2OH

+ Hoc:

N CH2

CO

NH CH2

N

NH

CO

CH2OH

CH2

N

n

CH

2N CH2

N CH2

CO

NH

CO

CH2OH

N CH2OH

N CH2

CO

NH

CO

CH2OH

CH2

N

3/ Qu trnh ng rnng rn nha UF ch xy ra trong trng hp nha cha cc nhm metylol t do.

Lng nhm metylol trong nha cng ln nu lng CH2O ly dng cho phn ng cngnhiu. Nhit v xc tc c nh hng n tc ng rn ca nha.

Cht xc tc ng rn nha ure-formaldehyt l cc axit hu c (axit oxalic, axitleic, axit formic....) axit v c(HCl, H3PO4...) mt s mui (clorua amn, clorua km...).III/ Sn xut nha ure-formaldehyt

Hoc

(n+2)


57/79

T l ure/formaldehyt = 1/1,6 2, pH = 7,5 8 (dng dung dch xt nng C%=10% trung ho). Cho axit oxalic hoc axit formic cui qu trnh 0,01 0,02

phn so vi ureTh t cho vo: cho formaldehyt vo thit b phn ng ri dng dung dch NaOH

10% khmg ch pH=7,5 8 sau cho ure vo tin hnh khuy trn. Nhit ban u

ca phn ng 40 50oC, trong giai on ny to dn xut mono nn khng nng nhitcao, duy tr nhit ny trong vng 30 45pht. Sau tng nhit ln 80 85oCtrong thi gian 20 pht v bo m pH khng thay i.

Lm ngui xung 60 65oC, cho thm dung dch axit oxalic nng 10 15%vo nhm mc ch to nha phn t ln hn v xc tc ng rn. Tng thi gian phnng 4 5 gi/1m.* Sn xut bt p ure-formaldehytThnh phn:

+ Nha (dung dch keo trong nc): 45 PKL+ Sunfit-xenlulo: 55 PKL+ Cht lm trn: 0,8% so vi nha+ Cht xc tc ng rn ( cc mui c tnh axit nh ZnCl2, NH4Cl hoc mui

sunfua axit)+ Cht mu (mu sng)Qu trnh phi trn tng t nh qu trnh chun b bt p phenol-formaldehyt

nhng phi ch nhit v thi gian. Tin hnh sy nhit thp v trong mi trngchn khng. S dng my nghin bi pha ngoi my phi c b phn lm lnh bng nc.

* iu kin p:p sut p: 250 280 KG/cm2

Nhit p: 135 145oCThi gian p: 70 110 giy/1mm chiu dy sn phmTrong qu trnh ng rn c to ra nc

Nhn xt: Mng li khng gian tha, cn mt lng nh nhm CH2OH- v NH2 t do.+ Nha bt p ure-formaldehyt

bn nhit cao nhng km bn vi nc c bit l nc nngKhi lng ring d = 1,35 1,45 g/cm3ko = 350 500 KG/cm

2nn = 1200 1500 KG/cm

2

u = 600 900 KG/cm2

bn nhit (Martens) 100 120oC ht m (25oC, thi gian 3 ngy m) 1 1,5%

IV/ Tnh cht v ng dng ca ure-formaldehyt.


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Nha ure c ng dng rng ri sn xut vt liu p, cht do lp, cht dobt, keo dn, mng ph...

- Vt phm t bt p ure formaldehyt dng lm cc dng cin ( chp n,cng tc, cu dao...), chi tit my in thoi, v my thu thanh, hng tiu dng (chu, cco, vn p...). un nng nhanh th vt phm t nha ure formaldehyt chu nhit 100

118oC, nu un lu th chu c nhit di 75oC.- Cht do lp dng lm bn, trang hong phng, bung li my bay, tu thu,

toa tu ho, dng c m nhc...- Cht do bt mipo l loi vt liu nh cch nhit, cch m ch yu i t nha ure

formaldehyt. u im cbn ca mipo l nh, dn nhit khng ln vo khng chynu thm photphat amon vo. Mipo c c im rt qu l ht th m thanh mnh, c

bit t tn s trung bnh n cao nn dng n truyn m rt tt khi xy dng nh ht,rp chiu bng...

- Keo t ure formaldehyt c s dng nhiu trong cng nghip sn xut vn p, ckhi dng lm keo dn snh s, kim loi

- Nha ure formaldehyt khng tan trong ru v du, sau khi ng rn th nnh trong dung dch km v chu nc khng m bo. Do tnh a nc ca nha nnmng nha to ra d b mv nt ng thi khng t do cn thit. V vy mun sdng nha ure formaldehyt lm sn th phi bin tnh nha.


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CHNG IX: SN XUT NHA MELAMIN-FORMALDEHYTI/ Nguyn liu:1/ Melamin: (2,4,6 triamino-1,3,5 triasin)

dng tinh th melamin l bt tinh th mu trng, c tnh kim yu nhng mnhhn ure, tan trong amoniac lng v dung dch NaOH, KOH, tan km trong nc v dung

mi hu c. Melamin c cng thc cu to c biu din nh sau:

NCC

N

NH2

NC

NH2

NH2

2/ Formaldehyt: xem phn trcII/ L thuyt a tmelamin vi formaldehyt

Thng thng th t l gia melamin v formaldehyt l: 1/ 2,8 1/3 c dng

lm bt p, cn nu 1/3 1/4 dng lm sn.iu kin phn ng: phn ng thc hin trong mi trng trung tnh hoc kim

yu pH = 7,5 8 v nhit t 90 98oC.

Cch phn ng: tng t nh ure-formaldehyt hay phenol-formaldehyt ban uto ra cc dn xut metylol melamin sau cc dn xut ny lin kt li vi nhau tora sn phm nha melamin-formaldehyt.

t l R

NH2

R NH2

NH2

CH2O

OH-,toNH

2R NH

2

NH CH2OH

NH R NH2

NH CH2OH

HOCH2

NH R NH

NH CH2OH

HOCH2

CH2OH

+

Nu tip tc un nng mnh hn th to ra:

NH2

R NH CH2OH

NH2

NH2

R NH

NH CH2

OH

CH2OH NH2 R NH CH2OH

NH2

OH-,to

NH2

R NH CH2

NH2

NH R NH

NH CH2OH

CH2

NH R NH

NH CH2OH

+ +

NCC

NNC


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Nhng nhm CH2OH t do v NH2 t do c kh nng tham gia phn ng tiptc thc hin qu trnh ng rn to thnh mng li khng gian dy c trong mi

trng axit v nhit 130 150oC.

NH R NH CH2

NH

NH R NH

NH CH2

CH2

NH R NH

NH

CH2

CH2

NH R NH CH2

NH R NH CH2

NH R

NH CH2OH

NH NH

NHCH2

Do melamin c nhiu nhm inh chc hn nn trong nha c nhiu ni ngang. V

vy nha melamin-formaldehyt c chu nc, chu nhit, cng v bng hn so vinha ure-formaldehyt.

III/ Sn xut nha melamin-formaldehyt

Cho formaldehyt vo thit b phn ng, iu chnh pH cho n khi pH = 7,5 8.Sau ta cho melamin vo ng thi tin hnh khuy trn, lc ny ta thu c hn hp

huyn ph ng nht. Tin hnh gia nhit n nhit 75 80oC do phn ng ta nhit

nn hn hp s t nng ln 90 98oC. Ginhit ny trong khong thi gian 40 60pht ta thu c nha nh tng trong nc.

Khi mun tch nc th h nhit xung v nc s tch thnh lp pha trnhn hp cn li vn l nh tng nhng nht cao hn.* Qu trnh sn xut bt p tng t nh PF v UFTnh cht ca bt p:

+ Khi lng ring d = 1,45 1,55 g/cm3

+ Gii hn bn ko k 620 750 KG/cm2

+ Gii hn bn nn u 650 KG/cm2

+ ht m (3 ngy m 25oC) = 0,1 0,15%+ bn nhit (Martens) > 120oC

IV/ Tnh cht v ng dng ca nha melamin-formaldehytCng nh nha ure formaldehyt, nha melamin formaldehyt dng sn xut bt

p, cht do tm, keo dn- Vt liu p c sn xut khng nhng t nha melamin formaldehyt n cn t

nha melamin ure formaldehyt. iu ch nha c n hi cao ta thm vo ccpolymer khc nh: polyamid, phenol formaldehyt, polyvinyl butyral


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- Nha tm melamin c bit l nha tm t vi thy tinh v vi thu tinh c gi trrt ln v mt k thut v n rt bn. Nha tm melamin t vi xenlulo v giy dng sn xut vt liu trang hong ( bc tng nh, lm mt bn gh), vt liu xy dng.

- Keo t nha melamin formaldehyt c dng nhiu trong ngnh g. So vi midn t nha ure formaldehyt th mi dn t nha melamin formaldehyt c kh nng chu

nc si trong thi gian di v gi thnh cng t hn keo ure formaldehyt.- Nha melamin formaldehyt khng bin tnh th khng trn vi cc cu t khc

trong sn c. n c th tan vo trong cc dung mi hu cv trn tt vi cc loinha khc th phi bin tnh nha. Khc vi nha ure formaldehyt bin tnh nha ny c bn nc v bn kh quyn cao, trn tt vi nha polyester, mng sn chu tc dngca cc cht n mn, chu nhit v bn mu, tnh cht in mi tt. Sn l sn phm trndung dch nha ete ho vi dung dch nha polyester trong du thu du v sau khi sy120oC th mng sn c bn cao v bng


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CHNG X: SN XUT NHA EPOXYI/Nguyn liu:

1/ Difenylonlpropan (hay 4,4- dioxy aiphenyl propan hay tn thng mi l bisphenol-A, dian )

HO CCH

3

CH3

OH

iu ch:-Bisphenol-A iu ch bng cch cho phenol tc dng vi axeton trong mi tng axitmnh nhit 40-50oC. Axit thng dng l H2SO4, HCl. Thi gian phn ng khong15-20h.

OH CH3 C CH3

O

HO C

CH3

CH3

OH OH2+ +

-Bisphenol-A c Tnc =155

oC, cu trc tinh th mu trng c th lm bng da, khng tantrong nc.

2> Epiclohidrin.

iu ch:

CH2

CH

Cl O

CH2

-i t glyxeryl

u tin cho hai kh HCl tc dng vi glixerin nhit 110-115oC trong mi

trng axit c c un nng.CH

2CH

OHOH

CH2

OH

ClH CH2 CH

ClCl

CH2

OH

+

Diclohydrin glyxerylSau cho xt c c un nng vo

CH2

CH

ClCl

CH2

OH

NaOH CH2

CH

Cl O

CH2 NaCl OH2+ + +

-i t propylene:

Clo ho propylen p sut 18 kg/cm2 v nhit 800oC to ra clorua allil, sau cho clohydrin tc dng ln ni i v cui cng dng kim kh HCl ca iclohydrinto ra piclohydrin.

CH2 = CH CH3 + Cl2 CH2 = CH CH2 Cl + HCl

2Xt to

CH3COOH

to

to

800oC, 18at

CH2 = CH CH2 Cl + HOCl


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CH2

CH

OHCl

CH2

Cl CH

2CH

OHCl

CH2

Cl

NaOH CH2

CH

Cl O

CH2

NaCl OH2+ + +

Epiclohydrin l mt cht lng khng mu, khng tan trong nc nhng tan trongcc dung mi hu c (C6H6, xeton,). Nhit si ts=118oC, d20

oC ( g/cm

3 ) = 1,175-1,180.II/ L thuyt to nha epoxy:

1>Phn ng a t nha epoxyNu tha piclohidrin th c th thu c te diglixit dioxi difenyl propan. phn ng xyra trong mi trng NaOH:

CH2

CH

Cl O

CH2 HO C

CH3

CH3

OHNaOH

CH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

O

CH2

NaCl OH2

+

+ +

Cch:+piclohidrin theo nhm epoxy tc dng vi hydro ca dioxydifenyl propan:

CH2 CHCl O

CH2 HO CCH

3

CH3

OH

CH2

CH

Cl OH

C

CH3

CH3

O CH2

CH CH2Cl

OH

CH2

O

+

+To ra nhm epoxy mi do t HCl:

CH2

CH

Cl OH

C

CH3

CH3

O CH2

CH CH2Cl

OH

CH2

ONaOH

CH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

O

CH2 NaCl OH2+ +

+Cc sn phm ban u tip tc ngng t vi ioxdifenil propan:

2 2

2 2


64/79

CH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

O

CH2 HO OHC

CH3

CH3

NaOHCH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

OH

CH2

O OHC

CH3

CH3

+

Cng thc tng qut:

CH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

OH n

CH2

O OC

CH3

CH3

CH2 CH2CH

O

Ta thy nha epoxy trng thi khng ng rn l nhng mch polyete di, trong nhm hydroxyl t do nm cch nhau mt khong cch tng i xa. Hai u mch lnhm epoxy. Nhm epoxy v hydroxyl c kh nng phn ng vi nhiu cht v ph thuc

vo nh chc ca cc chc m c th thu c hoc nha nhit do bin tnh hocnha ng rn khng nng chy v khng tan.Qu trnh xy ra chu nh hng ca t l cu t:

T l mol E/D T l molNaOH/E

Mp ng lngepoxy

Nhit mm,oC

2 1,1 451 314 43

1,4 1,3 791 592 84

1,25 1,3 1133 862 100

1,2 1,3 1420 1176 112T l E/D cng thp th KLPT cng cao, ng lng epoxy cng tng, nhit

mm tng. Cho xt t t, 2-3 ln bi v -Cl c th b thu phn trong mi trng kim tothnh OH lm bin i nguyn liu ban u.

III/ Cchmg rn nha epoxy1/ ng rn bng amin

-Thng thng ngi ta dng di hoc tri hoc polyamin, khng dng monoamin v skhng to mng li khng gian.-Cc cht ng rn thng dng nht l: etylen diamin (ng rn ngui hoc di 60oC ),dietylen diamin, dietylen triamin (ng rn nhit cao ), trietylen triamin c tc dnggn ging vi polyamin.-Phn ng ng rn:


65/79

CH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

OH n

CH2

O OC

CH3

CH3

CH2 CH2CH

O

NH2

R1" NH2

CH

O

CH2 CH2 O C

CH3

CH3

O CH2 CH

OH n

CH2 O OC

CH3

CH3

CH2 CH2NHCH

OH

R1" NH2

+

NH2 t do cn li tip tc tn cng vo u epoxy ca mch diepoxy khc lm ko dimch-Cc phn ng ph xy ra: nhit cao nhm OH phn ng vi u NH2 ca cht ng rn amin.

CH

OH

NH2

R1"NH2

CH

NH

R1"

NH2

OH2

++

Hoc nhit cao nhm OH phn ng vi u epoxy ca mch:

CH

OH

CH

O

CH2 CH2 O C

CH3

CH3

O CH

OH

CH2

CH

O

CH2 O C

CH3

CH3

O

+

+u im : cht ng rn ny c thng rn cc chi tit ln hoc dn gch p tng.+Nhc im : amin c v kh iu chnh thi gian chun b .

1>ng rn bng axit hai chc: (cht ng rn nng ), ng rn bng anhidric.-Thng dng l cc anhidric ca axit dicacboxilic, anhidric malic, anhidric phetalic-Phn ng ng rn vi axit hai chc:

CH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

OH n

CH

2O OC

CH3

CH3

CH2 CH2CH

O

HOOC R2 COOH

CH

O

CH2 CH2 O C

CH3

CH3

O CH2

CH

OH n

CH

2O OC

CH3

CH3

CH2 CH2 OOCCH

OHR2"COOH

+

V xy ra phn ng ng rn khc. To ra sn phm ph l nc khc vi loi cht

ng rn amin, nc to ra bay hi li l xp nn cht ng rn axit t dng-Phn ng ng rn vi anhidric

140-180oC


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V d: anhidric phtalicPhn ng tin hnh nhit cao t 180-220oC v qua cc giai on sau:Trc tin:

CH

OH

CO

CO

OCH

O

CO

COOH

+

Sau :

CH

O

CO

COOH

CH2 CH

O

CH

O

CO

COO CH2

CH

OH

+

2/ ng rn bng nhng cht ng rn khc-Ngoi hai cht ng rn trn ta cn dng cc hp cht c hai hay nhiu nhm nh chcd ng rn nha epoxy nh: nha phenol-formaldehyl, polyamine (-NH-CO-) ,ure(melamin)-formaldehyl.-ng rn bng hai cht ng rn trn th nha sau ng rn c nhiu vng thm trong

mch, c cng lm tng bn chc, bn nhit , trong nha c lin kt ete, este lmcho mch mm, trong nha c nhm OH t do to nn bm dnh tt, trong nha c s linkt ngang khng nhiu ( khng qu tha nh UF) lm mch khng qu cng.Do nha epoxy va bn nhit , bn chc, bm dnh tt vi hu ht cc vt liu khc.

IV/ Sn xut nha epoxy1/ Sn xut nha epoxy phn t thp:(M=370-600 vC)Sn xut to ra c hai loi : ED-5: ti a 500 vC;

ED-6: ti a 600 vC hoc tng tT l mol: Dian 1

Epi 2NaOH 2 (dung dch 15% )

u tin nhit thng cho epiclohidrin vo TB phn ng, ri cho dian vokhuy u vi s vng 300 vng/pht, to huyn ph ng nht. Sau cho 65% lngNaOH vo, un nng 60-65oC, gi trong mt gi. Chop tip 22% lng NaOH vo nngnhit ln 65-70oC gi trong 2 gi. Cui cng cho ht 13% lng NaOH cn li , nngnhit ln 70-75oC gi

7299721 Kt San Xuat Chat Deo

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