Chemical Modification of Poly(vinyl chloroformate) by Phenol Using

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Chapter 3

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Chemical Modification of Poly(vinyl chloroformate) by Phenol Using Phase-Transfer Catalysis 1

S. Boivin, P. Hemery, and S. Boileau

College de France, 11 Place Marcelin Berthelot, 75231 Paris Cédex 05, France

The nucleophilic substitution on poly(vinyl chloro­ formate) with phenol under phase transfer catalysis conditions has been studied. The C-NMR spectra of partly modified polymers have been examined in detail in the region of the tertiary carbon atoms of the main chain. The results have shown that the substitution reaction proceeds without degradation of the polymer and selectively with the chloroformate functions belonging to the different triads, isotactic sequences being the most reactive ones. 13

F u n c t i o n a l i z e d polymers have found i n c r e a s i n g use as s u p p o r t s , r e a g e n t s or c a t a l y s t s namely i n the f i e l d o f o r g a n i c s y n t h e s i s , m e t a l c h e l a t i o n o r pharmacology (J_). I t i s w e l l known t h a t c h e m i c a l m o d i f i c a t i o n o f polymers c o n t a i n i n g f u n c t i o n a l groups i s one o f t h e g e n e r a l r o u t e s f o r the s y n t h e s i s o f new p o l y m e r i c r e a g e n t s . I n the l a s t few y e a r s , the study o f the r e a c t i o n s o f the f u n c t i o n a l groups o f macromolecules has r e c e i v e d much a t t e n t i o n . K i n e t i c s and mechanisms of p o l y m e r - t r a n s f o r m a t i o n r e a c t i o n s depend on c h a r a c t e r i s t i c p o l y m e r i c e f f e c t s l i k e neighbouring-groups e f f e c t s as w e l l as c o n f i g u r a t i o n a l , c o n f o r m a t i o n a l , e l e c t r o s t a t i c o r super-molecular e f f e c t s . A t h e o r e t i c a l study s h o u l d take i n t o account a l l these e f f e c t s but i n p r a c t i c e the c o n s i d e r a t i o n o f even one o f them i s v e r y d i f f i c u l t . A mathematical treatment has been proposed by BOUCHER ( 2 ) and by PLATE and NOAH ( 3 ) . One o f t h e best known examples o f p o l y m e r - t r a n s f o r m a t i o n r e a c t i o n s i s the q u a t e r n i z a t i o n o f p o l y ( 4 - v i n y l p y r i d i n e ) by v a r i o u s a l k y l

Current address: Laboratoire de Chimie Macromoleculaire associe au Centre National de la Recherche Scientifique: U A 2 4 , Paris, France 0097-6156/88/0364-0037$06.00/0 © 1988 American Chemical Society

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

CHEMICAL REACTIONS ON POLYMERS

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38

and a r y l a l k y l h a l i d e s which y i e l d s a p o l y e l e c t r o l y t e . K i n e t i c s t u d i e s have been r e p o r t e d by s e v e r a l a u t h o r s ( 4 - 7 ) . They found r e t a r d a t i o n o f the r e a c t i o n which has been a t t r i b u t e d t o a dominant n e i g h b o u r i n g - g r o u p s e f f e c t w i t h t h e r e a c t i v i t y o f a p y r i d y l group m a i n l y due t o t h e s t e r i c h i n d r a n c e o f i t s m o d i f i e d n e i g h b o u r s . S i m i l a r n e i g h b o u r i n g - g r o u p s e f f e c t s as w e l l as e l e c t r o s t a t i c e f f e c t s have been observed i n the case o f n u c l e o p h i l i c s u b s t i t u t i o n o f p o l y ( m e t h y l m e t h a c r y l a t e ) w i t h o r g a n o l i t h i u m r e a g e n t s and t h e i r analogues ( 8 ) . Another well-known example o f p o l y m e r - t r a n s f o r m a t i o n r e a c t i o n i s the h y d r o l y s i s o f p o l y ( m e t h y l m e t h a c r y l a t e ) . K i n e t i c and m e c h a n i s t i c s t u d i e s c o r r e s p o n d i n g t o t h i s k i n d of r e a c t i o n have shown t h a t t h e r e a c t i v i t y o f e s t e r groups i s s e n s i t i v e t o r e a c t i o n c o n d i t i o n s , n e i g h b o u r i n g - g r o u p s e f f e c t s and t o polymer t a c t i c i t y ( 9 - 1 3 ) . Under b a s i c c o n d i t i o n s i t has been found t h a t s y n d i o t a c t i c sequences would be t h e most r e a c t i v e . Such c o n f i g u r a t i o n a l as w e l l as c o n f o r m a t i o n a l e f f e c t s have been a l s o r e p o r t e d by MILLAN e t a l . i n t h e case o f n u c l e o p h i l i c s u b s t i t u t i o n o f p o l y ( v i n y l c h l o r i d e ) w i t h sodium t h i o p h e n a t e ( 14 ) and w i t h sodium i s o o c t y l t h i o g l y c o l a t e o r i s o o c t y l t h i o s a l i c y l a t e ( 1 5 ) . The a u t h o r s have shown t h a t these r e a c t i o n s proceed s e l e c t i v e l y on t h e i s o t a c t i c TT d i a d s which can o n l y e x i s t e i t h e r i n t h e GTTG* i s o t a c t i c o r i n the TTTG h e t e r o t a c t i c t r i a d s , t h e former ones b e i n g much more r e a c t i v e than t h e l a t t e r ones. Nucleophilic substitution of chlorine i n poly(vinyl chloroformate) (PV0CC1) has been r e p o r t e d as one o f the b e s t procedure f o r the s y n t h e s i s o f new f u n c t i o n a l polymers (j_6). I t has been shown t h a t PV0CC1 can r e a c t w i t h n u c l e o p h i l i c compounds c o n t a i n i n g labile hydrogen atoms l i k e a l c o h o l s , phenols and amines (J_7). S i n c e i t i s p o s s i b l e t o prepare w e l l - d e f i n e d h i g h m o l e c u l a r weight PV0CC1 i n q u a n t i t a t i v e y i e l d s (J_8,J_9), c o n v e n i e n t c o n d i t i o n s have been found f o r the c h e m i c a l m o d i f i c a t i o n o f t h i s polymer w i t h e x c e l l e n t y i e l d s o f s u b s t i t u t i o n ( 2 0 ) . The b e s t r e s u l t s have been o b t a i n e d by u s i n g phase t r a n s f e r c a t a l y s i s (21-24). The u s e f u l n e s s o f t h i s t e c h n i q u e t o perform a g r e a t d e a l o f r e a c t i o n s i s now w e l l e s t a b l i s h e d i n o r g a n i c c h e m i s t r y (25-27). I n phase t r a n s f e r c a t a l y s i s a s u b s t r a t e i n an o r g a n i c phase i s r e a c t e d c h e m i c a l l y w i t h a reagent p r e s e n t i n another phase which i s u s u a l l y aqueous o r s o l i d . R e a c t i o n i s a c h i e v e d by means o f t h e t r a n s f e r agent; t h i s agent o r c a t a l y s t i s c a p a b l e o f s o l u b i l i z i n g o r e x t r a c t i n g i n o r g a n i c and o r g a n i c i o n s , i n the form o f i o n p a i r s , i n t o o r g a n i c media " (E.V. Dehmlow and S.S. Dehmlow ( 2 5 ) ) . I n the case o f the c h e m i c a l m o d i f i c a t i o n o f PV0CC1, two phases systems have been used : an o r g a n i c phase (PV0CC1 i n CH2CI2) and e i t h e r an aqueous phase (aq. 50% NaOH) o r a s o l i d phase (K2CO3 , potassium c a r b o x y l a t e ) w i t h a c a t a l y t i c amount o f BU4NHSO4 (TBAH), d i c y c l o h e x y l - l 8 - c r o w n - 6 o r c r y p t a n d [222]. These phase t r a n s f e r c a t a l y s i s c o n d i t i o n s a r e m i l d enough i n o r d e r t o a v o i d polymer d e g r a d a t i o n : they r e q u i r e l o w e r temperatures and s h o r t e r r e a c t i o n times than c l a s s i c a l c o n d i t i o n s . Furthermore, t h e a d d i t i o n o f a phase t r a n s f e r c a t a l y s t a l l o w s t o modify PV0CC1 w i t h a l k a l i n e s a l t s l i k e a l k a l i n e c a r b o x y l a t e s (22) o r w i t h u n s a t u r a t e d h e t e r o c y c l i c amines l i k e i n d o l e o r c a r b a z o l e (23,24). 11

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

3.

BOIVIN E T AL.

39

Phase-Transfer Catalysis

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Moreover i t has been shown t h a t PV0CC1 prepared by f r e e - r a d i c a l p o l y m e r i z a t i o n o f v i n y l c h l o r o f o r m a t e (V0CC1) i s an a t a c t i c polymer h a v i n g a B e r n o u i l l i a n s t a t i s t i c a l d i s t r i b u t i o n as expected ( J j ) ) . I n o r d e r t o extend our s t u d i e s on t h e c h e m i c a l m o d i f i c a t i o n o f PV0CC1, the s t e r e o s e l e c t i v e c h a r a c t e r o f t h e n u c l e o p h i l i c s u b s t i t u t i o n o f the c h l o r o f o r m a t e u n i t s w i t h phenol has been examined by t h e s t u d y o f the 13c-NMR s p e c t r a o f p a r t l y m o d i f i e d polymers i n t h e r e g i o n o f t h e a l i p h a t i c methine carbon atoms. The r e s u l t s o b t a i n e d i n t h i s f i e l d a r e p r e s e n t e d here.

EXPERIMENTAL

Polymer p r e p a r a t i o n . PV0CC1 sample has been prepared by f r e e - r a d i c a l p o l y m e r i z a t i o n o f pure V0CC1 ( a c q u i r e d from t h e SNPE, p u r i t y 99%) i n CH Cl2 a t 35°C u s i n g d i c y c l o h e x y l p e r o x y d i c a r b o n a t e as i n i t i a t o r . The e x p e r i m e n t a l procedure has been d e s c r i b e d p r e v i o u s l y (J_8,J_9) · The m o l e c u l a r weight M o f t h i s sample i s e q u a l t o 50,000. 2

P r e p a r a t i o n o f m o d i f i e d polymers. P h e n o l , BU4NHSO4 (TBAR), C H C 1 a r e commercial p r o d u c t s and they a r e used w i t h o u t s p e c i a l p u r i f i c a t i o n . The method f o r t h e c h e m i c a l m o d i f i c a t i o n o f PV0CC1 w i t h phenol has been d e s c r i b e d elsewhere (20,21). The degrees o f s u b s t i t u t i o n have been determined by e l e m e n t a l a n a l y s i s o f t h e r e m a i n i n g CI and C c o n t e n t s and by H NMR a c c o r d i n g t o the i n t e g r a t i o n o f the d i f f e r e n t peaks observed. The ^H-NMR s p e c t r a have been r e c o r d e d a t 60 MHz i n CD3COCD3 a t 27°C : ô(ppm/TMS) : ^CHar. : 7.1 ppm; -CH c h a i n : 5.2 ppm; -CH ~ c h a i n : 2.1 ppm. * 2

2

1

(

2

1

3c-NMR s p e c t r o s c o p y . The t a c t i c i t i e s f o r both s t a r t i n g and m o d i f i e d polymers have been determined from t h e 3c-NMR s p e c t r a r e c o r d e d a t 50.3 MHz, a t 20°C, w i t h a AM 200 SY Bruker s p e c t r o m e t e r . The polymers have been examined as a 10$ s o l u t i o n i n CD3COCD3 ( r e f : TMS). 1

1

RESULTS AND DISCUSSION

In a p r e v i o u s work i t has been found t h a t t h e c h e m i c a l m o d i f i c a t i o n o f PV0CC1 by phenol i n CH2CI2, by u s i n g p y r i d i n e as HC1 scavenger, l e a d s to a s o l u b l e polymer c o n t a i n i n g 88% o f v i n y l p h e n y l carbonate u n i t s (20). A b e t t e r y i e l d o f s u b s t i t u t i o n has been o b t a i n e d by u s i n g a liquid/liquid two phases system (50% aqueous NaOH/CH2Cl2) w i t h BU4NHSO4 as phase t r a n s f e r c a t a l y s t (21_,24) a c c o r d i n g t o t h e f o l l o w i n g r e a c t i o n scheme :

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

40

CHEMICAL REACTIONS ON POLYMERS

aq. 50% NaOH 00 Na

+

~CH -CH~ + Ô 0=0 Ô A 0

NBu^ X

^_

00 NBu^

+

-HNBUj.^X



00 NBu,"

+ A,CH -CH-~ 2

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2

ÇH Ç1 2

4

Na X

n

6

4

0=0 01

X" : C l " ; HS0 ~

2

4

Under such c o n d i t i o n s the s u b s t i t u t i o n r e a c t i o n o f PV0CC1 w i t h phenol i s q u i t e f a s t a t room temperature as shown by the r e s u l t s o f Table I . The degree o f s u b s t i t u t i o n reaches 84J a f t e r 15 min. (run 1) whereas the m o d i f i c a t i o n i s q u a n t i t a t i v e w i t h i n 45 min. under s i m i l a r c o n d i t i o n s (run 3 ) . Table I . Chemical m o d i f i c a t i o n o f PV0CC1 by phenol a t room temperature (PV0CC1 : 5 mmole; [Na0H]/[PV0CCl] = 2; [TBAH]/[PV0CC1] = 0.05)

Run

1 2 3 4 5 6 7

0OH (mmole)

CH C1 (ml)

5.1 5.0 5.1 5.1 0.7

50 50 50 50 35 40 45

1

2

4

'R 2.3

time (mn.)

2

15 25 45 120 20 35 30

^b) 84 91 100 98 14 29 46

a) D.S.(fl) -j-^c) 86

-

100 12 27 48

d

IH ^ _

-

100 14 29 44

a

^degree of s u b s t i t u t i o n b)determined by e l e m e n t a l a n a l y s i s o f the r e m a i n i n g C l and C. °)determined by H NMR. ) c a l c u l a t e d from the i n t e g r a t i o n o f the methine carbon peaks on 3c-NMR s p e c t r a . 1

d

1

R a t i o s [ c h l o r o f o r m a t e ] / [ p h e n o l ] h i g h e r than 1 have been used i n o r d e r t o prepare m o d i f i e d polymers w i t h a degree o f s u b s t i t u t i o n lower than 50% (runs 5-7, Table I ) . Under such c o n d i t i o n s i t can be n o t i c e d t h a t the s u b s t i t u t i o n r e a c t i o n s proceed q u a n t i t a t i v e l y w i t h r e s p e c t t o the i n i t i a l phenol c o n t e n t . The e v o l u t i o n o f the 3rj-NMR s p e c t r a o f m o d i f i e d polymers w i t h the degree o f s u b s t i t u t i o n , i n the r e g i o n o f the a l i p h a t i c methine carbon atoms, i s shown i n F i g u r e 1. Spectrum A c o r r e s p o n d i n g t o PV0CC1 p r e s e n t s t h r e e s i g n a l s l o c a t e d a t 78.9, 77.85 and 76.9 ppm which belong t o t e r t i a r y carbon atoms b e a r i n g c h l o r o f o r m a t e groups whereas the t h r e e s i g n a l s l o c a t e d a t 75.3, 73.6 and 72.0 ppm belong t o 1

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

Phase-Transfer Catalysis

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BOIVIN ET AL.

F i g u r e 1. C-NMR s p e c t r a o f m o d i f i e d PV0CC1 samples a t v a r i o u s c o n v e r s i o n s : A ( 0 ? ) ; Β ( 1 4 % ) ; C ( 2 9 ? ) ; D ( 4 6 ? ) ; Ε (100?).

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

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CHEMICAL REACTIONS ON POLYMERS

t e r t i a r y carbon atoms b e a r i n g carbonate groups. S p e c t r a B, C and D have been o b t a i n e d from p a r t l y m o d i f i e d polymers w i t h degrees o f s u b s t i t u t i o n e q u a l t o 14?, 29? and 46? r e s p e c t i v e l y (runs 5-7, Table I ) . I n the cases o f PV0CC1 and p o l y ( v i n y l phenyl carbonate) ( s p e c t r a A and Ε r e s p e c t i v e l y ) , t h e t e r t i a r y carbons o f t h e main c h a i n a r e s e n s i t i v e to t r i a d effects according to a B e r n o u i l l i a n s t a t i s t i c a l d i s t r i b u t i o n . Moreover, i n t h e case o f PV0CC1 (spectrum A ) , t h e m u l t i p l i c i t y o f t h e s i g n a l s shows t h a t t h e t e r t i a r y carbons o f t h e main c h a i n are l i k e l y s e n s i t i v e t o pentad e f f e c t s . The assignment o f the t h r e e main s i g n a l s t o i s o - , h e t e r o - and s y n d i o t a c t i c t r i a d s has been suggested p r e v i o u s l y f o r both PV0CC1 and p o l y ( v i n y l p h e n y l carbonate) ( 3 ) . I n t h e p r e s e n t work t h i s assignment has been c o n s i d e r e d t o be t r u e and i s i n d i c a t e d i n F i g u r e 1. I n t h e case o f p a r t l y m o d i f i e d polymers t h e s p e c t r a B, C and D show more c o m p l i c a t e d s t r u c t u r e s which can be presumably due t o s i g n i f i c a n t n e i g h b o u r i n g - g r o u p s e f f e c t s between phenyl carbonate groups and m o d i f i e d o r u n m o d i f i e d groups l i n k e d t o the next a l i p h a t i c methine carbon atoms. As shown i n Table I (runs 4-7) t h e degrees o f s u b s t i t u t i o n c a l c u l a t e d from the i n t e g r a t i o n o f t h e s i g n a l s c o r r e s p o n d i n g t o t h e methine carbons o f v i n y l c h l o r o f o r m a t e u n i t s and o f v i n y l phenyl carbonate u n i t s i n the m o d i f i e d polymers a r e i n good agreement w i t h the v a l u e s o b t a i n e d by e l e m e n t a l a n a l y s i s as w e l l as by 'H NMR. Such a r e s u l t a l l o w s t o compare the i n t e g r a t i o n s o f 3c-NMR s p e c t r a o f t h e s e polymers i n t h e r e g i o n o f t h e t e r t i a r y carbons o f t h e main c h a i n . The percentages o f t h e d i f f e r e n t t r i a d s b e a r i n g e i t h e r a c h l o r o f o r ­ mate o r a carbonate f u n c t i o n are r e p o r t e d i n Table I I . They have been c a l c u l a t e d from the i n t e g r a t i o n o f 3c-NMR s p e c t r a shown i n F i g u r e 1 . The sums o f the percentages ( i + i ' ) , (h+h') and ( s + s ) a r e independent o f the degree o f s u b s t i t u t i o n and a r e e q u a l t o t h e v a l u e s o f PV0CC1 ( i ) , ( h ) , ( s ) r e s p e c t i v e l y , w i t h i n the experimental e r r o r s . From these r e s u l t s i t i s r e a s o n a b l e t o c o n c l u d e t h a t no i n v e r s i o n i n the o r d e r o f the c h e m i c a l s h i f t s o f the t e r t i a r y carbon atoms b e l o n g i n g t o t h e d i f f e r e n t t r i a d s o c c u r s from t h e s t a r t i n g PV0CC1 t o t h e p o l y ( v i n y l phenyl c a r b o n a t e ) . Moreover t h e c h e m i c a l m o d i f i c a t i o n o f PV0CC1 by phenol does n o t induce any d e g r a d a t i o n o f the polymer. The degrees o f s u b s t i t u t i o n o f c h l o r o f o r m a t e f u n c t i o n s b e l o n g i n g t o i s o - , h e t e r o - and s y n d i o t a c t i c t r i a d s r e s p e c t i v e l y have been c a l c u l a t e d from t h e percentages shown i n Table I I . T h e i r e v o l u t i o n w i t h the t o t a l degree o f s u b s t i t u t i o n i s p l o t t e d i n F i g u r e 2. I t can be concluded t h a t t h e r e a c t i v i t y o f t h e c h l o r o f o r m a t e f u n c t i o n s decreases i n t h e f o l l o w i n g o r d e r : 1

1

f

i s o > hetero > syndio i n the f i r s t s t e p s o f s u b s t i t u t i o n (D.S. ^ 25?) . From the f o r e g o i n g i t c a n be suggested t h a t t h e c h l o r o f o r m a t e f u n c t i o n s b e l o n g i n g t o meso d i a d s are more r e a c t i v e than those b e l o n g i n g t o racemic d i a d s . A s i m i l a r r e s u l t has been observed p r e v i o u s l y by MILLAN e t a l . (J_4) i n the case o f t h e n u c l e o p h i l i c s u b s t i t u t i o n o f p o l y ( v i n y l c h l o r i d e ) w i t h sodium t h i o p h e n a t e .

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

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BOIVIN ET AL.

Phase- Transfer Catalysis

F i g u r e 2. Conversion o f c h l o r o f o r m a t e f u n c t i o n s c o r r e s p o n d i n g t o d i f f e r e n t t r i a d s ( i , h , s ) vs the degree o f s u b s t i t u t i o n o f the polymer.

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

44

CHEMICAL REACTIONS ON POLYMERS

Table I I .

Percentages of i s o - , hetero- and syndiotactic triads bearing either a chloroformate or a carbonate group i n PV0CC1 and i n the modified polymers ) a

H-C-0C0C1

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Run

b)

spectrum

(A) (B) (C) (D) (E)

PV0CC1 5 6 7 4 a

f

c)

6(ppm)

d)

78.9 i 0.25 0.19 0.16 0.11 0

H-Ç-OCO 0 2

77.85 h

76.9 s

75.3 i

73.6 h»

72.0 s

0.,48 0..41 0..34 0.,28 0

0..27 0..25 0..21 0..18 0

0 0.06 0.11 0.13 0.26

0 0.06 0.12 0.21 0.48

0 0.,02 0.,06 0., 10 0..26

f

1

f

) i+h+s+i +h +s'=1 ) see Table I. °)see F i g . 1. )Chemical s h i f t s of ~X-NMR signals corresponding to the a l i p h a t i c methine carbons of the main chain i n ppm/TMS. b

d

CONCLUSION

In conclusion the nucleophilic substitution of poly(vinyl chloroformate) with phenol by using a l i q u i d / l i q u i d two phases system (50% aqueous NaOH/CI^C^) with BU4NHSO4 as phase transfer catalyst proceeds both without degradation of the polymer and s e l e c t i v e l y with different triads. In order to explain why the chloroformate functions belonging to i s o t a c t i c sequences are the most reactive, further work i s presently undertaken concerning the study of the conformational structure of PV0CC1 macromolecules i n solution. Along the same l i n e , i t would be interesting to examine some substitution reactions of trimeric models having different stereoconfigurations. Moreover i t would be worth extending this preliminary study to the examination of the behaviour of PV0CC1 samples with different t a c t i c i t i e s .

REFERENCES 1. MATHUR,N.K.; NARANG,C.K.; WILLIAMS,R.Ε. Polymers as Aids in Organic Chemistry; Academic Press : New York, 1980; GECKELER,K.; PILLAI,V.N.R.; MUTTER,M. Adv. Polym. Sci. 1981, 39, 65; AKELAH,A.; SHERRINGTON,D.C. Chem. Rev. 1981, 81, 557; Polymer 1983, 24, 1369; FORD,W.T.; TOMOI,M. Adv. Polym. Sci. 1984, 55, 49. 2. BOUCHER,E.A. Prog. Polym. Sci. 1978, 6, 63. 3. PLATE,Ν.Α.; NOAH,O.V. Adv. Polym. Sci. 1979, 31, 133.

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

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3.

BOIVIN E T AL.

Phase-Transfer Catalysis

45

4. TSUCHIDA,E.; IRIE,S. J. Polym. Sci. Polym. Chem. Ed. 1973, 11, 789. 5. ΝΟΑΗ,Ο.V.; LITMANOVICH,A.D.; PLATE,N.A. J. Polym. Sci. Polym. Phys. Ed. 1974, 12, 1711. 6. MORCELLET-SAUVAGE,J.; LOUCHEUX,C. Makromol. Chem. 1975, 176, 315. 7. BOUCHER,E.A.; MOLLETT,C.C. J. Chem. Soc. Faraday Trans.1 1982, 78, 75; BOUCHER,E.A.; KHOSRAVIBABADI, E. J. Chem. Soc. Faraday Trans. 1 1983, 79, 1951. 8. BOURGUIGNON,J.J.; GALIN,J.J.; BELLISSENT,H.; GALIN,J.C. Polymer 1977, 18, 937; BOURGUIGNON,J.J.; GALIN,J.C. Polymer 1982, 23, 1493. 9. PLATE,N.A. Pure Appl. Chem. 1976, 46, 49. 10. DE LOECKER,W.; SMETS,G. J. Polym. Sci. 1959, 40, 203. 11. BAINES,F.C.; BEVINGTON,J.C. J. Polym. Sci. A-1 1968, 6, 2433. 12. KLESPER,E.; BARTH,V. Polymer 1976, 17, 777, 787. 13. BUGNER, D.E. Am. Chem. Soc. Polym. Prep. 1986, 27(2), 57. 14. MARTINEZ,G.; MIJANGOS,C.; MILLAN,J. J. Macromol. Sci. 1982, A-17, 1129; Polym. Bull. 1985, 13, 151; J.Polym. Sci. Polym. Chem. Ed. 1985, 23, 1077; MIJANGOS,C.; MARTINEZ,G.; MICHEL,Α.; MILLAN,J.; GUYOT,A. Eur. Polym. J. 1984, 20, 1. 15. MIJANGOS,C.; MARTINEZ,G.; MILLAN,J. Eur. Polym. J. 1986, 22, 423. 16. MEUNIER,G.; BOIVIN,S.; HEMERY,P.; SENET,J-P.; BOILEAU,S. in Modification of Polymers; CARRAHER,C.E.; MOORE,J.A. Plenum Press : New York, 1983; Vol.21, p.2293. 17. SCHAEFGEN,J.R. Am. Chem. Soc. Polym. Prep. 1967, 8(1), 723; J. Polym. Sci. 1968, C24, 75. 18. BOILEAU,S.; JOURNEAU,S.; MEUNIER,G. Fr. Patent 1980, 2 475 558. 19. MEUNIER,G.; HEMERY,P.; BOILEAU,S.; SENET,J-P.; CHERADAME,H. Polymer 1982, 23, 849. 20. MEUNIER,G.; BOIVIN,S.; HEMERY,P.; BOILEAU,S.; SENET,J-P. Polymer 1982, 23, 861. 21. BOIVIN,S.; CHETT0UF,A.; HEMERY,P.; BOILEAU,S. Polym. Bull. 1983, 9, 114. 22. BOIVIN,S.; HEMERY,P.; SENET,J-P.; BOILEAU,S. Bull. Soc. Chim. France 1984, II 201. 23. KASSIR,F.; BOIVIN,S.; BOILEAU,S.; CHERADAME,H.; WOODEN,G.P.; OLOFSON,R.A. Polymer 1985, 26, 443. 24. BOIVIN,S.; HEMERY,P.; BOILEAU,S. Can. J. Chem. 1985, 63, 1337. 25. WEBER,W.P.; GOKEL,G.W. Phase Transfer Catalysis in Organic Synthesis, Springer-Verlag : New York, 1978; STARKS,C.M.; LIOTTA,C. Phase Transfer Catalysis : Principles and Techniques, Academic Press : New York, 1978; DEHMLOW,E.V.; DEHMLOW,S.S. Phase Transfer Catalysis, Verlag Chemie : Weinheim, 1980. 26. ANTOINE, J.P.; DE AGUIRRE, I.; JANSSENS, F.; THYRION, F. Bull. Soc. Chim. France 1980, 5-6, II-207. 27. MONTANARI, F.; LANDINI, D.; ROLLA, F. Topics in Current Chemistry 1982, 101, 147. RECEIVED August 27, 1987

Benham and Kinstle; Chemical Reactions on Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1988.