Radical Polymerization of Vinyl Monomer with an Aqueous Solution of

8 V i n y l Polymerization (383): Radical Polymerization of V i n y l Monomer with an Aqueous Solution of

Downloaded by MICHIGAN STATE UNIV on February 19, 2015 | http://pubs.acs.org Publication Date: June 10, 1980 | doi: 10.1021/bk-1980-0121.ch008

Polystyrenesulfonate or Polyvinylphosphonate M. IMOTO, T. OUCHI, M. SAKAE, E. MORITA, and T. YAMADA Department of Applied Chemistry, Faculty of Engineering, Kansai University, Suita, Osaka 564, Japan In 1962, Kimura, Takitani and Imoto (1) found that an aqueous solution of starch could easily polymerize methyl methacrylate (MMA) and about a half of polymerized MMA grafted on starch. This novel polymerization was called as "uncatalyzed polymerization". Since then, a lot of macromolecule was applied, instead of starch, and many of them were effective to initiate the radical polymerization of MMA. Effective macromolecules were found to be divided into two groups. The macromolecules which belong to Group I are effective only in the presence of some metal ion, particularly Cu(II) ion. The macromolecules of Group II require no metal ion. They are listed in Tables 1 and 2. As can be seen, the effective macromolecules are water-soluble or at least somewhat hydrophilic. Strongly hydrophobic macromolecules and low molecular compounds were always ineffective. The ineffective substances which were tested are listed in Table 3. Table 1. Effective Macromolecular Substances: Group I (Effective in the presence of Cu(II) ion) Starch (1), Cellulose (2), Cellulose Methyl Ether (3), Oxy-cellulose (4), PVA (5), Partially Hydrolyzed PVAc (6), Silk (2), Wool (7), Hide-Powder (8), Natural Rubber Latex (9), Synthesized Poly-(a-Amino Acids) (10), Nylon-6 (11), Nylon-3 (12), a-Amylase (13), Lysozyme (14), RNA (15), Polyacrylonitrile (16), Polyvinylsulfonate (17) . Table 2. Effective Macromolecular Substances: Group II (Effective in the absence of Cu(II) ion) Polymethallylsulfonate (18), Polyallylsulfonate (19), Polystyrenesulfonate (20), Crosslinked Polystyrenesulfonate (Ion Exchange Resin) (21), Chondroitin Sulfate (22), Polyvinylphosphonate (23) .

0-8412-0540-X/80/47-121-103$05.00/0 © 1980 American Chemical Society In Modification of Polymers; Carraher, C., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1980.

MODIFICATION O F POLYMERS

104

T a b l e 3. I n e f f e c t i v e S u b s t a n c e s (24) Macromolecules: P o l y v i n y l c h l o r i d e , Polyethylene, Polypropylene, Styrene-Butadiene Rubber. Low m o l e c u l a r compounds: G l u c o s e , S u c r o s e , ATP, CH3CH S03Na, a-Amino A c i d , P o l y p h o s p h o n i c A c i d , e t c . 2


The p r e s e n t p a p e r d e a l s w i t h t h e u n c a t a l y z e d r a d i c a l p o l y m e r i z a t i o n i n i t i a t e d w i t h the w a t e r - s o l u b l e macromolecule i n the absence o f C u ( I I ) i o n . U s i n g p o l y s t y r e n e s u l f o n a t e (PSS-Na) and polyvinylphosphonate (PVPA) as t h e m a c r o m o l e c u l e s , a s t u d y on t h e p r o c e s s o f p o l y m e r i z a t i o n was made. And a new c o n c e p t on t h e " h a r d and s o f t h y d r o p h o b i c a r e a s and monomers" was p r o p o s e d . Experimental M a t e r i a l s : PSS-Na ( 2 0 ) was p r e p a r e d by t h e r a d i c a l p o l y m e r i zation of p-styrenesulfonate. PVPA was o b t a i n e d b y t h e h y d r o l y s i s o f p o l y - b i s - Q 3 - c h l o r o e t h y l ) v i n y l p h o s p h o n a t e and was c o n c l u d e d t o have a f o l l o w i n g formula ( 2 3 ) : Bu-- CH2-9H 0=P-0Na ONa

CH -£H 0=P-0Na 0-CH CH OH 2

16.81

2

2

•H CH -CH 0=P-0Na 4-CH CH Cl 7.0** 4.2 2

2

2

P r o c e d u r e s : V i n y l monomer and an aqueous s o l u t i o n o f t h e m a c r o m o l e c u l e w e r e p l a c e d i n a t u b e and s e a l e d u n d e r vacuum a f t e r thawing w i t h n i t r o g e n . The t u b e was s h a k e n o r a l l o w e d t o s t a n d a t 85°C. I n t h e c a s e o f s h a k i n g , t h e c o n t e n t s were p o u r e d i n t o methanol to p r e c i p i t a t e the polymer. I n the case o f s t a n d i n g , t h e u p p e r MMA p h a s e and t h e l o w e r w a t e r p h a s e w e r e p i p e t t e d o u t s e p a r a t e l y and poured i n t o methanol. I t was c o n f i r m e d by I R and e l e m e n t a l a n a l y s i s t h a t poly-MMA c o n t a i n e d n e i t h e r s u l f o n a t e group n o r p h o s p h o n a t e g r o u p . Theref o r e , any g r a f t e d c o p o l y m e r i z a t i o n o f MMA o n t o m a c r o m o l e c u l e was not observed. R e s u l t s and D i s c u s s i o n 1.

P o l y m e r i z a t i o n s b y PSS-Na and PVPA. We h a v e r e p e a t e d l y r e p o r t e d t h a t a c o e x i s t e n s e o f w a t e r i s indispensable f o r the uncatalyzed polymerization. Also i n the p r e s e n t c a s e s o f PVPA a n d PSS-Na, t h e p o l y m e r i z a t i o n o f MMA p r o c e e d e d o n l y i n t h e p r e s e n c e o f w a t e r , a s shown i n F i g . 1. F i g u r e 2 showed t h e e f f e c t o f t h e d i s s o l v e d mass o f PSS-Na o r PVPA on t h e r a t e o f p o l y m e r i z a t i o n o f MMA. When t h e mass o f PSS-Na o r PVPA was l e s s t h a n a c e r t a i n l i m i t , t h e r a t e o f p o l y m e r i z a t i o n o f MMA i n c r e a s e d w i t h t h e mass o f PSS-Na o r PVPA. However, p a s s i n g a c e r t a i n mass, t h e c o n v e r s i o n became t o d e c r e a s e o r t o b e i n d e p e n d e n t o f t h e mass o f f e e d e d

In Modification of Polymers; Carraher, C., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1980.


8.

IMOTO E T A L .

Figure 1.

Vinyl

Polymerization

105

Conversion of MMA vs. mass of H 0 (PSS-Na(P 450) or PVPA 0.1 g, MMA 3 cm ; 85°C, 3 hr, under shaking) 2

n

3

macromolecule. T h e s e r e s u l t s s u g g e s t e d t h a t when t h e c o n c e n t r a t i o n o f d i s s o l v e d m a c r o m o l e c u l e was h i g h , t h e m a c r o m o l e c u l e s e n t a n g l e d w i t h each o t h e r and became d i f f i c u l t t o f o r m t h e a d e q u a t e h y d r o p h o b i c a r e a s , i n t o w h i c h t h e monomer was i n c o r p o r a t e d . A c c o r d i n g l y , t h e c o n v e r s i o n o f MMA d e c r e a s e d , when t h e c o n c e n t r a t i o n o f m a c r o m o l e c u l e was t o o h i g h . The e f f e c t s o f t h e mass o f s t y r e n e ( S t ) a n d MMA o n p o l y m e r y i e l d s c a n be s e e n i n F i g s . 3 a n d 4. The c o n c e n t r a t i o n o f PVPA o r PSS-Na was k e p t c o n s t a n t a n d added mass o f S t o r MMA was v a r i e d .



106


Figure 3.

Conversion of styrene vs. mass of styrene (PSS-Na(P 5 cm ; 85°C, 3 hr. under shaking)

n

450) 0.1 g, H 0 2

3

(cm )

MMA

4 6 (cm )

2 Figure 4.

3

MMA

3

Conversion of MMA vs. mass of MMA (PSS-Na(P 450) 0.1 g, H 0 5 cm ; PVPA 0.1 g, H 010 cm ; 85°C, 3 hr, under shaking) n

3

2

2

3

By s u b s t r a c t i n g t h e t h e r m a l y i e l d f r o m t h e o v e r a l l y i e l d , t h e c o r r e c t e d y i e l d was c a l c u l a t e d . Beyond a c e r t a i n mass o f MMA o r S t , t h e y i e l d s became t o b e i n d e p e n d e n t o f t h e mass o f t h e monomer. This i s e x p l a i n e d by t h e f o l l o w i n g c o n s i d e r a t i o n : t h e f i r s t s t e p o f t h e p o l y m e r i z a t i o n i s t h e i n c o r p o r a t i o n o f monomer i n t o the hydrophobic areas. When a s u f f i c i e n t mass o f t h e monomer i s a d d e d , t h e a r e a s may be s a t u r a t e d w i t h t h e monomer. Thus, t h e e x c e s s o f t h e monomer becomes u s e l e s s .



8. IMOTO E T A L .

Vinyl

Polymerization

107

Figure 5. Application of MichaelisMent en-Line weaver-Burk's equation (PVPA 0.1 g, H 0 10 cm ; 85°C, 3 hr, P indicates the degree of polymerization of poly-MMA) 3

2

nc

S u c h a r e l a t i o n s h i p b e t w e e n t h e p o l y m e r y i e l d a n d t h e mass of f e e d e d MMA i s s i m i l a r t o t h a t i n t h e e n z y m a t i c r e a c t i o n . T h e r e f o r e , t h e r e s u l t was a p p l i e d t o M i c h a e l i s - M e n t e n e q u a t i o n a n d i n t h e c a s e o f PVPA, t h e r e s u l t shown i n F i g . 5 was o b t a i n e d . Such a good agreement w i t h t h e M i c h a e l i s - M e n t e n - L i n e w e a v e r - B u r k ' s e q u a t i o n was a l w a y s o b s e r v e d i n t h e u n c a t a l y z e d p o l y m e r i z a t i o n .

2.

C o n f i r m a t i o n o f the Formation o f Hydrophobic Areas. The d i r e c t e v i d e n c e o f t h e f o r m a t i o n o f h y d r o p h o b i c a r e a s (HA) was o b t a i n e d b y s c a n n i n g e l e c t r o n m i c r o s c o p y , c f . F i g s . 6 a n d 7. As m e n t i o n e d a b o v e , t h e p r e s e n c e o f w a t e r i s i n d i s p e n s a b l e . Now t h e r e a s o n i s c l e a r . Water i s n e c e s s a r y f o r t h e f o r m a t i o n o f HA i n w h i c h t h e p o l y m e r i z a t i o n s t a r t s . Figure 8 v e r i f i e d this conclusion. When DMSO was m i x e d , PVPA became d i f f i c u l t t o f o r m HA. T h u s , t h e p r o c e s s o f p o l y m e r i z a t i o n c o u l d be c o n c l u d e d t o be as f o l l o w s : ( i ) PVPA o r PSS-Na forms HA i n t h e aqueous p h a s e , ( i i ) V i n y l monomer i s i n c o r p o r a t e d i n t o t h e HA, ( i i i ) I n t h e HA, the p o l y m e r i z a t i o n s t a r t s . 3. E f f e c t o f t h e D e g r e e o f P o l y m e r i z a t i o n o f PSS-Na o n t h e V i n y l Polymerization. As T a b l e 4 showed, t h e c o n v e r s i o n s o f MMA and S t d e c r e a s e d w i t h t h e i n c r e a s e o f t h e d e g r e e o f p o l y m e r i z a t i o n ( P ) o f PSS-Na. T h i s was due t o t h e d i f f i c u l t y o f t h e f o r m a t i o n o f HA when t h e l a r g e PSS-Na was d i s s o l v e d i n s u c h a q u a n t i t y o f w a t e r . I n other w o r d s , when PSS-Na w i t h a l a r g e P w e r e d i s s o l v e d i n w a t e r , t h e m o l e c u l e s o f PSS-Na e n t a n g l e d w i t h e a c h o t h e r and became d i f f i c u l t to f o r m t h e a d e q u a t e HA. T h i s a s s u m p t i o n was v e r i f i e d by t h e n

n




Figure 6. Surface views of PVPA: (A) 0.1 g of PVPA was dissolved in 1 dm of H 0; (B) PVPA 0.01 g, H 0 1 cm , MMA 0.3 cm ; 85°C, 3 hr. After the polymerization the system was diluted with 100 cm of H 0 3

2

2

3

3

3

2

Figure 7. Surface views of PSS-Na (PSS-Na(P 450) 0.1 g, MMA 3 cm , H 0 5 cm , diluted to 0.5 dm ) (A) before polymerization; (B) after polymerization (85°C,3hr) n

3

3


3

2


8.

IMOTO E T A L .

0

Vinyl

Polymerization

0.5

Mole f r a c t i o n

109

Figure 8. Conversion of MMA vs. fraction of H 0 in the mixed solvent of H 0 and DMSO (MMA 3 cm , PVPA 0.1 g, (H 0 + DMSO) 10 cm ; 85°C, 3 hr)

i.o

2

of H 0 i n feed

2

3

2

3

2

Table 4 E f f e c t o f P o f PSS-Na on t h e V i n y l P o l y m e r i z a t i o n (PSS-Na 0.1 g, Monomer 3 c m , H 0 5 c m ; 85°C, 3 h ) n

3

3

2

PSS-Na

85 107 450 870 3090

Conversion [n]

MMA

AN

0.062 0.260 0.500 1.780

0.0 41.0 54.0 16.7 4.0 1.7

0 0 0 0 0 0

(%) St 0.0 20.0 3.8 6.4 3.1 1.8

Sodium e t h y l b e n z e n e s u l f o n a t e . M e a s u r e d i n 0.5 N - N a C l aqueous s o l u t i o n a t 30°C. s c a n n i n g e l e c t r o n m i c r o s c o p i c m e t h o d , u s i n g PSS-Na h a v i n g P o f 3090. As shown i n F i g . 9 ( A ) , when PSS-Na h a v i n g a P o f 3090 was d i s s o l v e d i n 500 cm3 o f w a t e r , t h e f i g u r e s w e r e a l i k e t o assembled fibers. I t i s c l e a r t h a t PSS-Na d i d n o t f o r m HA t o i n c o r p o r a t e t h e monomer. On t h e c o n t r a r y , when t h e same PSS-Na s o l u t i o n was d i l u t e d t o 5000 c m w i t h w a t e r , t h e commencement o f f o r m a t i o n o f HA was o b s e r v e d , a s shown i n F i g . 9 ( B ) . Accordingly, when v e r y d i l u t e d s o l u t i o n i s a p p l i e d , t h e p o l y m e r i z a t i o n s h o u l d be t a k e n p l a c e , e v e n i f P i s v e r y h i g h a s 3090. R

n

3

n




110

Figure 9. Surface views of PSS-Na(P 3090): (A) 0.1 g of PSS-Na(P 3090) dissolved in 5 cm of H 0, heated at 85° C for 3 hr, and diluted with 500 cm of H 0; (B) same sample as (A) diluted with 2500 cm of H 0 n

3

n

3

2

3

2

2

We c a r r i e d o u t t h e p o l y m e r i z a t i o n o f MMA. The r e s u l t s , w h i c h a g r e e d w e l l w i t h t h e e x p e c t a t i o n , w e r e o b t a i n e d , a s shown i n T a b l e 5. Table 5 E f f e c t o f D i l u t i o n o f t h e Aqueous PSS-Na S o l u t i o n on t h e P o l y m e r i z a t i o n o f MMA (MMA 3 c m ; 85°C, 3 h , u n d e r s h a k i n g ) 3

PSS-Na(P g

n

0.1 0.01 0.01 0.01 0.01

3090)

J*2° cmo

Conversion

5 5 10 15 20

1.7 1.7 1.8 2.8 6.3

Including the thermal conversion

%

o f 0.8 + 0.2 %.

4.

Hard and S o f t Hydrophobic A r e a s . F o l l o w i n g t o t h e concept o f h a r d and s o f t a c i d s and bases, we w o u l d l i k e t o p r o p o s e a c o n c e p t o f h a r d a n d s o f t HA ( m i c e l l e s ) and h a r d a n d s o f t monomers. The m i c e l l e s f o r m e d b y d o d e c y l b e n z e n e s u l f o n a t e (ABS) i n w a t e r


8.

IMOTO E T A L .

Vinyl

Polymerization

111

1 1

are c a l l e d t o be " h a r d , because t h e i n t e r i o r i s a l i k e t o an a s s e m b l e o f h y d r o c a r b o n m o l e c u l e s and s t r o n g l y h y d r o p h o b i c . Howe v e r , HA formed b y t h e w a t e r - s o l u b l e m a c r o m o l e c u l e s a r e n o t h y d r o phobic i n a s t r i c t meaning. I t i s r a t h e r a l i k e an agglomerate o f the macromolecules. T h u s , t h e i n t e r i o r s o f HA formed b y PSS-Na o r PVPA a r e n o t s o h y d r o p h o b i c , b u t r a t h e r somewhat h y d r o p h i l i c a n d c a l l e d t o be " s o f t " . The o r d e r o f h a r d n e s s o f HA may be a s follows:


S t a r c h , PVPA SO3 Na+ Soft

(PSS-Na)

S i m i l a r l y , v i n y l monomers c a n be p u t i n o r d e r f r o m h a r d t o s o f t monomer, a c c o r d i n g t o t h e i r h y d r o p h o b i c i t i e s . As a s c a l e o f h y d r o p h o b i c i t y o f v i n y l monomer, t h e s o l u b i l i t y i n w a t e r may be adopted. F i g u r e 10 showed some e x a m p l e s . S t y r e n e i s t h e most h a r d monomer a n d AN i s t h e most s o f t monomer. B u t y l a c r y l a t e and b u t y l m e t h a c r y l a t e a r e more h a r d b y one o r d e r t h a n m e t h y l o r e t h y l a c r y l a t e and m e t h a c r y l a t e . And t h e c o n c e p t i s r e a l i z e d a s f o l l o w s : A v i n y l monomer h a v i n g a c e r t a i n hardness o r s o f t n e s s f o r i t s h y d r o p h o b i c i t y c a n be i n c o r p o r a t e d t h e most e a s i l y i n t o t h e HA h a v i n g a c o r r e s p o n d i n g hardness or s o f t n e s s . The v a l i d i t y o f t h i s c o n c e p t c o u l d b e o b s e r v e d i n t h e f o l l o w ing experimental r e s u l t s .

Hard

t

0.1-

1-

->St*

->BMA**(1.0) ->BA* (1.4)

10 •MMA**(16), EA*(20)

i.

Soft 100 -

*AN*(74)

Figure 10. Solubilities of vinyl monomers at 20°C. Numbers indicate the solubilities of the monomers in water (g dm' ) (BA) butyl acrylate; (BMA) butyl methacrylate; (EA) ethyl acrylate; (MA) methyl acrylate. (*, 27); (**, 28) 3



112


5.

V e r i f i c a t i o n o f t h e C o n c e p t o f H a r d a n d S o f t HA a n d Monomers. (1) S e l e c t i v i t y o f V i n y l Monomer f o r t h e U n c a t a l y z e d P o l y merization. Among t h e m e t h a c r y l a t e s , m e t h y l and e t h y l e s t e r c a n be t h e most e a s i l y p o l y m e r i z e d by t h e u n c a t a l y z e d p o l y m e r i z a t i o n . This s p e c i f i c i t y was a c o n c l u s i o n (25) w h i c h was o b t a i n e d i n t h e u n catalyzed polymerization i n i t i a t e d with s i l k or cellulose. Also i n t h e c a s e s o f PVPA (23) a n d s t a r c h ( 2 6 ) t h e same s p e c i f i c i t y was o b s e r v e d , a s shown i n T a b l e 6. n - B u t y l e s t e r was a l w a y s h a r d l y polymerized. These s p e c i f i c p o l y m e r i z a b i l i t i e s o f MMA and e t h y l m e t h a c r y l a t e a r e n o t due t o t h e i r r e a c t i v i t i e s . According to l i t e r a t u r e ( 2 9 ) , t h e p r o p a g a t i n g and t e r m i n a t i n g r e a c t i o n c o n s t a n t s , k p and k t , a r e shown i n T a b l e 7. B u t y l e s t e r i s u s u a l l y more r e a c t i v e than methyl o r e t h y l e s t e r . Table 6 P o l y m e r i z a t i o n s o f V i n y l Monomers w i t h Watersoluble Macromolecules (PVPA, S t a r c h , P S S - N a ( P 1 0 0 0 ) , 0.1 g, H 0 10 cm3 (PVPA, S t a r c h ) 5 c m ( P S S - N a ) , Monomer 3 cm3, C u C l 2 - 2 H 0 0 g (PVPA, P S S - N a ) , 0.5 mg ( S t a r c h ) ; 85°C, 3 h , u n d e r s h a k i n g ) n

2

3

2

C o n v e r s i o n (%) Starch PVPA(23)

Monomer CH =C(CH )-COOR R=CH C H i-C H n-C4H CH =CH-C00R R=CH C H n-CZiHg 2

P S S - N a ( P 1000) n

3

5

3

6.0 5.3 2.2 1.2

4.1 5.5

3

2

7

0

9

2

13.6 11.8 0

3

2

5

AN St

55 33

0 0

k

p

I s t e r Group CH C H n-C H 3

2

5

4

9

and k

t

4.9 1.6 0.8

_

0 1.3

0 1.2

Table 7 of Methacrylates

a t 30°C (29)

-r— *—.—_ dm-J m o l 7

143 126 369

-l s

L

— k t dnw m o l

- 1

— s 1

12.2 x 1 0 7.35 x 1 0 10.2 x 1 0

6

6

6



8. IMOTO E T A L .

Vinyl

Polymerization

113

H e r e , t h e c o n c e p t o f t h e h a r d a n d s o f t HA a n d monomers may be r e a s o n a b l y a p p l i e d . As F i g . 10 shows, n - b u t y l e s t e r s a r e much harder than methyl o r e t h y l e s t e r . A c c o r d i n g l y , n - b u t y l methac r y l a t e a n d a c r y l a t e w e r e t o o h a r d t o be i n c o r p o r a t e d i n t o t h e s o f t HA f o r m e d b y PVPA o r s t a r c h . S t i s t o o h a r d t o b e e a s i l y i n c o r p o r a t e d i n t o t h e s o f t HA f o r m e d b y PVPA o r s t a r c h . T h e r e f o r e , t h e c o n v e r s i o n o f S t was very low. However, A s a h a r a e t a l . (32) p o l y m e r i z e d S t e a s i l y w i t h t h e i n i t i a t i n g s y s t e m o f ABS and w a t e r . The m i c e l l e s o r HA f o r m e d b y ABS i s v e r y h a r d . Therefore, S t could be e a s i l y i n c o r p o r a t e d i n t h e m i c e l l e s and e a s i l y p o l y m e r i z e d . PSS-Na c o u l d p o l y m e r i z e S t , as shown i n T a b l e 4. This exc e p t i o n a l r e s u l t s may b e e x p l a i n e d a s f o l l o w s : PSS-Na c o n t a i n s t h e p o s i t i v e l y charged phenyl group w h i c h c a n adsorb t h e n e g a t i v e l y charged phenyl group o f S t . Accordingly, regardless of the softn e s s o f t h e HA, S t c a n b e i n c o r p o r a t e d i n t o t h e HA f o r m e d b y P S S Na, t h e r e b y t a k e s p l a c e p o l y m e r i z a t i o n . AN i s t o o s o f t t o b e i n c o r p o r a t e d i n t o t h e HA f o r m e d b y s t a r c h , PVPA o r PSS-Na. (2) C o p o l v m e r i z a t i o n o f MMA w i t h S t i n HA h a v i n g V a r i o u s Hardnesses. The c o m p o s i t i o n c u r v e o f t h e c o p o l y m e r s o f MMA w i t h S t by t h e c o p o l y m e r i z a t i o n i n i t i a t e d w i t h PSS-Na was shown i n F i g . 1 1 . The c o p o l y m e r was i s o l a t e d f r o m t h e w a t e r p h a s e . The c o n t e n t s o f MMA i n t h e c o p o l y m e r a r e l a r g e r t h a n t h o s e o f S t . T h i s was due t o t h e e a s i e r i n c o r p o r a t i o n o f s o f t MMA i n t o t h e s o f t HA f o r m e d b y PSS-Na.

Figure 11. Copolymer composition curves of MMA and styrene (PSS-Na(P 85) 0.1 g, H O 5 cm , (MMA + styrene) S cm ; 85°C, 4 hr on standing) n

z

3

3



114


Second example was o b t a i n e d f r o m t h e c o p o l y m e r i z a t i o n i n i t i ated with s t a r c h . The r e s u l t s w e r e shown i n F i g . 1 2 . The c o p o l y m e r i s o l a t e d f r o m t h e monomer p h a s e was p r o d u c e d b y t h e t h e r mal p o l y m e r i z a t i o n and t h e c o m p o s i t i o n c u r v e was c o m p l e t e l y s i m i l a r t o the o r d i n a r y curve o f the r a d i c a l c o p o l y m e r i z a t i o n product. The c o p o l y m e r i s o l a t e d f r o m t h e w a t e r p h a s e d i f f e r e d f r o m t h e u s u a l copolymer. The u p p e r c u r v e i n d i c a t e d t h a t t h e HA f o r m e d b y s t a r c h w e r e s o f t , and s o f t MMA was much more e a s i l y i n c o r p o r a t e d than hard S t .

0

0.5

1.0

Mole f r a c t i o n of MMA i n monomer Figure 12. Composition curves of the copolymers of MMA and styrene by the copolymerization initiated with starch on standing (starch 0.1 g, CuCh • 2H 0 0.5 mg, H 010 cm , (MMA + styrene) 3 cm ; 85°C, 3 hr) 2

3

2

3

(3) The R a t e s o f P o l y m e r i z a t i o n o f MMA a n d S t . As known w e l l , t h e r a t e o f r a d i c a l p o l y m e r i z a t i o n (Rp) o f MMA i s l a w a y s l a r g e r t h a n t h a t o f S t (30, 3 1 ) . However, a c c o r d i n g t o A s a h a r a e t a l . ( 3 2 ) , R o f S t was l a r g e r b y 3 t i m e s o r more t h a n MMA, when t h e p o l y m e r i z a t i o n s w e r e c a r r i e d o u t i n t h e m i c e l l e s f o r m e d by ABS. The h a r d S t was i n c o r p o r a t e d e a s i e r i n t h e h a r d HA b y ABS, t h a n t h e s o f t MMA. Furthermore, the n e g a t i v e l y charged p h e n y l g r o u p o f S t c o u l d be e a s i l y a d s o r b e d on t h e p o s i t i v e l y c h a r g e d p h e n y l g r o u p o f ABS m o l e c u l e . I n v e r s e l y , PSS-Na gave t h e much l a r g e r Rp o f MMA t h a n t h a t o f St. F o r e x a m p l e , when a m i x t u r e o f 0.1 g o f P S S - N a ( P 85) d i s s o l v e d i n 5 c m o f H2O a n d 3 c m o f monomer was s h a k e n a t 85°C f o r 3 h , t h e c o n v e r s i o n o f MMA was 41.0 %, w h i l e t h a t o f S t was o n l y 20.2 %. (4) I n h i b i t i o n o f t h e P o l y m e r i z a t i o n w i t h P o t t a s i u m F l u o r i d e . As c a n be s e e n i n F i g . 1 3 , p o t t a s i u m f l u o r i d e c o u l d i n h i b i t t h e p o l y m e r i z a t i o n o f MMA i n i t i a t e d w i t h PSS-Na. T h i s i s due t o p

n

3

3


8.

IMOTO E T A L .

Vinyl

115

Polymerization


t h e a d s o r p t i o n o f f l u o r i d e a n i o n on t h e p o s i t i v e l y c h a r g e d p a r t o f MMA. The l o o s e complex o f MMA w i t h F~ was t o o s o f t t o b e i n c o r p o r a t e d i n t h e HA formed b y PSS-Na. F u r t h e r m o r e , t h e complex c o u l d n o t be a d s o r b e d on t h e s u l f o n a t e g r o u p , even i f t h e i n c o r p o r a t i o n i n t o t h e HA was p o s s i b l e i n a s m a l l e x t e n t . Accordingly, the i n i t i a t i o n r e a c t i o n d i d n o t take p l a c e .

6.

A Proposed Mechanism o f I n i t i a t i o n . The i n i t i a t i o n mechanism i n t h e s y s t e m o f PSS-Na a n d MMA was c o n s i d e r e d t o p r o c e e d a s shown i n Scheme 1 ( 2 0 ) .

Scheme 1. Proposed mechanism of the initiation reaction of the of MMA with PSS-Na

polymerization


MODIFICATION

116

O F POLYMERS

PSS-Na c o u l d i n i t i a t e t h e p o l y m e r i z a t i o n o f S t . n i s m i s assumed a s Scheme 2 ( 2 0 ) .

0 Na 1 2 JL

Charge transfer


p

SO,

Proton transfer

o

o

>

CH CH

+

0 Na 1 S0

+

S0

Na 0

0 Na 1 S0

The mecha-

0

CH

SO,

CH

0~ Na

2

SO,

+i

2

Na 0"

- C ^ © -CH

ii CH

2

SO,

•CH

so, .c

S0

2

2

iCH^i 0 Na

Na 0

Q

CH

+

CH

0

0" Na

+

3

Scheme 2. Proposed mechanism for the initiation of the polymerization of styrene by PSS-Na The i n i t i a t i o n mechanism w i t h PVPA was p r o p o s e d a s f o l l o w s (23):

-CH5—CH

.

~CH —CH 2

Q 0

{

V

? O-R

C H

3

Transfer

•

0^ —0-R

7\

?

c

I

V

*

•C-CH

of H-

1 1

0

HCH

2

CH CH

2

2

Mi

ESS -^CH^-CH—^ Q

P

°/ V

-CH —CH—^

7\ * X

0^^-0-R

of HV

"

"

' CH

C

H

!

3>

0

p. CH 2

5

Scheme 3.

•C-H HCH„

11 CH,

ESS R : CH

0^0-R

Q0

Transfer

V

.

2

Q H, C H ^ C I , CH CH OH :

2

2

Proposed mechanism for the initiation with PVPA


M,

3

8. IMOTO ET AL.

Vinyl Polymerization

Conclusion


A study on the process of the uncatalyzed polymerization was made. The conclusion was as follows; (1) The hydrophilic macromolecules form hydrophobic areas (HA) in the water phase; (2) Into the HA, vinyl monomers are incorporated; (3) Then, the radical polymerization starts in the HA. A new concept was proposed; HA are put in order from hard to soft HA, according to their hydrophobicities, and hard or soft vinyl monomer can be the most easily incorporated into the HA having corresponding hardness or softness. Experimental verifications for this concept were obtained. Literature Cited 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

Kimura, S., Takitani, T. and Imoto, M., Bull. Chem. Soc. Jpn. (1962), 35, 2012 Imoto, M., Kondo, M. and Takemoto, K., Makromol Chem. (1965), 89, 165 Simionescu, C. I., Feldman, D. and Ciubotariu, M., J. Polym. Sci. Part C (1972), 37, 173 Imoto, M., Kushibe, S. and Ouchi, T., J. Macromol. Sci.-Chem. (1977), A11, 321 Imoto, M., Takemoto, K. and Otsuki, T., Makromol. Chem. (1967), 104, 244 Imoto, M., Takemoto, K., Okuro, A. and Izubayashi, M., Makromol. Chem. (1968), 113, 111 Tanaka, Z., Kogyo Kagaku Zasshi (1971), 74, 1683 Okamoto, K., Yamamoto, T . , Kogyo Kagaku Zasshi (1971), 74, 527 Kondo, M., Yamada, K., Takemoto, K. and Imoto, M., Bull. Chem. Soc. Jpn. (1966), 39, 536 Fujie, A. and Kawai, T . , Makromol. Chem. (1975), 176, 629 Hayashi, S. and Imoto, M., Angew. Makromol. Chem. (1969), 6, 46 Ouchi, T., Nishimura, T. and Imoto, M., Kobunshi Ronbunshu (1975) , 32, 196 Imoto, M., Nishimura, T., Sakade, N. and Ouchi, T., Chem. Lett. (1975), 1119 Ouchi, T., Yoshikawa, T. and Imoto, M., J. Macromol. Sci.-Chem. (1978), A12, 1523 Sugiyama, K. and Lee, S. W., J. Polym. Sci. Polym. Lett. Ed. (1977), 15, 17: Imoto, M., Nishida, Y., Yoshikawa, T., Ouchi, T., Bull. Chem. Soc. Jpn. (1978), 51, 1456 Tang, H.-S., Kinoshita, M. and Imoto, M., J. Macromol. Sci.-Chem., (1973), A7, 831 Imoto, M., Suzuki, H. and Ouchi, T., J. Macromol. Sci.-Chem. (1976), A10, 1585 moto, M., Ouchi, T., Nakamura, Y. and Ogushi, H., J. Polym. Sci., Polym. Lett. Ed. (1975), 13, 131



118

MODIFICATION OF POLYMERS

19. Imoto, M., Yamada, T., Tatsumi, E. and Ouchi, T., Nippon Kasaku Kaishi (1977), 1883 20. Nakamura, Y., Ouchi, T. and Imoto, M., Kobunshi Ronbunshu (1976), 33, 36: Ouchi, T., Suzuki, H., Yamada, T. and Imoto, M., J. Macromol. Sci.-Chem. (1978), A12, 1561 21. Ouchi, T., Tatsumi, A. and Imoto, M., J. Polym. Sci., Polym. Chem. Ed., (1978), 16, 707 22. Ouchi, T., Yamada, T. and Imoto, Μ., Chem. Lett. (1977), 1371 23. Imoto, M., Sakae, M. and Ouchi, T., Makromol. Chem., in press 24. Imoto, M., et a l . , unpublished 25. Imoto, Μ., Takemoto, Κ., Azuma, Α., Kita, N. and Kondo, M. Makromol. Chem. (1967), 107, 188: Imoto, Μ., Kondo, Μ., Takemoto, Κ., ibid. (1965), 89, 165 26. Imoto, M., Morita, E. and Ouchi, T., J. Polym. Sci., Symposia, in press 27. Windholz, M., Ed., "Merck Index, 9th Ed." Merck and Co. New Jercy 1976 28. Chem. Soc. Jpn. Ed., "Kagaku Benran, Oyo-Hen", Maruzen, Tokyo 1973 29. Bradrup, J., Immergut, E. H., Ed. "Polymer Handbook, 2nd Ed." John Wiley and Sons, New York 1975, p. II48 30. Yokota, K., Kani, M. and Ishii, Y., J. Polym. Sci. (1968), A1, 6, 1325 32. Asahara, T., Seno, Μ., Shiraishi, S. and Arita, Y., Bull. Chem. Soc. Jpn. (1970) 43, 3895: Arita, Y., Shiraishi, S., Seno, M. and Asahara, T., Bull. Chem. Soc. Jpn. (1973), 46, 249, 2599 RECEIVED

July

12, 1979.


Radical Polymerization of Vinyl Monomer with an Aqueous Solution of

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