Synthesis and Cationic Polymerization of 1,4

16 Synthesis and Cationic Polymerization of 1,4-Dimethylenecyclohexane 1

2

L. E. BALL , A.SEBENIK ,and H. J. HARWOOD

Downloaded by UNIV OF LIVERPOOL on December 6, 2015 | http://pubs.acs.org Publication Date: August 12, 1982 | doi: 10.1021/bk-1982-0195.ch016

University of Akron, Institute of Polymer Science, Akron, OH 44325

The synthesis and polymerization characteristics of 1,4-dimethylenecyclohexane are described. Cationic polymerization of this monomer yields relatively low molecular weight polymers containing appreciable amounts of endocyclic double bonds. In contrast to our earlier claim, 1,4-dimethylenecyclohexane does not seem to cyclopolymerize to a significant extent. The p o l y m e r i z a t i o n o f nonconjugated dienes have been i n v e s t i g a t e d e x t e n s i v e l y during the l a s t 20 years and the scope of monomers that undergo c y c l o p o l y m e r i z a t i o n has been shown t o be very broad (l-_4) · T r i e n e s , c y c l i c dienes, and comonomer combinat i o n s that can y i e l d c y c l i c r a d i c a l s c o n t a i n i n g pendant unsaturat i o n , e t c . , form an i n t e r e s t i n g subclass of those monomers that undergo c y c l o p o l y m e r i z a t i o n , because they o f f e r the p o s s i b i l i t y o f i n c o r p o r a t i n g b i c y c l i c r i n g s i n t o polymeric backbones (5-_9). T h i s paper concerns the p o l y m e r i z a t i o n behavior of 1 , 4 - d i methylenecyclohexane, I , a monomer that was claimed i n an e a r l i e r r e p o r t (9) to polymerize c a t i o n i c a l l y to a f f o r d a s o l u b l e , essent i a l l y saturated polymer that was presumed to have the b i c y c l i c repeating s t r u c t u r e I I .

CH =^ 2

y=CH

2

i

hCH 2

II Subsequent ultraviolet

1 2

c h a r a c t e r i z a t i o n (10,11) of the polymer by i n f r a r e d , and nmr ( H-) - spectroscopy i n d i c a t e d the presence of X

Current address: Sohio Research Center, Cleveland, OH 44128. Current address: Kemijski Institute "Boris Kidric," Ljubljana, Yugoslavia.

0097-6156/82/0195-0207$06.00/0 © 1982 American Chemical Society

In Cyclopolymerization and Polymers with Chain-Ring Structures; Butler, G., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1982.

208

POLYMERS WITH CHAIN-RING STRUCTURES

s u b s t a n t i a l amounts of methyl groups as w e l l as a chromophore absorbing weakly at 260 nm. T h i s information c a s t doubt on the v a l i d i t y of s t r u c t u r e I I . Recent cmr s t u d i e s (12) have c l a r i f i e d the s t r u c t u r e of polymer. T h i s paper covers the s y n t h e s i s of 1,4dimethylenecyclohexane, i t s p o l y m e r i z a t i o n c h a r a c t e r i s t i c s and the r e s u l t s of recent H- and C - NMR s t u d i e s on the s t r u c t u r e s of i t s polymers. X

1 3


Synthesis and C h a r a c t e r i z a t i o n of 1,4-Dimethylenecyclohexane 1,4-Dimethylenecyclohexane was synthesized i n 54 percent y i e l d by the f o l l o w i n g r e a c t i o n . The m a t e r i a l was shown by gasl i q u i d chromatography to be b e t t e r than 99 percent pure.

I t was c h a r a c t e r i z e d by chemical a n a l y s i s , o z o n o l y s i s to form f o r maldehyde, hydrogénation, bromination and by i t s i n f r a r e d and HNMR s p e c t r a . The diene has a l s o been prepared by p y r o l y s i s of l,4-bis-(acetoxymethyl)cyclohexane (13,14), from cyclohexanedione by the W i t t i g r e a c t i o n (11,15) or by r e a c t i o n with diazomethane (16), and by the e l e c t r o c h e m i c a l or metal r e d u c t i o n of 1,4-dihalobicyclo-[2,2,2-]octanes (17,18) or of l , l , 2 , 2 - t e t r a k i s - ( b r o m o methyl)-cyclobutane (19). I t i s very s t a b l e i f s t o r e d i n ammonia r i n s e d , dry f l a s k s . X

Polymerization

Studies

Attempts to polymerize I by f r e e r a d i c a l or anion i n i t i a t e d p o l y m e r i z a t i o n techniques were u n s u c c e s s f u l . Attempts to prepare copolymers of I with S0 (10) l e d only to complex mixtures of low molecular weight products, i n c o n t r a s t to the claims of a patent (20). I t proved p o s s i b l e to polymerize I with T i C W i i B u ) A1 c a t a l y s t s at 25° when T i / A l r a t i o s of ^2.7 were employed (21) but s u b s t a n t i a l p o r t i o n s (25-75%) of the product were c r o s s l i n k e d and the s o l u b l e p o r t i o n s contained approximately one double bond f o r every two monomer u n i t s . I t seems that the double bonds i n I r e act independently during such p o l y m e r i z a t i o n s . As expected, attempts to polymerize I c a t i o n i c a l l y were more s u c c e s s f u l . Polymerizations were conducted i n methylene c h l o r i d e or i n t - b u t y l c h l o r i d e s o l u t i o n s using A I C I 3 or gaseous BF3 as c a t a l y s t s . The optimum temperature f o r p o l y m e r i z a t i o n i n methylene c h l o r i d e using BF as c a t a l y s t was between -30° and -20°C. In t h i s temperature range, i t was p o s s i b l e to prepare s o l u b l e p o l y mers having molecular weights as high as 10,000 i n up to 75 percent y i e l d . At lower temperatures, the y i e l d of polymer and i t s molecular weight were reduced c o n s i d e r a b l y . The e f f e c t of monomer c o n c e n t r a t i o n on the y i e l d of polymer obtained at -78° i s shown 2

3

3


16.

BALL

E T AL.

209

1,4-Dimethylenecyclohexone

In F i g u r e 1. I t i s seen that the y i e l d i n c r e a s e s with monomer c o n c e n t r a t i o n up to about 2 M. I t then f a l l s a t higher concentrat i o n s , presumably because of the i n f l u e n c e of monomer on the d i e l e c t r i c constant o f the r e a c t i o n mixture. Table I summarizes the r e s u l t s obtained i n s t u d i e s on the c a t i o n i c p o l y m e r i z a t i o n o f 1,4-dimethylenecyclohexane.


Polymer C h a r a c t e r i z a t i o n A polymer prepared a t -30° softened a t approximately 175°. I t s c r y o s c o p i c a l l y determined molecular weight was 8400. Unsatu r a t i o n determinations by bromination and hydrogénation i n d i c a t e d the presence of approximately one double bond per molecule. These determinations were m i s l e a d i n g , however, because subsequent nmr s t u d i e s , e s p e c i a l l y C-NMR s t u d i e s , i n d i c a t e d the presence o f an a p p r e c i a b l e amount o f u n s a t u r a t i o n . The i n f r a r e d and e a r l y HNMR s p e c t r a (60 MHz) of the polymer i n d i c a t e d the presence o f met h y l groups and a small amount o f r e s i d u a l u n s a t u r a t i o n . The i n t e n s i t y o f u l t r a v i o l e t a b s o r p t i o n by the polymer a t 258 nm (ε=27,000 per mole of polymer or c=340/monomer u n i t ) suggested that one diene r e s i d u e may have been present per polymer c h a i n . 13

1

I n f r a r e d S t u d i e s . F i g u r e 2 shows the r e l a t i v e absorbances at 890 CC=CH ), 1370 (-CH ), 1460 (CH ), 1660 (C=C) and 2900 (C-H)cnT observed f o r polymers prepared from -20° t o -78°. I t can be seen that the methyl content o f the polymers i n c r e a s e s and that the amount of r e s i d u a l e x o c y c l i c u n s a t u r a t i o n c o n c u r r e n t l y decreases as p o l y m e r i z a t i o n temperature i n c r e a s e s . 2

3

2

1

NMR S t u d i e s . Several poly-l,4-DMC samples prepared by B F i n i t i a t e d p o l y m e r i z a t i o n s using C H C 1 as a s o l v e n t were analyzed by H-NMR (300 MHz) and C-NMR (20 MHz) spectroscopy. These are i d e n t i f i e d as samples 13,16 and 22 i n Table I. In a d d i t i o n t o the methanol-insoluble products obtained by pouring the r e a c t i o n mix t u r e s i n t o methanol, o l i g o m e r i c products obtained by evaporating the mother l i q u o r s from the p r e c i p i t a t i o n were a l s o examined. In a l l cases, the methanol-soluble and methanol-insoluble f r a c t i o n s y i e l d e d very s i m i l a r s p e c t r a . Consequently only the s p e c t r a o f the methanol-insoluble products w i l l be d i s c u s s e d . F i g u r e 3 shows the H-NMR spectrum of sample 22 and F i g u r e 4 shows the C-NMR s p e c t r a of samples 13, 16 and 22. These s p e c t r a i n d i c a t e the presence o f l a r g e amounts o f methyl groups and of un saturated s t r u c t u r e s . The methyl groups are o f two types — methyl groups present on s a t u r a t e d carbons (as i n d i c a t e d by Η-signals a t 0.9 ppm and C - s i g n a l s a t 25.0 ppm) and methyl groups on unsatur ated carbons (as i n d i c a t e d by ^ - s i g n a l s a t 1.65 and 2.25 ppm and by C - s i g n a l s a t 19.8-23.4 ppm). There seem t o be four types o f unsaturated s t r u c t u r e s p r e s e n t : (a) r e s i d u a l e x o c y c l i c methylene groups, I I I , are i n d i c a t e d by H - s i g n a l s a t 4.5-4.6 ppm and C s i g n a l s a t 105-106 and 146-149.5 ppm; (b) e n d o c y c l i c u n s a t u r a t i o n , 3

2

X

2

13

1

13

1 3

1 3

x

1 3



210

POLYMERS

WITH

CHAIN-RING

STRUCTURES

Figure 1. Effect of 1,4-dimethylenecyclohexane concentration on polymer yield for polymerizations conducted at —78°C using CH Cl as solvent and BF as initiator. t

t


S

16.

BALL

211

1,4-Dimethylenecyclohexane

E T AL.

TABLE I Studies on the C a t i o n i c P o l y m e r i z a t i o n of (a)



Exper.

! ? (a) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 2 0

(a)

21 22 23

Temp.

Monomer Concen. (vt%)

-22°C -78°C -22°C -78°C -78°C -78°C -78°C -78°C -78°C -78°C -78°C -50°C -45°C -40 °C -30°C -30°C -30°C -30°C -30°C -20°C -20°C -15°C -0°C

1.5 1.5 1.5 0.2 1.3 1.5 0.3 0.4 0.7 1.3 2.1 1.3 2.3 2.1 1.3 1.2 1.3 1.3 1.2 1.3 1.1 1.2 2.1

Reaction Time (Hrs.) Catalyst 5 40 3 4 4 2 2 2 2 2 2 2 6 2 1.5 3 1.5 4 3 7.5 2 6 2

AICI3 AICI3

BF3«Et 0 BF *Et 0 TiCli* SbCl BF BF BF BF BF BF BF BF BF BF BF BF BF BF BF BF BF 2

3

2

5

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

% Yield 14 12 0 0 0 0 20 27.6 32.5 36.7 8.6 9 47 17 46 37 64 58 55 2.5 74 45 0

[η]

Mol. Wt.

-

-

-

-

0.045 0.094

-

-

10,40*

-

0.076 0.058 0.079

-

C)

5,50a 8,4ocr

0.092

10,00(f

-

-

C H 2 C I 2 was used as the solvent except f o r experiments 1 and 3 ( t - B u C l ) , 4 (n-pentane), and 20 (n-hexane). C a l c u l a t e d from [nl by the f o l l o w i n g e m p i r i c a l r e l a t i o n s h i p : [η]=9.9Χ10- Μ · * 3

0

b)

71

Determined c r y o s c o p i c a l l y i n benzene.


;

c)


212


-20°

-40°

-Θ0°

P O L Y M E R I Z A T I O N

-80°

T E M P E R A T U R E f C

)

Figure 2. Relative intensities of IR absorptions of polyfl ,4-dimethylenecyclohexane) as a function of polymerization temperature. Key: A, C-H stretching at 2900 cm' ; O , C=C stretching at 1660 cm ; Q -CHg- bending at 1460 cm' ; 0,-CH bending at 1370 cm' ; and V , C=CH, absorption at 890 cm' . Relative intensities are based on the maximum intensities observed for individual peaks in the spectra of 5% (w/v) solutions of the polymers in CCl . 1

1

1

s

1

1

h


16.

BALL


E T AL.

CH

Φ

2

III


213

IV

V

VI

1

1 3

1

1 3

IV, i s i n d i c a t e d by H - s i g n a l s a t 5.3 ppm and by C - s i g n a l s a t 120.0 and 134.0 ppm; (c) conjugated e n d o c y c l i c diene s t r u c t u r e s , V, a r e i n d i c a t e d by H - s i g n a l s a t 5.5 ppm and by C - s i g n a l s a t 119.0 and 132.5 ppm; and (d) aromatic r i n g s are i n d i c a t e d by Hs i g n a l s a t 6.9-7.2 ppm and by C - s i g n a l s a t 128-136 ppm. Table I I a l l o c a t e s these resonances t o s p e c i f i c types of s t r u c t u r e s b e l i e v e d to be present i n the polymers. The assignments are based, i n p a r t , on s p e c t r a reported f o r 1-methyl-l,2-cyclohexane (22), trimethylbenzene (23) and f o r v a r i o u s compounds c o n t a i n i n g e x o c y c l i c double bonds (24, 25, 26). 1

1 3

13

By making reference t o the C-NMR s p e c t r a reported f o r a l a r g e number of b i c y c l i c hydrocarbons (27), i t was p o s s i b l e to p r e d i c t the chemical s h i f t s expected f o r any b i c y c l i c s t r u c t u r e s present i n the polymers. These are a l s o l i s t e d i n Table I I . According to these p r e d i c t i o n s , bridged methylene groups present i n ( 2 , 2 , l ) - b i c y c l i c systems should be r e s p o n s i b l e f o r absorptions at 45-52 ppm i n C-NMR s p e c t r a and a t 1.2-1.6 ppm i n H s p e c t r a . As can be seen i n F i g u r e s 3 and 4, there i s only minor a b s o r p t i o n i n t h i s r e g i o n . I t should be noted that quaternary carbons can a l s o be r e s p o n s i b l e f o r absorption i n t h i s r e g i o n . Table I I contains estimates of the r e l a t i v e amounts of v a r ious s t r u c t u r e s b e l i e v e d t o be present i n the polymers. I t i s c l e a r that the polymers have very complicated s t r u c t u r e s . 13

1

Discussion Although s o l u b l e polymers can be prepared by c a t i o n i c p o l y m e r i z a t i o n of 1,4-dimethylenecyclohexane, a number of f a c t o r s make i t u n l i k e l y that t h i s monomer undergoes a p p r e c i a b l e cyclopolymer i z a t i o n . I n f r a r e d and nmr spectroscopy show that the polymers p r e pared a t -78° c o n t a i n a p p r e c i a b l e q u a n t i t i e s o f e x o c y c l i c double bonds, and that polymers prepared a t higher temperatures c o n t a i n a p p r e c i a b l e amounts of methyl groups. Carbon and proton magnetic resonance spectroscopy show that the methyl groups are present on both saturated and unsaturated carbon atoms. I n a d d i t i o n , the C-NMR s p e c t r a o f the polymers c o n t a i n strong s i g n a l s f o r unsatur ated carbon atoms. Polymers prepared a t -78° c o n t a i n mostly exo c y c l i c double bonds and tend to be c r o s s l i n k e d . Polymers prepared at higher temperatures c o n t a i n mostly e n d o c y c l i c double bonds and some aromatic r i n g s . These r e s u l t s and the f a c t that the polymer13


214

POLYMERS WITH CHAIN-RING

STRUCTURES

TABLE I I NMR A n a l y s i s o f S t r u c t u r e s In Poly(1,4-Dimethylenecyclohexane) Average No. Chemical S h i f t s (ppm) Per Repeat U n i t

Structure

i

U Ç

H

-15°

-45°

0.5

0.45

0.03

0.08

0.45

0.40

0.05

0.08

40-48


- C H

^

2

=cf

^

1.2-1.6

48-52

-

132.5-134.0

5.3

120.0

1.65

23.4

\ v/

^CHj

=C^ „

4.5-4.6 >=CH

105.0-106.0

2

146.0-149.0

0.8-1.0 >^CH

25.0

3

7.0

128.5-131.0

2.25

19.8-20.8

CH.

CH

3

-

5.5

133.0-136.0

119.0 0.03 132.5


BALL

ET AL.

215



16.

• 160

l

I 140

ι

I 120

ι

ι 100

ι

ι 80

ι

ι Θ0

ι

1 40

1

1 20

1

L 0

Ho(ppm) Figure 4.

1S

20 MHz C-NMR spectra of poly( 1,4-dimethylenecyclohexane), Sampies 13,16, and 22, in CCl solution at room temperature. k



216


i z a t i o n s proceed best between -30° and -15° suggest that proton transfer-rearrangement processes may be a s i g n i f i c a n t f e a t u r e of c a t i o n i c 1,4-dimethylenecyclohexane p o l y m e r i z a t i o n s . Since double bonds e x o c y c l i c to six-membered r i n g s r e a d i l y rearrange t o endocyc l i c double bonds, i t i s reasonable to expect the f o l l o w i n g t r a n s formations to occur a t the higher p o l y m e r i z a t i o n temperatures:

I

VII

VIII

Monomers I and V I I might be r e s p o n s i b l e f o r the i n c o r p o r a t i o n of a l a r g e number of d i f f e r e n t s t r u c t u r a l u n i t s i n the polymers, v i z .



16.

BALL

E T AL.


217

The above r e a c t i o n s can e x p l a i n the i n c o r p o r a t i o n of u n i t s with e n d o c y c l i c u n s a t u r a t i o n i n t o the polymers. The h i g h l y hindered e n d o c y c l i c double bonds present i n such s t r u c t u r e s probably have low p o l y m e r i z a t i o n c e i l i n g temperatures and would r e s i s t polymeriz a t i o n . They could be d i f f i c u l t t o brominate o r hydrogenate. I t i s our f a i l u r e t o a p p r e c i a t e the l i m i t e d r e a c t i v i t y o f e n d o c y c l i c double bonds i n s t r u c t u r e s such as IV, IX and X that caused us to overlook them i n our o r i g i n a l i n v e s t i g a t i o n (9) · T h i s l i m i t e d r e a c t i v i t y a l s o e x p l a i n s why s o l u b l e polymers can be formed i n 1,4dimethylenecyclohexane polymerizations even when c y c l o p o l y m e r i z a t i o n does not seem to occur. The r e a c t i o n s depicted above a l s o e x p l a i n the presence of a small amount o f conjugated diene u n i t s present i n the polymers. The methyl groups present on saturated carbon atoms i n the polymers can be explained i n a number of ways. P o l y m e r i z a t i o n o f e n d o c y c l i c double bonds i s one such p o s s i b i l i t y . Although i t i s probably not reasonable to expect such behavior from s t r u c t u r e s such as I I I , IV, IX or X, f o r reasons already d i s c u s s e d , the f o l lowing r e a c t i o n seems f e a s i b l e :

O x i d a t i o n - r e d u c t i o n processes i n v o l v i n g V I I I or r e l a t e d s t r u c t u r e s and unsaturated s t r u c t u r e s present i n the system ( i n c l u d i n g endoc y c l i c double bonds) are probably an a d d i t i o n a l source of methyl groups on saturated carbon atoms i n the polymers. Such r e a c t i o n s w i l l be d r i v e n by the great tendency of V I I I and r e l a t e d s t r u c t u r e s to aromatize, v i z .

VIII

XI

A l k y l a t i o n of aromatic s t r u c t u r e s formed by t h i s process could be r e s p o n s i b l e f o r the small amount of aromatic r i n g s incorporated i n the polymers.


POLYMERS


218

WITH CHAIN-RING STRUCTURES

I t thus appears that the p r i n c i p a l s t r u c t u r a l f e a t u r e s found i n poly(1,4-dimethylenecyclohexane) can be explained by conven t i o n a l carbonium i o n chemistry. There i s no i n d i c a t i o n that c y c l o p o l y m e r i z a t i o n occurs i n these p o l y m e r i z a t i o n s and there i s much evidence to i n d i c a t e that the double bonds present i n t h i s diene r e a c t independently. Some of them are i n v o l v e d i n p o l y m e r i z a t i o n r e a c t i o n s , but a l a r g e p r o p o r t i o n isomerize to r e l a t i v e l y s t a b l e e n d o c y c l i c double bonds. Under p o l y m e r i z a t i o n c o n d i t i o n s where i s o m e r i z a t i o n i s f a v o r a b l e , s o l u b l e , unsaturated polymers having complex s t r u c t u r e s are obtained. When i s o m e r i z a t i o n r e a c t i o n s are not f a v o r a b l e (low temperatures, use of Z i e g l e r - N a t t a c a t a l y s t s ) , the double bonds polymerize independently and c r o s s l i n k e d products are obtained. Experimental 1,4-dimethylenecyclohexane - A mixture of potassium metal (59.6g., 1.57 mole) and t-butanol (1-1.) was s t i r r e d under r e f l u x i n a n i t r o g e n atmosphere f o r 2 h r s . To the r e s u l t i n g s o l u t i o n of potassium t-butoxide i n t-butanol was added trans-1,4-di(iodomethyl)-cyclohexane (28) (182g., 0.5 mole). The mixture was r e f l u x ed and s t i r r e d under n i t r o g e n f o r 24 h r s . The mixture was t r e a t e d with 2400 ml water and the organic l a y e r which separated was wash ed 4 times with 200 ml p o r t i o n s of water, f i l t e r e d and d r i e d over anhydrous MgSOi*. The l i q u i d was then d i s t i l l e d under reduced pressure to o b t a i n 28.8g. (53% y i e l d ) 1,4-dimethylenecyclohexane, b.p. 54-55° (75 mm), n * 1.4688, d * 0.8133. Anal. - Calc'd f o r C H (108.2): C, 88.82; H, 11.18, Bromi n a t i o n Eq. Wt. 54.1. Found: C, 88.86, H, 11.27, Bromination Eq. Wt. 53.6. The diene q u i c k l y absorbed 1.96 moles of hydrogen when hy dro genated at room temperature u s i n g platinum as a c a t a l y s t . O z o n o l y s i s of the diene i n dry pentane a t -20°, f o l l o w e d by t r e a t ment of the r e a c t i o n mixture with a d i l u t e s o l u t i o n of dimedon provided a 56 percent y i e l d of the dimedon d e r i v a t i v e of formalde hyde, m.p. 188.5-190° The H-NMR spectrum of the diene c o n s i s t e d of two sharp s i n g l e t s a t 2.09 (-CH -) and 4.66 (=CH ) ppm having r e l a t i v e i n t e n s i t i e s of 2:1. The diene absorbed only weakly i n the u l t r a v i o l e t r e g i o n at 262 nm (ε=11.0) and at 234 nm (ε=14.7). In the presence of i o d i n e , i t absorbed at 298 nm (ε'=47.7). T h i s i s i n goodagreement with r e s u l t s expected f o r 1,4-dimethylenecyclohexane based on data reported by Long and Neuzil.(29) B u t l e r and Van Heiningen have a l s o i n v e s t i g a t e d the uv a b s o r p t i o n of t h i s monomer ( 8 ) . 5

2 5

D

8

1 2

1

2

2

P o l y m e r i z a t i o n of 1,4-Dimethylenecyclohexane w i t h B F - A 100 ml two-neck f l a s k was r i n s e d with d i l u t e NH3 s o l u t i o n and d r i e d i n a i r at 150°C. While s t i l l hot, the f l a s k was f l u s h e d with n i t r o g e n and one of the necks was equipped with a rubber gum 3


16.

BALL

219


ET AL.

s e a l . A f t e r the f l a s k had cooled under N to room temperature, 1,4-dimethylenecyclohexane (6.7 g., 0.062 mole) and methylene c h l o r i d e (42 ml) were added by s y r i n g e . While maintained under n i t r o g e n , the mixture was s t i r r e d m a g n e t i c a l l y and cooled by immer s i o n i n a bromobenzene - Dry Ice bath a t -30°C f o r one-half hour. Boron t r i f l u o r i d e was then introduced very slowly i n t o the n i t r o gen stream flowing over the r e a c t i o n mixture u n t i l a red-orange c o l o r developed i n the mixture. The mixture was maintained under n i t r o g e n and s t i r r e d a t -30°C f o r 3 hours. T r i e t h y l a m i n e (1 ml) was then i n j e c t e d i n t o the mixture and the c o l o r disappeared. The mixture was f i l t e r e d through a coarse g l a s s f r i t i n t o 500 ml o f acetone. The polymer which coagulated was f i l t e r e d and d r i e d t o g i v e a f i n e l y d i v i d e d white s o l i d (3.75 g., 55%). The polymer was f u r t h e r p u r i f i e d by d i s s o l v i n g i t i n hot methylene c h l o r i d e , f i l t e r i n g the s o l u t i o n through a "medium" g l a s s f r i t and then adding the f i l t r a t e to 500 ml of acetone. The p r e c i p i t a t e d polymer was c o l l e c t e d and d r i e d i n a vacuum d e s s i c a t o r . The i n t r i n s i c v i s c o s i t y o f the polymer i n benzene a t 30°C was 0.079. The molecular weight, determined c r y o s c o p i c a l l y i n benzene, was 8,400. A n a l . C a l c d f o r ( C H i ) : C, 88.82; H, 11.18. Found: C, 88.72; 88.67; H, 11.28; 11.12; Bromination E q u i v a l e n t Wt., 5,200, 6,000; Grams of polymer absorbing one mole of hydrogen, 7,400, 8,200. The polymer was a white powdery s o l i d . I t was s o l u b l e i n most o r g a n i c s o l v e n t s i n c l u d i n g pentane, hexane, benzene, toluene, xylene, methylene c h l o r i d e , chloroform and carbon t e t r a c h l o r i d e . I t was i n s o l u b l e i n acetone, methanol and water. The m a t e r i a l softened and became f l u i d between 170-180°C, showing only s l i g h t discoloration. The polymer showed strong methylene a b s o r p t i o n a t 2900, 2840 and 1450 cm" i n the i n f r a r e d r e g i o n . In a d d i t i o n , weak absorp t i o n s a t 1640 and 888 cm" i n d i c a t e d the presence of a few t e r m i n a l o l e f i n i c l i n k a g e s . A b s o r p t i o n a t 1380 cm- i n d i c a t e d the presence of methyl groups. The u l t r a v i o l e t spectrum o f the polymer, measured i n c y c l o hexane s o l u t i o n , was e s s e n t i a l l y the same i n the presence o r ab sence of i o d i n e . The polymer showed only weak a b s o r p t i o n i n CH Cl2 s o l u t i o n , having a maximum o f 258 nm (ε=340/monomer u n i t o r 27,000/polymer molecule). A f t e r treatment w i t h a d i l u t e s o l u t i o n of c h l o r i n e i n CCli», the polymer no longer showed an a b s o r p t i o n maxima a t 258 nm; i n s t e a d , t a i l a b s o r p t i o n of an i n t e n s e band whose maximum would occur below 210 nm was observed. P o l y m e r i z a t i o n s conducted u s i n g other c a t a l y s t s , tempera t u r e s , s o l v e n t s , and monomer c o n c e n t r a t i o n s were conducted accord ing t o the procedure d i s c u s s e d above. The r e s u l t s are summarized i n Table I . NMR Measurements - ^•H- and C - NMR s p e c t r a of the polymers i n C D C I 3 s o l u t i o n a t ambient temperature were recorded a t 300 and 20 MHz, r e s p e c t i v e l y , u s i n g V a r i a n HR-300 (CW mode) and CFT-20 (FT mode) spectrometers. The C-NMR s p e c t r a were the r e s u l t of over 100 Κ accumulations u s i n g a p u l s e width o f 10y sec. T e t r a m e t h y l s i l a n e was used as an i n t e r n a l standard.


2

f

8

2

1

1

1

2

1 3

13


220


Acknowledgemen t We a r e pleased t o acknowledge that the p a r t i c i p a t i o n o f one of us i n t h i s study was made p o s s i b l e by a grant from the Yugoslavian Academy of Sciences.


Literature Cited 1. Butler, G.B. J. Polym. Sci., Polymer Symposium 1978, 64, 71. 2. Corfield, C.G. Chem. Soc. Rev. 1972, 1(4), 523. 3. McCormick, C.L.; Butler, G.B. J. Macromol. Sci., Rev. Macromol. Chem. 1972, C8, 201. 4. Corfield, C.G.; Aso , C.; Butler, G.B. "Progress in Polymer Science"; A.D. Jenkins, Ed.; Pergamon Press; Oxford, 1975, Vol. 4, pp 71-207. 5. Butler, G.B.; Miles, M.L.; Brey, W.C. J. Polym Sci. 1965, 3A, 723. 6. Butler, G.B.; Miles, M.L. J. Polymer Sci. 1965, 3A, 1609. 7. Frazer, A.H.; O'Neill, W.P. J. Am. Chem. Soc. 1963, 85, 2613. 8. Butler, G.B.; Van Heiningen, J.J. J. Macromol. Sci. 1974, A8, 1139, 1175. 9. Ball, L.E.; Harwood, H.J. Am. Chem. Soc., Div. Polym. Chem., Preprints 1961, 2(1), 59. 10. Ball, L.E. Ph.D. Dissertation, University of Akron 1961; Dissertation Abstr. 1961, 22, 1404; Chem. Abstr. 1962, 56, 5846 h. 11. Shannon, F.D. Ph.D. Dissertation, University of Akron 1964; Dissertation Abstr. 1965, 25, 3849; Chem. Abstr. 1965, 62, 13249c. 12. Sebenik, A; Harwood, H.J. Amer. Chem. Soc., Div. Polym. Chem., Preprints 1981, 22, 15. 13. Lautenschlaeger, F.; Wright, G.F. Can. J. Chem. 1963, 41, 1972. 14. Fr. Patent 1,323,328 (April 5, 1963); Chem. Abstr. 1963, 59, 9784. 15. St-Jacques, M.; Bernard, M. Can. J. Chem. 1969,47,2911. 16. Acker, D.S.; Blomstrom, D.C. U.S. Patent 3,115,506 (Dec. 24, 1963); Chem. Abstr. 1964, 60, 14647d. 17. Wiberg, K.B.; Epling, G.A.; Jason, M. J. Am. Chem. Soc. 1974, 96, 912. 18. Wiberg, K.B.; Burgmaier, G.J. J. Am. Chem. Soc. 1972, 94, 7396. 19. Buchta, E.; Kröniger, A. Chimia 1969, 23, 225. 20. Spainhour, J.D. U.S. Patent 3,331,819 (July 18, 1967); Chem. Abstr. 1967, 67, 74012k. 21. Denkowski, G.S. M.S. Dissertation, University of Akron 1965. 22. Marshall, J.L.; Miller, D.E., Org. Magn. Reson. 1974, 6, 395.



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23. Stothers, J.B. "Carbon-13 NMR Spectroscopy, Academic Press, New York, N.Y., 1972, 24. Johnson, L.F.; Jankowski, W.C., "Carbon-13 NMR Spectra", Wiley-Interscience, New York, 1972. 25. Pouchert, C.Y.; Campbell, J.R., "The Aldrich Library of NMR Spectra", Aldrich Chemical Co., Inc., Milwaukee, Wisconsin, 1974. 26. Olah, G.Α.; and White, A.M. J. Am. Chem. Soc. 1969, 91, 3954. 27. Lippmaa, E.; Pehk, T.; Paasivirta, J.; Belikova, N.; Plate, A. Org. Magn. Reson. 1970, 2, 581. 28. Haggis, G.H.; Owen, L.N. J. Chem. Soc. 1953, 404. 29. Long, R.D.; Neuzil, R.W. Anal. Chem. 1955, 27, 1110. RECEIVED February 1, 1982.


Synthesis and Cationic Polymerization of 1,4

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