The Synthesis of a New Class of Polyphthalocyanine Resins - ACS

3 The Synthesis of a New Class of Polyphthalocyanine Resins T. M . K E L L E R and J. R. GRIFFITH

Downloaded by GEORGE MASON UNIV on May 26, 2014 | http://pubs.acs.org Publication Date: August 28, 1980 | doi: 10.1021/bk-1980-0132.ch003

Polymeric Materials Branch, Chemistry Division, Naval Research Laboratory, Washington, D C 20375

The p r i n c i p a l d r i v i n g f o r c e behind composite development i s the requirement f o r l i g h t e r weight s t r u c t u r a l m a t e r i a l s . New design concepts u s i n g e a s i l y f a b r i c a t e d , f i b e r - r e i n f o r c e d composi t e s that combine s u p e r i o r s t i f f n e s s w i t h a h i g h s t r e n g t h - t o -weight ratio a r e needed to r e p l a c e metal s t r u c t u r e . Presently, epoxies and polyimides a r e being used but each has disadvantages. Conventional epoxy-based composites and adhesives a r e l i m i t e d to 120°C maximum s e r v i c e . Other problems a s s o c i a t e d w i t h these polymers i n c l u d e t h e i r b r i t t l e n e s s , water a b s o r p t i v i t y and e n g i neering reliability. In recent years c o n s i d e r a b l e advances have been achieved i n the synthesis of thermally s t a b l e polymers. Frequently thermal and o x i d a t i v e stability i n such m a t e r i a l s has been r e a l i z e d by the combination of aromatic and heteroaromatic u n i t s ; f o r example, the polybenzimidazoles ( 1 ) , polybenzoxazoles ( 2 ) , p o l y b e n z t h i a z o l e s ( 3 ) , p o l y q u i n a z o l i n e d i o n e s ( 4 ) , polyquinazolones ( 5 ) , p o l y imides ( 6 , 7 ) , e t c . However, p o l a r and rigid s t r u c t u r e s of h i g h symmetry, which is inherent to the aromatic and heteroaromatic r i n g s , a r e r e s p o n s i b l e f o r the general l a c k of p r o c e s s a b i l i t y of these polymers. In general more t r a c t a b l e polymeric precursors such as polyamide a c i d s ( i n the case of polyimides) a r e formed i n t o a d e s i r e d shape and then converted i n situ to the final thermally s t a b l e polymers. Because t h e final conversion g e n e r a l l y i n v o l v e s a chemical r e a c t i o n which r e l e a s e s a volatile product such as water, the use of these polymers is o f t e n l i m i t e d to a p p l i c a t i o n s such as c o a t i n g s , f i l m s and a d h e s i v e s . In our c o n t i n u i n g i n v e s t i g a t i o n of phthalocyanines (8-13), a new c l a s s of p h t h a l o n i t r i l e monomers i n which e i t h e r an alkoxy or a phenoxy l i n k a g e connects the t e r m i n a l p h t h a l o n i t r i l e u n i t s has been s y n t h e s i z e d . These monomers a r e prepared by the simple n u c l e o p h i l i c displacement of a n i t r o s u b s t i t u e n t , which i s a c t i vated by cyano groups, from an aromatic r i n g by e i t h e r an a l k o x i d e or a phenoxide u n i t . The r e a c t i o n has made i t p o s s i b l e to s y n t h e s i z e a l a r g e number of s t r u c t u r a l l y d i f f e r e n t p o l y p h t h a l o c y a nines c o n t a i n i n g ether linkages and a l k y l e n e and aromatic spacing This chapter not subject to U.S. copyright. Published 1980 American Chemical Society In Resins for Aerospace; May, C.; ACS Symposium Series; American Chemical Society: Washington, DC, 1980.

26

RESINS F O R A E R O S P A C E


units. The products from the r e a c t i o n have a l s o been hydrolyzed to the corresponding t e t r a a c i d s which are r e a d i l y converted to the corresponding b i s (anhydrides) (14). N u c l e o p h i l i c aromatic displacement of a c t i v a t e d n i t r o groups has been the subject of many i n v e s t i g a t i o n s (15,16,17). In general a n i t r o group can be r e a d i l y d i s p l a c e d when i t i s p o s i tioned ortho or para to another s u b s t i t u e n t capable of s t a b i l i z i n g a negative charge. Numerous examples of n i t r o displacement i n v o l v i n g a c t i v a t i o n by s u l f o n e , carboxamide, ketone, phenyl, e s t e r , aldehyde and cyano s u b s t i t u e n t s have appeared i n the l i t e r a t u r e (18-23). R e s u l t s and D i s c u s s i o n The fundamental approach to generation of new polymeric m a t e r i a l s i n v o l v e s a determination of the complex of p r o p e r t i e s d e s i r e d i n the product and s e l e c t i n g those molecular c o n s t i t u e n t s f o r these s t r u c t u r e s which can reasonably be expected to y i e l d the d e s i r e d r e s u l t s . In the case of thermally s t a b l e polymers, i t i s necessary to avoid the i n c l u s i o n of chemical s t r u c t u r e s which are known to decompose or o x i d i z e at temperatures below the p r o j e c t e d l e v e l s . W a t e r - r e s i s t a n t polymers should be composed of a maximum of hydrophobic s t r u c t u r e and a minimum of h y d r o p h i l i c groups c o n s i s t a n t w i t h other d e s i r e d p r o p e r t i e s . Our i n t e r e s t i n polymers w i t h h i g h thermal and o x i d a t i v e s t a b i l i t i e s , low f l a m m a b i l i t y w i t h h i g h char formation, chemical r e s i s t a n c e and low water a b s o r p t i v i t y prompted our study of e t h e r c o n t a i n i n g polyphthalocyanines. The l i n k i n g s t r u c t u r e between the two terminal p h t h a l o n i t r i l e u n i t s must p l a y a c r u c i a l r o l e i n

determining p r o p e r t i e s f o r they c o n t r o l the f l e x i b i l i t y of the polymer chain and determine the o v e r a l l p o l a r i t y of the macromolecule. Thus, to o b t a i n the p r o p e r t i e s r e q u i r e d , these l i n k s should be s e l e c t e d such that good s t a b i l i t y i s r e t a i n e d and the polymer backbone i s s u f f i c i e n t l y f l e x i b l e w i t h a l i p h a t i c m o i e t i e s being more f l e x i b l e than aromatic u n i t s . The r e a l problem has been to devise s y n t h e t i c methods f o r l i n k i n g aromatic n u c l e i w i t h s u f f i c i e n t v e r s a t i l i t y and freedom from s i d e r e a c t i o n s to e f f e c t the synthesis of a wide range of h i g h molecular weight polymers i n the hope that some of these would show the p r o p e r t i e s r e q u i r e d . The f l e x i b l e ether l i n k a g e was a n a t u r a l choice f o r c o n s i d e r a t i o n due to the thermal s t a b i l i t y p a r t i c u l a r l y of d i a r y l ethers and to the chemical r e s i s t a n c e of the ether bond i n g e n e r a l . H i g h l y aromatized monomers i n which a phenoxy l i n k a g e connects the t e r m i n a l p h t h a l o n i t r i l e moieties are e a s i l y synthesized i n high y i e l d . A v a r i e t y of monomers depending on the p r o p e r t i e s

In Resins for Aerospace; May, C.; ACS Symposium Series; American Chemical Society: Washington, DC, 1980.

3.

K E L L E R AND GRIFFITH

Phthalocyanine

d e s i r e d can be prepared by t h i s method. ^^/ R --0H + 2

EOÔy

I0X

C N

C

N

B

a

s

^

27

Resins

ν

e

^

The r e a c t i o n

involves yCl

NC, N

t

C

H

^

O

^

R

^

O

^

.

ON' 1


a; R = CH.CCH. b; = CF^CCF^ ç; = SO*

Heat, neat or metallic additive Polyphthalocyanine 4

the n u c l e o p h i l i c displacement of the l a b i l e n i t r o s u b s t i t u e n t from 4 - n i t r o p h t h a l o n i t r i l e 1 by a b i s p h e n o l 2_ i n the presence of a base and i n a dry d i p o l a r a p r o t i c solvent under an i n e r t atmosphere. Higher y i e l d s of .3 are obtained when the r e a c t i o n i s c a r r i e d out at room temperature. P h t h a l o n i t r i l e monomers w i t h alkoxy l i n k i n g u n i t s can be prepared by the same method, but the r e a c t i o n i s more s l u g g i s h and the y i e l d s are lower. I f a weak base such as anhydrous potassium carbonate i s used, an amount i n excess of stoichiometry i s p r e f e r r e d and i t must be added i n increments to ensure a complete reaction. I t i s t h e o r i z e d that the c e s s a t i o n i s due to the Base HO(CH ) OH + 1 2

n

NCv W NCÔ(CH ) O-@-CN C

2

N

n

Heat, neat or metallic additive Polyphthalocyanine ι

surface of the carbonate becoming coated during the course of the reaction. When a strong base such as sodium hydroxide i s used, the disodium s a l t of _5 i s prepared and the by-product (water) i s removed before jL i s added. To ensure a h i g h conversion to 6^ the r e a c t i o n must be c a r r i e d out at elevated temperatures. From our observation i t appears that the n i t r o displacement r e a c t i o n s described above occur by means of the c l a s s i c a l a d d i t i o n - e l i m i n a t i o n mechanism of n u c l e o p h i l i c aromatic s u b s t i t u t i o n (24). The high y i e l d s and absence of s i d e r e a c t i o n s , other than those l e a d i n g to n i t r o group displacement, support t h i s mechanism, although an a l t e r n a t e route i n v o l v i n g r a d i c a l anion intermediates cannot be r u l e d o u t .



28

RESINS

FOR AEROSPACE

P o l y m e r i z a t i o n o f 3^ a n d 6^ o c c u r s b y a c y c l i c a d d i t i o n r e a c t i o n without f o r m a t i o n o f v o l a t i l e by-products t o produce s o l i d , v o i d - f r e e p r o d u c t s , _4 a n d 7_, r e s p e c t i v e l y . P h t h a l o c y a n i n e f o r m a t i o n i s b e l i e v e d t o be t h e p r i n c i p a l r e a c t i o n due m a i n l y t o t h e t e r m i n a l p h t h a l o n i t r i l e u n i t s o f t h e monomers and t o t h e d e v e l o p ment o f t h e g r e e n c o l o r d u r i n g t h e p o l y m e r i c p r o g r e s s i o n , b u t o t h e r c y a n o - a d d i t i o n r e a c t i o n s may a l s o o c c u r . When h e a t e d n e a t , g e l a t i o n o c c u r s more r e a d i l y f o r t h e a l i p h a t i c monomer j> t h a n f o r t h e more a r o m a t i z e d monomer 4_. The c u r e t i m e o f b o t h t y p e s o f monomers c a n b e g r e a t l y r e d u c e d b y t h e a d d i t i o n o f m e t a l l i c additives. The e a s e o f p o l y m e r i z a t i o n o f t h e a l k o x y - l i n k e d p h t h a l o n i t r i l e s j> d e p e n d s o n t h e l e n g t h o f t h e l i n k a g e b e t w e e n t h e t e r m i n a l p h t h a l o n i t r i l e m o i e t i e s . A t a g i v e n t e m p e r a t u r e , t h e more f l e x i b l e o r longer spacing u n i t s r e q u i r e l e s s time t o cure. Regardl e s s o f the temperature, t h e heating i s continued u n t i l the melt s o l i d i f i e s t o a n e x t r e m e l y h a r d m a t e r i a l . The p o l y m e r i z a t i o n c a n be c a r r i e d o u t i n a n o x y g e n - c o n t a i n i n g , i n e r t o r vacuum a t m o s phere. A p o s t c u r e a t a t e m p e r a t u r e f r o m 210°C t o 2 4 0 C i s u s e d t o improve t h e s t r e n g t h o f t h e r e s i n . In the case o f the h i g h l y aromatized l i n k i n g u n i t s , p o l y m e r i z a t i o n i s more d i f f i c u l t a n d r e q u i r e s much h i g h e r t e m p e r a t u r e s f o r g e l a t i o n . The monomers _3 a r e c u r e d a t 260-290°C a n d r e q u i r e s e v e r a l days o f continuous h e a t i n g b e f o r e a v i s c o s i t y i n c r e a s e i s d e t e c t e d . The s l o w r a t e o f p o l y m e r i z a t i o n c o u l d b e a t t r i b u t a b l e to t h e r i g i d i t y of t h e l i n k i n g s t r u c t u r e which reduces the m o b i l ty of the reaction sites. The p h t h a l o n i t r i l e monomers c a n b e p o l y m e r i z e d s t e p w i s e t o d i s t i n c t s t a g e s . The method c o m p r i s e s h e a t i n g t h e monomers a t a s p e c i f i e d temperature u n t i l t h e v i s c o s i t y s t a r t s t o i n c r e a s e due t o t h e o n s e t o f p h t h a l o c y a n i n e f o r m a t i o n ( B - s t a g e ) . The p r e p o l y mer c a n t h e n b e c o o l e d t o a f r a n g i b l e s o l i d a n d c a n b e s t o r e d i n d e f i n i t e l y without further reaction. The p r e p o l y m e r c a n e i t h e r be r e m e l t e d and heated u n t i l s o l i d i f i c a t i o n o c c u r s (C-stage) o r c a n be p u l v e r i z e d and t h e n p r o c e s s e d i n any d e s i r e d form. The optimum c u r e f o r a n y r e s i n a t a p a r t i c u l a r t e m p e r a t u r e i s d e t e r mined e m p i r i c a l l y by t e s t i n g t h e s t r u c t u r a l s t r e n g t h over a range of cure times. The p o l y p h t h a l o c y a n i n e s 4· a n d 1_ show h i g h t h e r m a l a n d o x i d a t i v e s t a b i l i t i e s ( s e e F i g u r e 1 ) . P o l y m e r 7_ w i t h s t o o d t e m p e r a t u r e s g r e a t e r t h a n 200°C w i t h o u t d e g r a d a t i o n , a n d 230°C w i t h s l i g h t d e g r a d a t i o n , b u t decomposed when h e a t e d a b o v e 250°C f o r a n e x t e n d ed p e r i o d . P o l y m e r 4^was s t a b l e f o r a n e x t e n d e d p e r i o d a t 280°C b e f o r e a n y w e i g h t l o s s o c c u r r e d . S u r p r i s i n g l y , 4^ i n i t i a l l y showed a s m a l l w e i g h t i n c r e a s e a t 250°C, w h i c h i s p r o b a b l y d u e t o o x y g e n a b s o r p t i o n , and t h e n s l o w l y l o s t w e i g h t ( 1 % a f t e r a p p r o x i m a t e l y 4 m o n t h s ) when h e l d a t t h i s t e m p e r a t u r e f o r p r o l o n g e d p e r i o d s . The g r e a t e r t h e r m a l s t a b i l i t y o f 4_ r e l a t i v e t o ]_ m u s t b e a t t r i b u t e d t o t h e n a t u r e o f t h e l i n k a g e w i t h d i a r y l e t h e r s b e i n g more s t a b l e than a r y l - a l k y l ethers. e


3.

KELLER

AND GRIFFITH

Phthalocyanine

29

Resins

The water a b s o r p t i v i t y of a polyphthalocyanine w i l l a l s o depend on the l i n k i n g s t r u c t u r e between the phthalocyanine n u c l e i . Polar groups l o c a t e d on the l i n k i n g s t r u c t u r e would be expected t o show a stronger a t t r a c t i o n f o r water than nonpolar groups. Poly mers 4a, 4b and _7, which c o n t a i n no p o l a r u n i t s , show a s i m i l a r and low a f f i n i t y f o r water (see F i g u r e 2 ) . On the other hand, 4c has a much stronger a t t r a c t i o n f o r water which must be r e l a t e d t o the p o l a r suIfone group being present i n the molecule.


Conclusions We have shown the s y n t h e t i c u t i l i t y of n u c l e o p h i l i c d i s placements of a n i t r o group a c t i v a t e d by cyano f u n c t i o n s . In our s t u d i e s , h i g h l y aromatized low-cost bisphenol systems are being emphasized i n an e f f o r t to maximize the char d e n s i t y of the r e s i n s . Exposure and removal of samples of these polymers from a high temperature flame has demonstrated that these r e s i n s are s e l f - e x t i n g u i s h i n g . The synthesis of these r e s i n s i s short and simple and takes advantage of r e l a t i v e l y inexpensive s t a r t i n g m a t e r i a l s . In a d d i t i o n to the s t r u c t u r a l v a r i a t i o n s , the cost t o produce these r e s i n s should be competitive with that of other h i g h temperature polymeric systems. The d i e t h e r - l i n k e d polyphthalocyanines provide a new matrix r e s i n system with long-term opera t i o n a l c a p a b i l i t y i n excess of 250 C w i t h i n s e n s i t i v i t y to h i g h humidity and w i t h the a b i l i t y to r e t a i n r e i n f o r c i n g f i b e r s during or f o l l o w i n g exposure to a f i r e environment. e

Experimental Synthesis of B i s (3,4-Dicyanophenyl)

Ether of Bisphenol A 3a.

A mixture of 125 g (0.55 mol) of bisphenol A, 275 g (2.0 mol) of anhydrous potassium carbonate, 190 g (1.1 mol) of 4 - n i t r o p h t h a l o n i t r i l e and 900 ml of dry dimethyl s u l f o x i d e was s t i r r e d and heated at 55-60°C f o r 4 hours under a n i t r o g e n atmosphere. A f t e r c o o l i n g the product mixture was slowly poured i n t o 2000 ml of c o l d d i l u t e h y d r o c h l o r i c a c i d . The p r e c i p i t a t e was i s o l a t e d by s u c t i o n f i l t r a t i o n and washed with water u n t i l n e u t r a l . The crude, d r i e d product was p u l v e r i z e d and washed thoroughly w i t h hot absolute ethanol which removed the i m p u r i t i e s . The pure product (230 g, 87%), m.p. 196-199 C, being i n s o l u b l e i n ethanol was c o l l e c t e d and analyzed; i r (KBr) 3080-3020 ( = C H ) , 2238 (CN), 1580 (C=C), 15001470 (aromatic), 1310-1170 cm" (CO); nmr (CDC1 ) δ 1.73 ( s i n g l e t , 6H), 7.63 ( m u l t i p l e t , 14H); A n a l . Calcd f o r ^ o 4 2 > 77.48; H, 4.20; N, 11.66; 0, 6.66. Found: C, 77.21; H, 4.26; N, 11.54; 0, 6.93. A second mixture of 10 g (0.04 mol) of bisphenol A, 3.6 g (0.09 mol) o f 50% sodium hydroxide, 70 ml of dimethyl s u l f o x i d e and 30 ml of benzene was s t i r r e d at r e f l u x f o r 3 hours under a n i t r o g e n atmosphere and the water was azeotroped from the mixture e

1

Q

c

3

H

N

0

:

C

2



30

RESINS

1200 1600 2000 TIME (HOURS)

2400

FOR

AEROSPACE

2800

Figure 1. Weight loss at elevated temperature of diether-linked polyphthalocyanines: (X) 1,12-dodecanediol-linked polymer at 250°C; (Φ) bisphenol A-linked polymer at 280°C; (A) bisphenol S-linked polymer at 280°C; (O) bisphenol A6F-linked polymer at 280°C

1200 1600 TIME (HOURS)

2000

2400

2800

Figure 2. Water absorption of diether-linked polyphthalocyanines on immersion in water at room temperature: (χ) bisphenol S-linked polymer; (Φ) 1,12-dodecanediol-linked polymer; (±) bisphenol Α-linked polymer; (O) bisphenol A6Flinked polymer


3.

K E L L E R A N D GRIFFITH

Phthalocyanine

Resins

31


with a Dean-Stark t r a p . The benzene was removed by d i s t i l l a t i o n and 15.7 g (0.09 mol) of 4 - n i t r o p h t h a l o n i t r i l e was added to the r e a c t i o n mixture a t room temperature. The r e s u l t i n g dark mixture was s t i r r e d a t room temperature overnight. The mixture was poured i n t o 300 ml of c o l d water and the white s o l i d which separated was c o l l e c t e d by s u c t i o n f i l t r a t i o n , washed w i t h water, d r i e d and washed w i t h hot absolute ethanol to y i e l d 20.7 g (98%) o f the de s i r e d product, m.p. 196-199°C. Synthesis of B i s (3,4-Dicyanophenyl) E s t e r of Hexafluoroacetone Bisphenol A 3b, A mixture of 10.1 g (0.03 mol) of hexafluoroacetone b i s p h e n o l A, 10.4 g (0.06 mol) of 4 - n i t r o p h t h a l o n i t r i l e , 12.4 g (0.09 mol) o f anhydrous potassium carbonate and 60 ml of dry dimethyl s u l f o x i d e was s t i r r e d under a n i t r o g e n a t mosphere a t 70-80°C f o r 6 hours. The cooled product mixture was poured i n t o 300 ml o f c o l d d i l u t e h y d r o c h l o r i c a c i d . The p a l e brown product which separated was c o l l e c t e d by s u c t i o n f i l t r a t i o n and washed w i t h water u n t i l n e u t r a l . The crude m a t e r i a l was r e c r y s t a l l i z e d from a c e t o n i t r i l e to g i v e 13.8 g (78%), m.p. 230233°C, of the d e s i r e d product; i r (KBr) 3105-3020 (=CH) ; 2238 (CN), 1590 (C=C), 1520-1485 (aromatic), 1320-1140 cm (CFÔ) ; nmr (acetone-d^)ό 7.73 ( m u l t i p l e t , 14H); F nmr (CFCl^ e x t e r n a l ref.) - 63.42 ppm ( s i n g l e t , 6F) ; A n a l . Calcd f o r C ^ H ^ F ^ C ^ : C, 63.29; H, 2.38; F, 19.37; N, 9.52; 0, 5.44. Found: C, 63.38; H , 2.62; F, 19.37; N, 9.61; 0, 5.02. 1

9

A second mixture containing 67.2 g (0.21 mol) o f h e x a f l u o r o acetone b i s p h e n o l A, 16.5 g (0.4 mol) of 50% aqueous sodium hy droxide, 300 ml of dimethyl s u l f o x i d e and 75 ml of benzene was s t i r r e d a t r e f l u x f o r 15 hours under a n i t r o g e n atmosphere and the water was removed w i t h a Dean-Stark t r a p . The benzene was r e moved by d i s t i l l a t i o n and 69.4 g (0.4 mol) of 4 - n i t r o p h t h a l o n i t r i l e was added t o the r e a c t i o n mixture a t room temperature. The r e s u l t i n g dark mixture was s t i r r e d a t room temperature f o r 12 hours under a n i t r o g e n atmosphere. The cooled mixture was then poured i n t o 800 ml of cold water and the p a l e brown product was c o l l e c t e d by s u c t i o n f i l t r a t i o n . R e c r y s t a l l i z a t i o n from aceto n i t r i l e y i e l d e d 107 g (91%) of product. Synthesis of B i s (3,4-Dicyanophenyl) Ether of B i s p h e n o l S 3c. A mixture of 51 g (0.2 mol) of b i s p h e n o l S, 16.4 g (0.4 mol) of 50% aqueous sodium hydroxide, 450 ml of dimethyl s u l f o x i d e and 100 ml of benzene was s t i r r e d a t r e f l u x f o r 6 hours. The water and benzene was removed with a Dean-Stark t r a p . The r e a c t i o n content was cooled t o room temperature and 69.4 g (0.4 mol) of 4n i t r o p h t h a l o n i t r i l e was added i n one sum. The r e s u l t i n g mixture was s t i r r e d f o r 12 hours a t room temperature under a n i t r o g e n atmosphere and then poured i n t o 1500 ml of c o l d water. The s l i g h t l y colored s o l i d which separated was c o l l e c t e d by s u c t i o n f i l t r a t i o n , washed with water and d r i e d . The product was then washed w i t h 400 ml of hot ethanol to a f f o r d 99.2 g (98%) of


32

RESINS

FOR AEROSPACE

product, m.p. 231-233°C; i r (KBr) 3100-3080 (=CH), 2238 (CN), 1600-1560 (C=C), 1470 (aromatic), 1310-1100 cm ( S 0 , CO); nmr (DMS0-d ) δ 7.81 ( m u l t i p l e t , 14H) ; A n a l . Calcd f o r C ^ H ^ N ^ S : C, 66.92; H, 2.81; N, 11.15; 0, 12.74; S, 6.38. Found: C, 66.65; H, 2.85; N, 11.29; 0, 12.67; S, 6.29. 2


6

Synthesis of 1,12-Bis (3,4-Dicyanophenoxy) Dodecane A mix ture o f 1,12-dodecanediol (2.2 g , 0.01 mol), anhydrous potassium carbonate (4.1 g , 0.03 mol), 35 ml of dimethylformamide and 25 ml of benzene was heated a t r e f l u x under a n i t r o g e n atmosphere f o r 12 hours. A small q u a n t i t y of water was c o l l e c t e d i n a Dean-Stark t r a p . The benzene was then removed by d i s t i l l a t i o n and the reac t i o n mixture cooled to room temperature. 4 - N i t r o p h t h a l o n i t r i l e (4.0 g, 0.02 mol) was added i n one sum which r e s u l t e d i n an imme d i a t e c o l o r change to a deep b l u e . A f t e r 10 minutes a t room temperature, the r e a c t i o n medium had turned t o a y ellowish-orang e and remained t h i s c o l o r throughout the e n t i r e r e a c t i o n . The mix t u r e was s t i r r e d and heated a t 100°C f o r 16 hours under a n i t r o g e n atmosphere. The cooled r e a c t i o n mixture was poured i n t o 200 ml of c o l d d i l u t e h y d r o c h l o r i c a c i d and extracted w i t h three, 75 ml p o r t i o n s of chloroform. The combined e x t r a c t was washed w i t h water, d r i e d over anhydrous sodium s u l f a t e , charcoaled and con centrated a t reduced pressure. R e c r y s t a l l i z a t i o n of the crude product from ethanol-water y i e l d e d 3.1 g (70%) of 6^, m.p. 104107°C; i r (KBr) 3110-3040 (=CH), 2930-2850 (CH), 2238 (CN), 1600 (C=C), 1490-1470 (aromatic), 1350-1250 (aromatic CO), 1100-1010 cm" ( a l i p h a t i c CO); nmr (CDC1-) δ 1.52 ( m u l t i p l e t , 2OH), 4.01 ( t r i p l e t , 4H), 7.55 ( m u l t i p l e t , 6H); A n a l . Calcd f o r 8 3 0 4 ° 2 C, 74.00; H, 6.65; N, 12.33; 0, 7.04. Found: C, 73.71; H, 6.69; N, 12.39; 0, 7.21. C

H

N

:

2

P o l y m e r i z a t i o n of 3, Samples (1-2 g) o f 3_ were placed i n planchets and heated a t 280°C f o r 7 days. A v i s c o s i t y i n c r e a s e , which i n d i c a t e d that p o l y m e r i z a t i o n was p r o g r e s s i n g , occurred v e r y slowly. A f t e r g e l a t i o n (3-4 days) the samples were postcured f o r 3 a d d i t i o n a l days to ensure complete p o l y m e r i z a t i o n and to toughen the polymers. Samples o f _3 and s to ichiometr i c amounts o f stannous c h l o r i d e d i h y d r a t e were heated a t 220-250°C f o r 24 hours. A f t e r the mono mers melted, the samples q u i c k l y turned green along w i t h an imme d i a t e d i s s o l u t i o n of the s a l t . The v i s c o s i t y increased r a p i d l y w i t h g e l a t i o n o c c u r r i n g i n 5-15 minutes. P o l y m e r i z a t i o n of 6. A sample (1-2 g) of J> was melted and heated a t 220 C f o r 48 hours. G e l a t i o n was extremely slow (30 hours) a t t h i s temperature. The polymeric m a t e r i a l was postcured at 240°C f o r 24 hours which enhanced the toughness of the material. Another sample of j$ was heated a t 240 C f o r 24 hours. G e l a t i o n had occurred a f t e r 6 hours a t t h i s temperature. e

e


3.

KELLER

AND GRIFFITH

Phthalocyanine

Resins

33

A m i x t u r e o f 6> ( 1 . 5 g , 3.3 mmol) a n d a s t o i c h i o m e t r i c amount of s t a n n o u s c h l o r i d e d i h y d r a t e ( 0 . 3 6 g , 1.6 mmol) was p l a c e d i n a t e s t t u b e . The monomer 6> m e l t e d a t 105-110°C. A t 170-175°C t h e s a l t d i s s o l v e d a n d t h e r e a c t i o n medium became g r e e n i m m e d i a t e l y . The t e m p e r a t u r e was i n c r e a s e d t o 215°C a n d t h e s a m p l e was h e a t e d a t t h i s t e m p e r a t u r e f o r 24 h o u r s . G e l a t i o n h a d o c c u r r e d a f t e r 15 m i n u t e s a t 215°C.


Acknowledgment We w i s h t o t h a n k D r . C. F. P o r a n s k i , J r . , N a v a l R e s e a r c h L a b o r a t o r y , f o r r e c o r d i n g a n d a n a l y z i n g t h e nmr s p e c t r a .

Literature 1. 2. 3. 4. 5. 6. 7. 8.

9. 10. 11.

12.

13.

14.

15. 16. 17.

Cited

V o g e l , H.; M a r v e l , C. S.; J. Polym. Sci., 1961, 50, 511. Kubota, T . ; N a k a n i s h i , R.; J. Polym. Sci., 1964, 2, 655. Hergenrother, P . M.; L e v i n e , H . M.; J. Polym. Sci., A 3 , 1965, 1665. K u r i h a r a , M.; Hagiwara, Y.; Polym. J.; 1970, 1, 425. K u r i h a r a , M.; Yoda, N.; J. Polym. Sci. ( Β ) , 1966, 4, 1 1 . Jones, J. I.; Ochynski, F . W.; Rackley, F . Α . ; Chem. and Ind., 1962, 1686. Varma, I. K.; G o e l , R. N.; Varma, D . S . ; J. Polym. Sci., 1979, 17, 703. Griffith, J . R . ; O'Rear, J. G.; Walton, T. R.; "Phthalonitrile Resin in Copolymers, P o l y b l e n d s , and Composites", Advanc. Chem. S e r . , 1975, 142, 458. Walton, T. R.; Griffith, J. R . ; A p p l i e d Polymer Symposium, 1975, 26, 429. Walton, T. R . ; Griffith, J. R . ; O'Rear, J. G.; Adhesion Science and Technology, 1975, 9b, 665. Walton, T. R.; Griffith, J. R . ; O'Rear, J. G.; 168th N a t i o n a l American Chemical S o c i e t y Meeting, Organic Coatings and Plastics P r e p r i n t s , Sept. 1974, 34, 446. Walton, T. R.; Griffith, J. R . ; O'Rear, J. G.; 174th N a t i o n a l American Chemical S o c i e t y Meeting, Organic Coatings and Plastics P r e p r i n t s , Sept. 1977, 37 ( 2 ) , 180. Keller, T. M.; Griffith, J. R . ; 176th N a t i o n a l American Chemical S o c i e t y Meeting, Organic Coatings and Plastics Pre -prints, Sept. 1978, 39, 546. Takekoshi, T . ; W i r t h , J. G.; Heath, D. R.; Kochanowski, J. E.; M a n e l l o , J. S . ; Webber, M . J.; 177th N a t i o n a l American Chemical S o c i e t y Meeting, Polymer P r e p r i n t s , April 1979, 20 (1), 179. W i l l i a m s , F . J.; Donahue, P . E.; J. O r g . Chem., 1977, 42, 3414. Beck, J. R . ; Sobizak, R. L.; Suhr, R. G.; Yahner, J. Α . ; J. Org. Chem., 1974, 39, 1839. R e l i e s , Η. M.; Orlando, C. M.; Heath, D. R.; Schluenz, R. W . ; M a n e l l o , J. S . ; Hoff, S . ; J. Polym. Sci., 1977, 15, 2441.


RESINS

34

FOR AEROSPACE

18. Radlmann, E.; Schmidt, W.; Nischk, G. E.; Makromol. Chem., 1969, 130, 45. 19. Govin, J. H.; Chem. Ind. (London), 1967, 36. 1525. 20. Spence, T. W. M.; Tennant, G.; J. Chem. Soc., P e r k i n Trans., 1972, 1, 835. 21. Beck, J . R.; J. Org. Chem., 1972, 37, 3224. 22. Beck, J. R.; Yahner, J. A.; J. Org. Chem., 1974, 39, 3440. 23. Knudsen, R. D.; Snyder, H. R.; J. Org. Chem., 1974, 39, 3343. 24. Bunnett, J. F.; Q. Rev., Chem. Soc., 1958, 12, 1. February 15,

1980.


RECEIVED


The Synthesis of a New Class of Polyphthalocyanine Resins - ACS

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