23 Heat and Water Resistant Polyphenyl-as -triazines from Terephthalamidrazone FENG-CAI LU, LAN-MIN XING, and YU-LAN WANG Downloaded by UNIV OF NORTH CAROLINA on July 15, 2016 | http://pubs.acs.org Publication Date: August 12, 1982 | doi: 10.1021/bk-1982-0195.ch023
Institute of Chemistry, Academia Sinica, Beijing, China Six new relatively high molecular weight polyphenyl -as-triazines PPT (I)-(VI) were synthesized from terephthalamidrazone and different aromatic dibenzils. These polymers were characterized by thermogravimetric analysis, differential thermal analysis, elemental analysis and infra-red spectroscopy. A l l properties were determined by using specimens in the form of films and varnished wire. Experimental results showed that these polymers exhibited good thermal oxidative stability, hydrolytic stability, chemical stability and tensile strength at room temperature with the exception of polymer (VI). The films of polymer (I)-(V) suffered 4.30-5.31% weight loss after isothermal aging in air at 300°C for 200 hours. There were no changes in weight when these films were treated in water at 200°C for 30 hours. Wire coated with polymer (I) at room temperature in water has a resistance of 10 10 ohms. After i t was boiled in 40% sodium hydroxide solution for as long as 24 hours or submerged in water at 200°C for 100 hours, no change in insulation was detected. 11
12
S i x new r e l a t i v e l y h i g h molecular weight p o l y p h e n y l - a s - t r i azines PPT (I)-(VI) were prepared by s o l u t i o n cyclopolycondensat i o n o f terephthalamidrazone with v a r i o u s d i b e n z i l s as shown i n Eq ( I ) . The p o l y p h e n y l - a s - t r i a z i n e s i n t h i s paper are r e l a t i v e l y high molecular weight polymers c o n t a i n i n g 1 , 2 , 4 - t r i a z i n e s and aromatic n u c l e i i n the main polymer c h a i n s , η, , were between 1.39-2.16 d l / g ( 0.5% s o l u t i o n i n c r e s o l a t 25 C ) due t o h i g h p u r i t y o f the two monomers concerned. A yellow, transparent, f l e x i b l e f i l m was prepared from each o f these polymer s o l u t i o n s and varnished wire was obtained by c o a t i n g the m e t a l l i c wire n
0097-6156/82/0195-0297$06.00/0 © 1982 American Chemical Society
Butler and Kresta; Cyclopolymerization and Polymers with Chain-Ring Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1982.
POLYMERS
298
WITH CHAIN-RING STRUCTURES a
1
1
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with the polymer s o l u t i o n . With the exception o f Π . ^ * pro p e r t i e s o f these polymers were measured on such f i l m s and v a r n i shed wire.
Pure terephthalamidrazone which can be used as one o f mono mers i n the s y n t h e s i s o f s i x polymers were prepared by an improv ed method. I t was found t h a t the o x i d i z i n g agent — selenium oxide ( S e 0 ) commonly used i n the s y n t h e s i s o f d i b e n z i l s was not s a t i s f a c t o r y . In our p r e v i o u s work [1], selenium oxide was r e p l a c e d by dimethyl s u l f o x i d e (DMSO) i n the presence o f hydrobromic a c i d . T h i s system was proved t o be a s i m p l i f i e d and l e s s expensive procedure, which gave product o f high p u r i t y . Wrasidlo and Augl [2] r e p o r t e d t h a t 1 , 4 - b i s ( p h e n y l g l y o x a l y l ) benzene was prepared from 1,4-phenylene d i a c e t i c a c i d by r e a c t i n g with t h i o n y l c h l o r i d e , followed by F r i e d e l - C r a f t s r e a c t i o n , and o x i d a t i o n by S e 0 . However, we e a s i l y prepared 1,4-bis(phenylglyoxalyl)benzene by u s i n g 1,4-dicyanobenzene as the s t a r t i n g m a t e r i a l which r e a c t e d with Grignard reagent o f benzyl c h l o r i d e and was then o x i d i z e d by dimethyl s u l f o x i d e i n the presence o f hydrobromic a c i d . The other aromatic d i a c e t y l compounds were a l s o o x i d i z e d by dimethyl s u l f o x i d e . In the l i t e r a t u r e [3], the s o l vent used f o r the r e a c t i o n (4) was e t h e r . In our p r e v i o u s work, mixed s o l v e n t (benzene and tetrahydrofuran) was used. As a r e s u l t , t h i s improvement o f f e r e d the advantage f o r l a r g e s c a l e p r e p a r a t i o n . 2
2
The routes used t o prepare terephthalamidrazone and l ^ - b i s (phenylglyoxalyl)benzene a r e shown i n Eq. ( 2 ) - ( 5 ) :
N C - ^ C N -I- C H O H - ~ C ^ - & ^ ? - O C H H
2
5
2
C ^0-?-^^OC H *H N+! N — 2
2
5
2
2
2
5
(2)
H N4^-@5^H-NH (3) 2
Butler and Kresta; Cyclopolymerization and Polymers with Chain-Ring Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1982.
2
23.
L UE T AL.
Heat and Water Resistant Polyphenyl-zs-triazines
@Οφ*Ά
Downloaded by UNIV OF NORTH CAROLINA on July 15, 2016 | http://pubs.acs.org Publication Date: August 12, 1982 | doi: 10.1021/bk-1982-0195.ch023
NC®CN +
—
®c -?-®-P-CH -® H2
2
299
Experimental Monomers. D i e t h y l t e r e p h t h a l i m i d a t e was prepared by mixing 7.68 g ( 0.06 mole ) o f 1,4-dicyanobenzene with 9 ml absolute e t h y l a l c o h o l and 330 ml anhydrous 1,4-dioxane and by p a s s i n g d r y hydrogen c h l o r i d e gas i n t o the s o l u t i o n a t 0-5 C u n t i l s a t u r a t i o n . Then the r e a c t i o n v e s s e l was c l o s e d , and maintained a t t h i s tem perature f o r 5 days t o i n s u r e completion o f r e a c t i o n . The r e s u l t i n g white s o l i d was f i l t e r e d , washed and air^-dried t o y i e l d 15.5 g ( 90% y i e l d ) o f d i e t h y l t e r e p h t h a l i m i d a t e d i h y d r o c h l o r i d e . A f t e r n e u t r a l i z i n g t h i s d i h y d r o c h l o r i d e with 15-18% potassium hydroxide, the product was f i l t e r e d , washed with water, and d r i e d . The white s o l i d ( 10.5 g ) was then t r e a t e d with petroleum ether, and d i e t h y l t e r e p h t h a l i m i d a t e was formed as white c r y s t a l l i n e plates, mp. 110-111°C ( L i t . [4],rap.110°C ) . Analysis: i6 2°? CalcdT C7 65.44; H, 7.32; N, 12.72% Found: C, 65.45; H, 7.30; N, 12.69% Terephthalamidrazone was prepared by r e a c t i n g 6.6 g ( 0.03 mole ) o f d i e t h y l t e r e p h t h a l i m i d a t e d i s s o l v e d i n 50 ml a b s o l u t e e t h y l a l c o h o l with 5.01 g ( 90%, 0.09 mole ) o f hydrazine hydrate. T h i s r e a c t i o n took p l a c e i n a corked v e s s e l a t room temperature, and l i g h t y e l l o w s o l i d g r a d u a l l y s e t t l e d down. The y e l l o w s o l i d was then f i l t e r e d , washed with anhydrous ether, and d r i e d t o y i e l d 5.06 g ( 87.8% y i e l d ) o f crude product. I t was r e c r y s t a l l i z e d from p y r i d i n e under Ν . A f t e r d r y i n g , 3.5 g ( 60% y i e l d ) o f t e r e phthalamidrazone which decomgosited between 225-227 C ( L i t . [5], Decomposition p o i n t : 223-225 C ) was y i e l d e d . Analysis: C Η Ν C a l c d : C, 49.98; H, 6.29; N, 43.72% Found: C, 50.36; H, 6.31; N, 43.36% l , 4 - B i s ( p h e n y l g l y o x a l y l ) b e n z e n e was prepared as p r e v i o u s l y r e p o r t e d [1] . 1,4-Bis(phenyl acetyl)benzene was obtained from the r e a c t i o n o f 1,4-dicyanobenzene w i t h Grignard reagent o f b e n z y l c h l o r i d e , mp. 175-177 C ( 54.4% y i e l d ), and r e c r y s t a l l i z e d from e t h y l a c e t a t e t o y i e l d white o r l i g h t y e l l o w c r y s t a l s , mp. 178-180 C, Analysis: C Η Ο C a l c d : C, 84.00; H, 5.94% Found: C, 83.90; H, 5.93% F i n a l l y , 1,4-bis(phenyl acetyl)benzene was r e a d i l y o x i d i z e d by dimethyl s u l f o x i d e i n the presence o f hydrobromic a c i d t o form 1,4-bis(phenylglyoxalyl)benzene, which was r e c r y s t a l l i z e d from η-butyl a l c o h o l , mp. 126-127°C ( L i t . [6], mp, 125-126°C )· c
H
N
1 2
Q
Butler and Kresta; Cyclopolymerization and Polymers with Chain-Ring Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1982.
POLYMERS WITH CHAIN-RING STRUCTURES
300
Analysis: C Η Ο Calcd: C, 77.18; H 4.12% Found: C, 77.06; H, 4.13% In the s y n t h e s i s o f d i b e n z i l s ( I I , I I I , V I ), the d i a c e t y l compounds were prepared f o l l o w i n g a known procedure [3] and were then o x i d i z e d by dimethyl s u l f o x i d e . 4
f
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© C H ^ - A r J - C H ^ Ar=
ΦθΦ ft
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The d i b e n z i l s ( IV, V ) were prepared according to R e l i e s et a l . [7]. The p r o p e r t i e s o f a l l the d i b e n z i l s are shown i n Table I . Model Compounds. P r i o r to polymer s y n t h e s i s , the model com pound I and II as shown i n Eq. (6) were prepared s e p e r a t e l y by r e f l u x i n g ( 4 hours ) 0.192 g ( 0.001 mole ) of terephthalamidra zone with 0.42 g ( 0.002 mole ) o f b e n z i l or 0.572 g ( 0.002 mole ) of 4-phenylbenzil i n the presence of anhydrous e t h y l a l c o h o l . The cooled s o l u t i o n s gave q u a n t i t a t i v e y i e l d o f p a l e yellow s o l i d s which were r e c r y s t a l l i z e d from dimethyl formamide r e s p e c t i v e l y , mp. 320-321°C; 329-332°C. Analysis : 3 6 CaS3f" . 79.98; H, 4.47; N , 15.54% Found: ι 80.01; H, 4.44; N , 15.62% Analysis: C 32 6 H
N
Calcd: 4 Ç
Found:
HN
NM
(6)
The IR s p e c t r a showed absorptions o f 1 , 2 , 4 - t r i a z i n e a t 1445, 1385-1390 and 1020 cm [8] and are shown i n F i g 1,2, Polymers. The polymers were prepared by the f o l l o w i n g pro
