Polyimidazolinones via Thermal Cyclodehydration of Polyamides

Chapter 9

Polyimidazolinones via Thermal Cyclodehydration of Polyamides Containing α-Amino Acid Units 1

1

1

Jerald K. Rasmussen , Larry R. Krepski , Steven M . Heilmann , Kumars Sakizadeh , Dean M . Moren , Howell K. Smith, II , and Alan R. Katritzky 1

1

1

Downloaded by UNIV OF SYDNEY on April 3, 2018 | https://pubs.acs.org Publication Date: December 22, 1988 | doi: 10.1021/bk-1988-0364.ch009

2

1

Corporate Research Laboratories, 3M Company, 201-2N-20, 3M Center, St. Paul, M N 55144 Department of Chemistry, University of Florida, Gainesville, FL 32611 2

Polyamides containing α-aminoacid units are readily obtained by reaction of bisazlactones (2-oxazolin-5ones) with diamines. When polyamines such as diethylenetriamine (DETA) or triethylenetetramine (TETA) are used as the diamine component, the resultant polyamides readily cyclodehydrate above 200°C to produce polymers containing 2-imidazolin-5one units in the backbone. Polyamides derived from simple diamines (e.g. 1,6-hexanediamine) cyclodehydrate only in the presence of a suitable catalyst. Carboxylate salts and certain Lewis acids have been found to be efficient catalysts for this transformation. Polyamides and p o l y e s t e r a m i d e s having a r e g u l a r arrangement o f d i a c i d and α - a m i n o a c i d u n i t s d e r i v e d from b i s a z l a c t o n e s 1 were i n i t i a l l y r e p o r t e d i n 1943 {I) (Equation 1 ) . Although r e l a t i v e l y l i t t l e i n f o r m a t i o n jDn polymer p r o p e r t i e s was g i v e n , b i s ( s e c o n d a r y amines) (2, X = N R ) were recommended as monomers because o f t h e o c c u r r a n c e o f secondary r e a c t i o n s w i t h p r i m a r y amines. Cleaver and P r a t t subsequently described (2) s o l u t i o n polymerizations using several diamines, i n c l u d i n g d i p r i m a r y amines, i n g r e a t e r detail. They c h a r a c t e r i z e d t h e polyamides 3 as b e i n g amorphous, h i g h m e l t i n g , d i f f i c u l t l y s o l u b l e m a t e r i a l s which decomposed a t t h e i r melting points. Korshak and coworkers l a t e r r e p o r t e d (3) the p r e p a r a t i o n o f s e v e r a l polyamides 3 d i s p l a y i n g c r y s t a l l i n i t i e s o f from 10-55%. Ueda and coworkers found (4) that solubijities o f t h e r e s u l t a n t p o l y a m i d e s were i m p r o v e d when and R were phenyl groups. A s e r i e s o f p o l y a m i d e s 3 were a l l f o u n d t o decompose a t around 250°C as measured by TGA. More r e c e n t l y , a v a r i e t y o f f i l m - and f i b e r - f o r m i n g p o l y a m i d e s 3 b a s e d upon n a t u r a l l y o c c u r r i n g α - a m i n o a c i d s have been d e s c r i b e d (5>) which a r e biodegradable. 5

J

Polyamides

containing

#-aminoamide

linkages

have

0097-6156/88/0364-0119S06.00/0 © 1988 American Chemical Society

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

been

120

CHEMICAL REACTIONS ON POLYMERS

reported to cyclodehydrate t o the corresponding 2-imidazoline u n i t s upon h e a t i n g a t t e m p e r a t u r e s i n e x c e s s o f 275°C (6) (Equation 2). The c u r r e n t work was i n i t i a t e d as p a r t o f a program d e s i g n e d t o d e v e l o p new polymers i n c o r p o r a t i n g h e t e r o c y c l i c n u c l e i . Our c o n t i n u i n g i n t e r e s t i n the u t i l i z a t i o n o f a z l a c t o n e s i n polymer c h e m i s t r y ( 7 - 9 ) prompted us t o combine the c o n c e p t s o u t l i n e d i n E q u a t i o n s 1 and 2 i n an attempt t o p r e p a r e polymers c o n t a i n i n g a r e g u l a r arrangement o f amide and i m i d a z o l i n e l i n k a g e s .


Experimental All s o l v e n t s and r e a g e n t s were r e a g e n t grade o r were purified before use. IR s p e c t r a were r e c o r d e d on a P e r k i n - E l m e r 9 8 3 ; NMR s p e c t r a were r e c o r d e d a t 200 MHz on a V a r i a n X L - 2 0 0 using t e t r a m e t h y l s i l a n e as an i n t e r n a l r e f e r e n c e . Inherent v i s c o s i t i e s were determined a t a c o n c e n t r a t i o n o f 0.5g/dL u s i n g a Canon-Fenske v i s c o m e t e r a t 30°C. Monomer and polymer s y n t h e s i s has r e c e n t l y been d e s c r i b e d ( 1 0 ) . C a t a l y s t Study. E q u i v a l e n t amounts o f p-phenylenebis(4,4dimethyl-2-oxazolin-5-one) (2) and J e f f a m i n e D-2000 ( p o l y o x y p r o p y l e n e d i a m i n e from Texaco Chemical C o . , amine e q u i v . weight 1023) were mixed w i t h 5 mole % o f the d e s i r e d c a t a l y s t . The s t i r r e d m i x t u r e was h e a t e d a t 240°C u n d e r a r g o n f o r 30 m i n u t e s , then an a d d i t i o n a l 1.5 hours under vacuum (N N^J . — • — • " \ V R ' - ^ P 'R Ο

R2 1

R (COOH)

121

Polyimidazolinones

D

2

2

V

2

(1) 2

2

Ο R Ο Ο R Ο > Il I II II I II C - CNHCRCNHC - CXR XI I R R3 y

4

HXR XH

4


3

? - CNHCH CH NH - R 2

Δ 2

.N-, R—ν J *| 1

•

2

-H 0 2

CH3 C

(2)

CH3

" 1 \i&*àïdF 3

P

CH

C H

3

+

H N(CH ) NH(CH ) NH(CH ) NH 2

Ο

3

Ο

2

CH

2

2

2

2

2

2

3

- C H N H ( C H ) NHC - C - NHC - ( C H ^ C N H C - C N H ( C H ) N H C H " Ι 2

2

2

2

Ο

CH

2

2

CH Ο

3

3

6

-CH NH(CH ) N — C - ( C H ) - C — N ( C H ) N H C H 2

2

2

2

C 0

Ν

3

2

N

A CH

4

A CH

3

CH3

2

2

C. 0

CH

3

Scheme 1

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

122

CHEMICAL REACTIONS ON POLYMERS


r e a c t i o n s of c e r t a i n b i s a z l a c t o n e s , e s p e c i a l l y those having hydrogen atoms i n the 4 - p o s i t i o n , l e d us t o c o n s i d e r p r e p a r a t i o n of polyimidazolinones from the acyclic precursors of the b i s a z l a c t o n e s (Scheme 2 ) . Initially, Ν,Ν'-azeleoylbis(

Polyimidazolinones via Thermal Cyclodehydration of Polyamides

Recommend Documents