ALTERNATING POLYESTERAMIDES BASED ON 1,4-BUTYLENE TEREPHTHALAMIDE - 1- SYNTHESIS OF THE BISESTERDIAMIDE

The bisesterdiamide T4T dimethyl tone and a half repeat units of 1,4-b utylene terephthalamide, nylon-4,T) (benzoic acid, 4,4'-[1,4-butanediy lbis(iminocarbonyl)]bis-, dimethyl ester, CAS no. 1028 10-33-3) has be en synthesized from an excess of dimethyl terephthalate and 1,4-butane diamine. Lithium methanolate was used as a catalyst. Different solvent s have been used to optimize the yield and purity. A pure product coul d be obtained by recrystallization from hot NMP. D.s.c. and n.m.r. ana lyses were used to determine the purity of the product. The melting te mperature of the T4T dimethyl (T-m = 265 degrees C) decreased with inc reasing loss of uniformity. The T4T dimethyl showed a transition in th e crystalline structure upon heating at 160-175 degrees C. (C) 1998 Pu blished by Elsevier Science Ltd. All rights reserved.