활성 디아실 유도체를 이용한 폴리아미드 및 폴리에스테르의 합성

Synthesis of Polyamides and Polyesters from Active Diacyl Derivatives

New active dithioester derivatives from 2-mercaptobenzothiazole and 2-mercaptobenzoxazole were prepared for use in polymide and polyester syntheses. Solution polycondensation of the new dithioesters, 2,2'-(isophthaloyldithio) bisbenzothiazole, S,S'-bis(2-benzoxazoyl) dithioisophthalate, with diamines and diols in aprotic solvents took place at relatively low temperature yielding polyamides and polyesters, respectively, with good yield. The effects of solvent, temperature, and additive were studied. The high reactivity of these active thioesters is discussed in relation to the electron-withdrawing effect on the leaving group and intramolecular general-base catalysis. The interfacial polycondensation in a chloroform-water system was also successful for polyamide and plyester formation. Prior to polymer syntheses, the aminolysis and alcoholysis of active monthioesters were carried out as a model compound study.