POLY(ETHER ESTER) NETWORKS PREPARED BY POLYCONDENSATION OF R,S-MALIC ACID WITH DIOLS AND POLYETHER ALCOHOLS IN THE PRESENCE OF N,N'-DICYCLOHEXYLCARBODIIMIDE

The possibility of preparing polyester and poly(ether-ester) networks from R,S-malic acid and diols or poly(ether alcohol)s by polycondensat ion was investigated. The reactions were carried out in tetrahydrofura n in the presence of N,N'-dicyclohexylcarbodiimide and p-toluenesulfon ic acid and pyridine as catalyst. I.r., H-1 n.m.r. and mass spectra of the crosslinked products obtained, confirmed their ester and ether-es ter structure. The dependence of swelling and some thermodynamic param eters upon the kind of alcohol used was established. The new synthesiz ed crosslinked polymers, which can be swelled in a variety of solvents and are thermohydrolytically unstable, can be used as biodegradable c arriers for drugs and microelements.