NONLINEAR BIODEGRADABLE POLYANHYDRIDES SYNTHESIZED FROM NATURAL FATTY-ACIDS THROUGH A NEW WAY

Ricinoleic acid was esterified by fatty diacid chlorides to yield inte rmediate diacids, which were next converted to corresponding polyanhyd rides by vacuum-melt polycondensation. The intermediates and polymers were characterized by means of H-1 NMR, IR spectroscopy, differential scanning calorimetry (DSC), X-Ray diffraction and light scattering. Th e optimized reaction conditions of melt polycondensation were investig ated and copolyanhydride with molecular weight (weight average) up to 1.38x10(5) and intrinsic viscosity of 126 cm(3)/g was obtained. DSC an d X-ray diffraction analysis showed that the synthesized copolyanhydri des exhibited much lower crystallinity and improved thermal properties in comparison with aliphatic linear homopolyanhydrides.