PARTIALLY SELECTIVE METHANOLYSIS OF SEBACIC UNITS IN BIODEGRADABLE MULTICOMPONENT COPOLYESTERS

The composition and molar masses of equimolar multicomponent copolyest ers, obtained from 1,4-butandiol and mixtures of succinic, adipic. seb acic, and terephthalic acids were characterized by C-13 NMR, size excl usion chromatography (SEC), matrix assisted laser desorption ionizatio n-time of flight mass spectroscopy (MALDI-TOF-MS), and viscosimetry. T hese copolyesters were subjected to partial methanolysis, and the comp osition and sequence of the oligomers obtained in the methanolysis wer e determined by the analysis of their fast atom bombardment (FAB-MS) m ass spectra. The comparison of the composition data obtained by FAB-MS and C-13 NMR indicates that for copolymers containing sebacic units t he methanolysis is a partially selective process, and that oligomers c ontaining sebacic units accumulate in the residue.