SYNTHESIS AND CHARACTERIZATION OF ALPHA-HYDROXY, ALPHA-THIOL AND ALPHA-CHLOROFORMYL OLIGOMERS OF POLY(BUTYLENE TEREPHTHALATE)

alpha-Hydroxy and alpha-chloroformyl oligomers of poly(butylene tereph thalate) (PBT) were prepared in 1,1,2,2-tetrachloroethane by condensin g terephthaloyl chloride and 1,4-butanediol and using benzoyl chloride and 4-hydroxybutyl benzoate as chain limitator. The average molecular weight was determined by H-1 NMR analysis, and thermal properties wer e assessed by differential scanning calorimetry (DSC). Preparation of alpha-thiol oligomers of PBT was also investigated by esterification o f alpha-hydroxy oligomers with thioglycolic acid and using p-toluenesu lfonic acid as catalyst. The DSC and TGA analyses pointed out that the introduction of a thiol group by esterification has no influence on t he thermal properties of the PBT oligomers.