REACTIVE BLENDING OF COMMERCIAL PET AND PC WITH FRESHLY ADDED CATALYSTS

Reactive blending of commercial poly(ethylene terephthalate) (PET) and bisphenol A polycarbonate (PC), with catalysts added in the form of p owder dispersed on the polymers just before melt mixing, was performed in a Brabender Plasticord 2000 apparatus at 275 degrees C. Catalytic activity of the catalysts freshly added to polymers was found to be mu ch higher as compared with that of the residues of the same type of ca talysts remaining in PET after its synthesis. Furthermore, the catalyt ic activity appeared to be strongly dependent on the structure of the ligand that influences the catalyst solubility in the polymer melt. N. m.r. spectroscopy, selective degradation of PC fragments, solubility t ests in methylene chloride and d.s.c. measurements made it possible to range the catalysts studied according to their catalytic activity. Co pyright (C) 1996 Elsevier Science Ltd.