Block copolymer formation from the melt reaction between polycarbonate andpoly(ethylene-co-butylene) diol

The block copolymer formation from the exchange reaction between polycarbon ate (PC) and poly(ethylene-co-butylene) diol (POH) occurring during melt mi xing was studied. The exchange reaction proceeded by the attack of active c hain ends of hydroxyl-terminated POH on the inner carbonate groups of PC. T he reaction was accelerated in basic condition in the presence of a hindere d amine. The formation of block copolymer was confirmed by H-1-NMR analysis . The proceeding of the exchange reaction was analyzed with IN spectrometry by measuring the absorbance at 285 nm of the less-reactive phenolic end gr oup of PC oligomers produced. The reaction was terminated when the hydroxyl end groups of POH were completely consumed. It was found from the analyses by GPC and DSC that the exchange reaction between PC and POH takes place r ather uniformly by random scission of the chain. The block copolymer obtain ed here will be employed as a compatibilizer of PC/polyolefin blends in a f uture study. (C) 2001 John Wiley & Sons, Inc.