writer：Lang, Meidong, and Chu, Chih-Chang
keywords：biodegradable; photocrosslinking; poly(?-caprolactone)s; ring-opening polymerization; functionalization of polymers
source：期刊
Issue time：2002年

The purpose of this research was to synthesize and characterize a novel class of four-arm, star-shape biodegradable polymers having double-bond functionality as a precursor for free-radical polymerization, with unsaturated monomers or macromers or photocrosslinking for network formation. The synthesis involved two basic steps. First, hydroxyl-functionalized four-arm poly(_-caprolactone) s (PPCL-OH) were synthesized by the ring-opening polymerization of _-caprolactone in the presence of pentaerythritol and stannous octoate. Second, double-bond–functionalized four-arm poly(_-caprolactone)s (PPCL-Ma) were synthesized by reacting PPCL-OHwith maleic anhydride in the melt at 130°C. Quantitative conversion of hydroxyl functionality in PPCL-OH to double-bond functionality was achieved for low molecular weight PPCL-OH. Both the PPCL-OH and the PPCL-Ma were characterized by FTIR, 1H-NMR, 13C-NMR, SEC, and DSC. The capability of the double-bond–functionalized four-armpoly(_-caprolactone)s (PPCL-Ma) to form network structures was preliminarily shown by photocrosslinking PPCL-Ma.