Synthesis, characterization and thermal properties of hexaarmed star-shaped poly(3-caprolactone)-b-poly(D,L-lactide-co-glycolide)initiated with hydroxyl-terminated cyclotriphosphazene
作者：Weizhong Yuan, Xiaozhen Tang, Xiaobin Huang, Sixun Zheng
关键字：Phosphazene, Ring-opening synthesis, Star-shaped block copolymer
论文来源：期刊
发表时间：2005年
Hexakis[p-(hydroxymethyl)phenoxy]cyclotriphosphazene was prepared by the reaction of hexachlorocycltriphosphaneze with the sodium
salt of 4-hydroxybenzaldehyde and subsequent reduction of aldehyde groups to alcohol groups by using sodium borohydride. Hexaarmed
star-shaped hydroxyl-terminated poly(3-caprolactone) (PCL) were successfully synthesized via ring-opening polymerization of 3-
caprolactone (CL) with the above hydroxyl-terminated cyclotriphosphazene initiator and stannous octoate catalyst in bulk. The numberaverage
molecular weight of PCL linearly increased with the molar ratio of monomer to initiator. The star-shaped PCL with hydroxy end
groups could be used as a macroinitiator for block copolymerization with D,L-lactide (D,L-LA) and glycolide (GA) using stannous octoate
catalyst. IR, 1H NMR and GPC analysis showed the star-block copolymers were successfully synthesized and the molecular weights and the
unit composition of the star-shaped block copolymers were controlled by the molar ratios of D,L-LA and GA monomers to CL. The
copolymer presented a two-phase structure, namely, PCL crystalline and D,L-LAGA amorphous domains, which made the copolymer
different from linear PCL and star-shaped PCL in crystallinity and thermal behaviors.
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