Amphiphilic triblock copolymers, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) as a hydrophobic block and poly(ethylene glycol) (PEG) as a hydrophilic block, were successfully synthesized, with an aim to broaden the potential application of PHBV in biomedical areas. Isophorone diisocyanate having two different reactive isocyanate groups was used as the coupling agent. Telechelic hydroxylated PHBV was prepared by alcoholysis reaction, isocyanate modified and finally reacted with PEG. Molecular weight of triblock copolymer increased with the increasing molecular weight of PHBV-diol and PEG. The length of the PHBV block and PEG block had a great influence on the crystallization behavior of the triblock copolymers. Thermal degradation temperature of PHBV segment enhanced greatly. The triblock copolymer showed a tendency toward formation of aggregation in aqueous solution with a critical aggregation concentration of 5.01×10-4 g·L-1, and the rod-shape assembly with a uniform hydrophilic shell might be employed as hydrophobic drug delivery systems.

中文翻译：

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聚（乙二醇）-嵌段-聚（3-羟基丁酸酯-co-3-羟基戊酸酯）-嵌段-聚（乙二醇）三嵌段共聚物的制备与表征

两性三嵌段共聚物，聚（3-羟基丁酸酯-co-3-羟基戊酸酯）（PHBV）作为疏水性嵌段和聚（乙二醇）（PEG）作为亲水性嵌段，已成功合成，目的是拓宽聚苯乙烯的潜在应用范围PHBV在生物医学领域。具有两个不同的反应性异氰酸酯基的异佛尔酮二异氰酸酯用作偶联剂。通过醇解反应制备异螯合羟基化的PHBV，将异氰酸酯改性，最后与PEG反应。三嵌段共聚物的分子量随PHBV-二醇和PEG分子量的增加而增加。PHBV嵌段和PEG嵌段的长度对三嵌段共聚物的结晶行为有很大的影响。PHBV链段的热降解温度大大提高。