Abstract Polyethylene glycol with average molar mass of 1,450 Da (PEG-1450) was treated with equivalent amount of sodium hydride to convert hydroxy groups to sodium alkoxide. Assuming the PEG oligomer with alkoxy end-groups as a macroinitiator, anionic ring-opening polymerization of some lactones (β-propiolactone, α-methyl-β-propiolactone, δ-valerolactone and ε-caprolactone) with different ring sizes were performed to obtain the ABA-type poly(ester-ether-ester) block copolymers. Copolymers with various compositions were obtained with high yields. Spectroscopic and thermal characterization of the copolymers were performed by using DSC, TGA, FT-IR, and 1H-NMR spectroscopy. Formation of the block copolymers and their mass distributions were determined by MALDI mass spectrometry. Structural analyses of the copolymers revealed that chain extensions increased in order of α-methyl-β-propiolactone, β-propiolactone, δ-valerolactone and ε-caprolactone.

中文翻译：

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ABA型聚（酯-醚-酯）嵌段共聚物的合成与表征

摘要 平均摩尔质量为 1,450 Da 的聚乙二醇 (PEG-1450) 用等量的氢化钠处理，将羟基转化为醇钠。假设具有烷氧基端基的 PEG 低聚物作为大分子引发剂，对一些不同环大小的内酯（β-丙内酯、α-甲基-β-丙内酯、δ-戊内酯和ε-己内酯）进行阴离子开环聚合，得到ABA型聚（酯-醚-酯）嵌段共聚物。以高产率获得了具有各种组成的共聚物。通过使用 DSC、TGA、FT-IR 和 1H-NMR 光谱对共聚物进行光谱和热表征。嵌段共聚物的形成及其质量分布由MALDI质谱法测定。