Abstract In this article, two series of ABA triblock copolyesters composed of poly( l -lactide) A hard blocks and odd-odd aliphatic polyesters as B soft midblock were prepared and compared by various techniques. The results showed that the block structures could be formed without any detectable transesterification, and the composition and molecular weight of the triblock copolyesters could be well controlled by adjusting the feeding ratio of l -lactide monomer to the polyester macroinitiator. It was found that the thermal properties, crystal structure, and spherulitic morphology of the triblock copolyesters depended on the composition and block length. The impact of amorphous and crystalline midblocks on the mechanical properties was compared and discussed. The triblock copolyesters composed of crystalline midblock showed similar ultimate stress and elongation, but higher tensile modulus and yield stress, in comparison with analogous containing amorphous midblock. The triblock copolyester composed of short PLLA hard block and amorphous aliphatic polyester soft midblock displayed typical elastomeric behavior without yield, which is a promising aliphatic polyester thermoplastic elastomer.

中文翻译：

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由聚 (l-丙交酯) A 硬嵌段组成的 ABA 三嵌段共聚酯：无定形和结晶脂肪族聚酯作为 B 软嵌段的比较研究

摘要 本文制备了以聚丙交酯A硬嵌段和奇数脂肪族聚酯为B软中嵌段的两个系列ABA三嵌段共聚酯，并通过各种技术进行了比较。结果表明，可以在没有任何可检测到的酯交换的情况下形成嵌段结构，并且可以通过调节 l-丙交酯单体与聚酯大分子引发剂的进料比例来很好地控制三嵌段共聚酯的组成和分子量。发现三嵌段共聚酯的热性能、晶体结构和球晶形态取决于组成和嵌段长度。比较和讨论了无定形和结晶中间嵌段对机械性能的影响。与包含无定形中间嵌段的类似物相比，由结晶中间嵌段组成的三嵌段共聚酯显示出相似的极限应力和伸长率，但拉伸模量和屈服应力更高。由短 PLLA 硬嵌段和无定形脂肪族聚酯软中间嵌段组成的三嵌段共聚酯表现出典型的弹性行为，没有屈服，是一种很有前途的脂肪族聚酯热塑性弹性体。