Abstract Ring opening copolymerization of ethylene brassylate (EB) and δ-valerolactone (δ-VL) with various feeding ratios catalyzed by triphenyl bismuth was performed to prepare poly(ethylene brassylate-co-δ-valerolactone) copolyesters. The reactivity ratios of EB and δ-VL were firstly determined to be r EB = 0.64 and r VL = 2.54 , respectively. Then the copolymerization kinetics was traced and microstructure analysis showed that the chain structure of copolyesters were rearranged towards complete random as a consequence of transesterification reaction. The resulting random copolymers were found to cocrystallize to exhibit isodimorphism phenomenon with a pseudo-eutectic point of melting temperatures and lattice spacings at 80 mol% δ-VL units. Moreover, the variation of the lattice spacings confirmed that the comonomer units have better miscibility in the case of incorporation of shorter units into longer unit crystal than the opposite case. Finally, the continuously tunable mechanical properties of these copolyesters showed a similar pseudo-eutectic behavior at the same eutectic point of isodimorphism, which indicated that the correlation between isodimorphism and mechanical properties depending on composition is highly significant.

中文翻译：

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乙二磺酸乙烯酯与δ-戊内酯的共聚制备机械性能连续可调的同型无规共聚酯

摘要 在三苯基铋的催化下，乙烯乙二酯（EB）和δ-戊内酯（δ-VL）在不同进料比例下开环共聚，制备聚（乙烯-乙二磺酸-共-δ-戊内酯）共聚酯。EB 和δ-VL 的反应性比首先确定为r EB = 0.64 和r VL = 2.54 。然后共聚动力学被追踪，微观结构分析表明，由于酯交换反应，共聚酯的链结构向完全无规方向重新排列。发现所得的无规共聚物共结晶以表现出具有假共晶点的熔融温度和晶格间距为 80 mol% δ-VL 单元的同二晶现象。而且，晶格间距的变化证实，与相反的情况相比，在将较短单元并入较长单元晶体的情况下，共聚单体单元具有更好的混溶性。最后，这些共聚多酯连续可调的机械性能在同二晶的相同共晶点处表现出类似的假共晶行为，这表明同二晶与机械性能之间的相关性取决于组成是非常显着的。