Unusual Fractional Crystallization Behavior of Novel Crystalline/Crystalline Polymer Blends of Poly(ethylene suberate) and Poly(ethylene oxide) with Similar Melting Points
Unusual Fractional Crystallization Behavior of Novel Crystalline/Crystalline Polymer Blends of Poly(ethylene suberate) and Poly(ethylene oxide) with Similar Melting Points
复制标题
熔点相似的聚辛二酸乙二酯和聚环氧乙烷的新型结晶/结晶聚合物共混物的异常分级结晶行为
DOI：
10.1021/ma502019x
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发表时间：
2014
期刊：
影响因子：
5.5
通讯作者：
Qiu Zhaobin
中科院分区：
文献类型：
--
作者：
Weng Mengting;Qiu Zhaobin
采用溶液-浇铸法制备了可生物降解聚琥珀酸乙二醇酯(PESub)和生物相容聚氧乙烷(PEO)的新型结晶/结晶聚合物共混物。两组分的基本热性能，包括玻璃化转变温度和熔点，都非常接近。由于没有检测到明显的相分离，这两个组分是可混溶的，形成了两种结晶聚合物的新型可混溶聚合物混合物。PESub/PEO共混物在不同的过冷度下表现出两到三个结晶放热。这种复杂的结晶行为归因于共混物中次要成分的分离结晶的发生。根据共混物的组成，共混物的主要成分首先结晶，次要成分随后结晶。在主要成分的晶化过程中，非晶次成分被完全包含在主要成分的片层间区域，或者大部分非晶次成分被逐出片层区域，而只有少数非晶次成分被结合在主要成分的片层之间。在这两种情况下，由于主要成分片层的限制效应，次要成分的分步结晶在大过冷度下发生。在本工作中，当PESub或PEO的含量较低时，其在大过冷度下可能发生分步结晶。PESub/PEO共混物可能是第一个在大过冷度下各组分在低含量时发生分离结晶的模型，从而为研究可相容结晶/结晶聚合物共混物独特的结晶形态和结晶行为提供了一个难得的体系。这样的研究对于从理论和实践角度更好地理解结晶聚合物共混物的结晶形态和结晶行为都是非常有趣和具有挑战性的。
Novel crystalline/crystalline polymer blends of biodegradable poly(ethylene suberate) (PESub) and biocompatible poly(ethylene oxide) (PEO) were prepared through a solution and casting method. The basic thermal properties, including both glass transition temperature and melting point, of both of the components are very close to each other. The two components are miscible as no obvious phase separation can be detected, forming novel miscible polymer blends of two crystalline polymers. PESub/PEO blends show two or three crystallization exotherms at different supercoolings. The complex crystallization behaviors are attributed to the occurrence of the fractional crystallization of the minor component of the blends. Depending on the blend composition, the major component of the blend crystallizes first and the minor component crystallizes later. During the crystallization of the major component, the amorphous minor component is completely included the interlamellar region of the major component or most of the amorphous minor component is expelled out of the interlamellar region while only a few is incorporated between the lamellae of the major component. In both cases, the fractional crystallization of the minor component occurs at large supercooling because of the confinement effect of the lamellae of the major component. In the present work, the fractional crystallization of PESub or PEO may occur at large supercooling when its content is low. PESub/PEO blends may be the first model that the fractional crystallization of each component occurs at large supercooling when its content is low; thus, they provide a rare system to study the unique crystalline morphology and crystallization behavior of miscible crystalline/crystalline polymer blends. Such research is very interesting and challenging for a better understanding of the crystalline morphology and crystallization behavior of crystalline polymer blends from both academic and practical viewpoints.