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聚合物的结晶过程和最终凝聚态结构直接影响材料的加工使用性能.作为高分子材料的最大品种,聚烯烃由于分子量大,分子量分布较宽,结晶过程中形成多种亚稳态,因而从分子水平上阐明其结晶机理存在困难.与聚乙烯链结构相似的长链正烷烃可作为聚烯烃的模型化合物,研究其受限结晶行为能为复杂的聚合物受限结晶提供理想的模型体系.长链正烷烃的受限空间可以分为一维受限薄膜、二维受限微孔、三维受限微乳液或微胶囊等.相对于本体,长链正烷烃在每个受限体系中的结晶行为各不相同,这主要来源于受限体系对成核、结晶以及相转变的影响.本文重点综述了长链正烷烃在3种受限体系中的结晶特点,并结合各个体系中聚合物的结晶特点,阐述了长链正烷烃作为聚合物模型化合物的合理性.
As the largest variety of polymer materials, polyolefins, due to their large molecular weight, broad molecular weight distribution and various metastable states in the crystallization process, can be obtained from the molecular structure of the polymer and the final condensed state structure, It is difficult to elucidate the mechanism of crystallization at a level.Long-chain n-alkanes with similar structure to polyethylene chain can be used as model compounds for polyolefin and its limited crystallization behavior can provide an ideal model system for complex polymer limited crystallization. The restricted space of n-alkanes can be divided into one-dimensional constrained film, two-dimensional constrained micropore, three-dimensional constrained microemulsion or microcapsule, etc. Compared with the bulk, the long-chain n-alkane crystallizes in each constrained system Behave differently, mainly from the restricted system on the nucleation, crystallization and phase transition.This article focuses on the long-chain n-alkanes crystallization characteristics of the three restricted systems, combined with the polymer in each system Crystallization characteristics, expounded the rationality of long chain n-alkanes as polymer model compounds.