聚酯／改性共聚酯共混体系的相分离及其共混纤维的结构和性能

本文研究聚酯(PET)和含3.5-二甲酸苯磺酸钠(SIPM)结构单元的改性共聚酯(PEI)的共混体系。差示扫描量热分析,X射线衍射分析,染色后的透射和扫描电镜照片等均表明该体系是一个热力学不相溶的体系。在加工成形过程中,特别是在结晶过程中,富PEI相中的SIPM结构单元被排斥在晶格之外形成集簇形态,利用这种相分离的结构形态以及改性共聚酯优先水解的机理,PET/PEI共混纤维经碱水解处理后可制得微孔型的高吸水吸湿纤维。本文讨论了相分离结构对该微孔型纤维的微孔尺寸分布,吸湿保水性能以及纤维力学性能的影响。

Studies on Phase Separation of Polyester/Copolyester Blends and the Relationship of Structure and Properties of the Blends Fibers

In this paper the blend systens of polyester (PET) and copolyester (PEI) containing the structural units of dimethyl-3,5-sodiosulfoisophthalate (SIPM) are investigated in detail. By using diffrential scanning calorimetry, x-ray diffraction analysis, transmission and scanning electron microscopy, etc, it is shown that the PET/PEI blends are of a thermodynamically immiscible system. During the processing and fomation, especially during crystallization, the SIPM structural units in the PEI-rich phase are excluded from the crystal lattice and tend to gathering together as some clusters.By taking advantage of this kind of phase separation morphology as well as the mechanism of preferential hydrolysis of the copolyester, the microporous PET / PEI blend fibers of high wettblilty and high water-retention property can be obtained from the alkakine-hydrolysis treated PET/PEI blend fibers. The effects of the phase separation structure on the pore size distribution, water retention property, wettability as well as the mechanical properties of the microporous PET / PEI blend fibers are also discussed.