The improvement of gel spinning fibers as clothing materials

随着近年来高分子科学的迅猛发展，人们对合成纤维进行了大量的研究，以生产具有不同性能特征的合成纤维。为了制备高强度高模量的聚烯烃、聚酰胺、聚酯和纤维素纤维，本文主要研究了分子量对拉伸性能的影响。特别注意的是形态性能，因为它们对机械和热性能有显著的影响。在本研究中，阐明了半结晶聚合物的形态和力学性能。更准确地说，(1)聚乙烯（PE）和聚丙烯（PP）在熔点附近的晶格模量与温度无关，但它们的杨氏模量随着温度的升高而降低。这是由于它们的结晶度随着温度的升高而降低。(2) x射线衍射测得的晶格模量和线性热膨胀系数与一般聚合物体系的本征晶格模量和系数不同，在一般聚合物体系中，取向晶体层被取向非晶相包围。(3) PE和PP晶体分散的来源取决于它们自身的形态。即晶体色散的活化能随着拉伸比的增大而降低。(4)在干燥的凝胶膜拉伸过程中，用过氧化二醇进行化学反应，使PE交联。当杨氏模量为100 GPa时，其耐高温性能显著提高。

In accordance with the recent dramatic development of polymer science, a number of researches have been carried out to produce synthethic fibers with different performance characteristics. The present studies deal with primarily with the investigation of the influence of molecular weight on drawability in order to prepare high strength and high modulus fibers of poly- -olefins, polyamide, polyester, and cellulose. Special attention has been paid to morphological properties because they have a significant effect on mechanical and thermal properties.Throughout this study, the morphology and the mechanical properties of semicrystalline polymers were clarified. More precisely, (1) The crystal lattice moduli in the chain direction for polyethylene (PE) and polypropylene (PP) are independent of temperature close to their melting Points, but their Young's moduli decreases with temperature. This is due to a decrease in their crystallinity with temperature. (2) The crystal lattice modulus and the linear thermal expansion coefficient measured by X-ray diffraction are different from the intrinsic crystal lattice modulus and the coefficient in a general polymeric system, in which the oriented crystalline layers are surrounded by an oriented amorphous phase. (3) The origin of the crystal dispersion of PE and PP are dependent upon their own morphology. Namely, the activation energies of the crystal dispersion become lower with increasing draw ratio. (4) The cross-linking of PE is performed with a chemical reaction using dicuml peroxide under drawing process of the dried gel film. The drastic improvement in high temperature resistance is realized for the specimens with Young's modulus of 100 GPa at 20ﾟC.