Studies on the Structures and Properties of Latent - crimp Copolyestcr Fibers

The internal causes of latent-crimp were analyzed bystudying the supermolecular structures of the standardpolyester fibers(PET),copolyester fibers(IPET)andtheir side-by-side composite fibers(PET/IPET)inthis paper.It is concluded that IPET and PET/IPEThave better latent-crimp ability because of their asym-metric supermolecular structures.At the same time,they have good dyeability and mechanical properties.Soit is a simple and low cost process to manufacture latent-crimp continuous fibers by melt-spinning of the co-polyester IPET.     

Crystallization Behavior of Copolymer Poly(ethylene terephth-alate/isophthalate)(IPET)

The non-isothermal crystallization kinetics, isothermal crystallization and the morphology of crystals of the copolymer poly ( ethylene terephthalate/ isophthalate ) (IPET) were studied by DSC and polarized-light microscopy in this paper. DSC results indicate that the glass transition temperature Tg of IPET is slightly lower than that of poly (ethylene terephthalate) (PET), but the melting temperature Tm and the crystallization temperature Tc of PET and IPET have much difference. The difference of Tc between PET and IPET2 is about 7℃, and the difference of Tm between PET and IPET2 is about 16℃. From the kinetics analysis of the crystallization, the crystallization mechanism of all samples is of three-dimension spherulitic growth from instantaneous nuclei and the incorporation of isophthalate (IPA) decreases the crystallization rate of IPET greatly. The isothermal results indicate that the morphologies of PET and IPET crystals are all spherulite, which is in conformity to the results of non-isothermal d     

The Surface Properties and Tensile Strength of HSPE Fiber Treated by Controlling Oxidation in Chromic Acid

This work reported on the surface modification of high strength polyethylene(HSPE)fiber by chemical etching in chromic acid.The surface chemistry,the functional group contents, the wetting ability, the surface morphology and the tensile strength of modified fibers were investigated. The results show that, the surface roughness,surface wet properties and active functional group can be introduced on the HSPE fiber surface by this method,which will improve the interface adhesion in the composites, and the decrease of the tensile strength of modified fibers can be controlled.     

共聚酯的非等温结晶动力学研究

应用差示扫描量热法(DSC),研究了含有间苯二甲酸乙二酯(EI)的共聚酯(PEIT)的非等温结晶动力学,得到了不同间苯含量(A_1相似文献   

残留溶剂对连续莫来石纤维干法纺丝的影响

以干法纺丝制备连续莫来石纤维,研究残留溶剂质量分数在纺程上的变化以及甬道温度、纤维直径对其影响.实验结果显示:沿平行纺丝线方向,残留溶剂质量分数的变化分为3个阶段,变化最快的阶段在距离喷丝板1m长度范围内,残留溶剂质量分数变化量占全程变化总量的60%～63%;沿垂直纺丝线方向,溶剂蒸发分为2个阶段,通过计算机模拟得到了残留溶剂在纤维横截面上的分布曲线.相同实验条件下,纺丝甬道温度升高30℃,残留溶剂质量分数降低2%～3%;纤维直径增大30μm,残留溶剂质量分数减少1%～2%.在实验范围内,最佳纺丝甬道温度为80℃,最佳纤维直径为80～90μm.     

Kevlar纤维的结构、性能及其应用

本文概述了 Kevlar 纤维的大分子结构、超分子结构及其物理、化学、机械性能(力学、耐热、耐光、耐辐射、溶解性、吸湿性等等),并介绍了 Kevlar 纤维在帘子线、编织物、复合材料等方面的应用。     

纤维素在氢氧化钠/硫脲/尿素/水溶液中的溶解和溶液特性

使用氢氧化钠/硫脲/尿素/水溶液作为纤维素的复合溶剂,研究了纤维素在其中的溶解行为和溶液性质,发现该体系在-10℃条件下能快速溶解纤维素,其溶解是一个没有衍生物生成的直接过程,该纤维素溶液在过高温度下易凝胶化.     

Solubility Behaviour of Cellulose in a Sodium Hydrate/Urea/Thiourea Aqueous Solvent

Cellulose pulps were directly dissolved in a green solvent of sodium hydrate/urea/thiourea/water with different composition for the purpose to prepare new regenerated cellulose fibers or films. The results showed that the highest solubility of cellulose in the solvent with the composition of 8/8/6.5/77.5. The results revealed that the pulp feeding sequence, stirring rate, pre-treatment of pulp and pulp size affected the cellulose concentration in the green solvent. Accordingly, the more effective dissolution method was proposed in order to get higher concentration of cellulose. Furthermore, the properties of solution prepared by different kinds of pulps in the solvent were investigated by ARES rheometer. Rheologieal analyses indicated that all cellulose aqueous solutions in their high concentration were pseudoplastic fluids and sensitive to temperature and tended to transform to gel when temperature increased.     

Acetalization of Poly（vinyl alcohol） /Soybean Protein Fibers

Acetalizatioin on the blend fibers of poly （vinyl alcohol） （PVA） and soybean protein （SP） was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square experiment, where the modified fibers with good mechanical properties can be achieved by treating in 41 g/L dialdehyde solution at 67 ℃ for 9 min. The cross-linking reactions of PVA and SP with dialdehydes were confirmed by Fourier transform infrared （FTIR） spectroscopy. Tensile test and boiling water shrinkage measurements showed that the physical properties of PVA/SP fibers crosslinked by dialdehydes were improved comparing with those formalized fibers.     

Ce(IV)/PEO-NH2氧化还原引发体系制备聚丙烯腈-聚环氧乙烷嵌段共聚物的研究

首先利用阴离子聚合，合成了含有胺端基的大分子引发剂聚环氧乙烷（PEO－NH2），然后利用铈离子与聚环氧乙烷组成氧化还原引发体系，在水溶液中合成了聚丙烯腈与聚环氧乙烷的嵌段共聚物（PAN－b-PEO)，通过FT－IR，NMR，GPC等分析测试确定了嵌段共聚物的生成，并对反应条件对聚合的影响进行了分析研究。结果表明，产率随着温度的升高而呈增加趋势；随着经发剂PEO－NH2含量的增加，产率开始呈增加，然后呈下降趋势。