Preparation of ferromagnetic binary alloy fine fibers by organic gel-thermal reduction process

Ferromagnetic metal fibers with a high aspect ratio （length/diameter） are attractive for use as high performance electromagnetic interference shielding materials. Ferromagnetic binary alloy fine fibers of iron-nickel, iron-cobalt and cobalt-nickel were prepared by the organic gel-thermal reduction process from the raw materials of critic acid and metal salts. These alloy fibers synthesized were featured with a diameter of about 1 pm and a length as long as 1 m. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of the gel precursors were characterized by FTIR, XRD, TG/DSC and SEM. The gel spinnability largely depends on the molecular structure of metal- carboxylates formed during the gel formation. The gel consisting of linear-type structural molecules shows good spinnability.     

PVA伴纺牦牛绒产品退维实验探讨

牦牛绒纤维可纺性能差,纯纺难度大,通过PVA纤维伴纺牦牛绒既可提高牦牛绒纤维的可纺性和可织造性,又能获得高支轻薄的高档纯牦牛绒纺织品。文章以水溶性PVA纤维与碘能发生特殊的显色反应为理论依据,对PVA纤维伴纺牦牛绒纱线和针织物的退维机理和影响因素进行了实验和探讨。从结果来看,溶胀溶解时间和温度对水溶性PVA纤维溶解有较大影响;水溶性PVA纤维的状态不同(如纱线和织物),其溶解性能有一定的差异;要彻底去除PVA纤维,浴比要大些,以采用两浴两步法或三浴三步法退维工艺为好。     

Electrospinning of Technical Lignins for the Production of Fibrous Networks

Abstract

Electrospinning is an effective strategy to produce micron and sub-micron diameter fibrous networks from a variety of polymeric systems. Using seven different technical lignins the effect of lignin structure on fiber formation by electrospinning was studied. Surprisingly, none of the technical lignins could be electrospun into continuous fibers, although beaded fiber formation was observed for the softwood Kraft lignin system at high concentration (>50 wt%). However, the addition of poly(ethylene oxide) dramatically affected the electrospinning behavior and fiber formation. For all of the technical lignins a clear transition from electrospray or beaded fibers to uniform fibers was observed upon addition of poly(ethylene oxide); the lignin concentration dependent on poly(ethylene oxide) content. In all of the systems a linear increase in fiber diameter with increasing lignin concentration was observed. At the same concentration, the various lignin solutions had varying viscosities and different electrospinning behavior, that is, fiber diameter and ability to form uniform fibers, suggesting lignin specific structures and intermolecular interactions are influencing solution properties and electrospinning behavior. In fact, specific viscosity versus concentration plots reveal scaling exponents’, η ～ c^7.4–7.8 consistent with a branched polymer participating in intermolecular interactions such as hydrogen bonding or association complexes.     

高密度壳聚糖溶液流变性能及可纺性研究

以乙酸为溶剂,配置了高密度壳聚糖(HDC)纺丝浆液;以氢氧化钠/乙醇溶液为凝固浴,采用湿法纺丝制备HDC中空纤维;研究了纺丝浆液的流变性能及可纺性,并对HDC-中空纤维的结构与性能进行表征。结果表明:在HDC质量分数为2%～6%,温度20～70℃条件下,HDC纺丝浆液属于剪切变稀的假塑性流体,非牛顿指数小于1.0;HDC质量分数为5%的纺丝浆液在20～30℃下,以质量分数3%的氢氧化钠/乙醇(质量比1/1)作为凝固浴进行湿法纺丝,可纺性良好,得到的HDC中空纤维结构较完善,力学性能较好,纤维线密度为0.27 dtex,断裂强度为0.72 cN/dtex,断裂伸长率为6.09%,模量为6.12 GPa。     

冰凉纤维／牛奶纤维／棉混纺针织纱的开发

文章介绍了冰凉纤维、牛奶纤维的性能,探讨了冰凉纤维／牛奶纤维／棉混纺针织纱混纺性能以及纺部的生产技术要点。生产的产品质量达到预期效果。     

The effect of melt spinning process parameters on the spinnability of polyetheretherketone

This study has been carried out to investigate the processing parameters affecting polyetheretherketone's (PEEK) spinnability in a melt spinning process. PEEK has excellent mechanical and thermal properties and fibers made from it could be used in extreme environments. Different PEEK grades were characterized thermally and rheologically to see which one is the most suitable for fiber spinning. The spinning tests made with the most suitable grade (Victrex 151G) show that increased processing temperature, increased capillary diameter or shorter spinning path length improves spinnability. The best fibers made in optimal processing conditions (400°C temperature, 30/1 mm capillary, and 5 cm spinning path) were 18 μm in average diameter. Because of the limitations of the system used, variations in fiber thickness were noticeable and worsened the spinning stability. Scanning electron microscope photos confirmed these variations, and they were also visible in an optical microscope. The selected low‐viscosity PEEK grade provided good spinnability but gave filaments with only mediocre mechanical properties, the tensile strength being around 280 MPa. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

生物质桑皮纤维的绿色高效产业化开发途径

结合桑枝的特点,设计开发了桑枝剥皮机进行快速剥皮,采用循环脱胶装置对桑皮进行脱胶提取桑皮纤维和果胶,研究纤维的可纺性能,开发桑皮纤维纱线及其功能纺织品;利用成膜装置对不完全脱胶的桑皮纤维进行成膜开发非织造产品,提升产品的附加值,具有非常广阔的产业化和市场前景。     

不锈钢纤维及其功能性纺织品的研究现状与展望

结合不锈钢纤维的概念、功能与用途，介绍了不锈钢纤维的性能特点、制取方法，同时介绍了不锈钢纤维的纺织加工技术、方法与工艺措施以及不锈钢纤维功能性纺织品研究开发的现状与发展趋势。     

聚乙二醇改性热塑性环氧树脂及其可纺性

为拓宽热塑性环氧树脂在纺织材料领域的应用,以聚合-热压工艺制备了热塑性环氧树脂膜,进一步利用熔融分散工艺将聚乙二醇(PEG)分散至热塑性环氧树脂中制备环氧树脂/PEG粒料,并通过熔融-牵伸工艺制备环氧树脂/PEG长丝。探讨了环氧树脂/PEG的可纺性,分析了环氧树脂膜和环氧树脂/PEG长丝的力学与动态力学性能。结果表明：所制备的环氧树脂膜屈服应力为64.6 MPa,玻璃化转变温度可达100.2℃;PEG的加入使环氧树脂/PEG粒料的挤出力显著降低,当PEG质量分数为5%时,相比于纯环氧树脂挤出力降低了870 N;PEG对热塑性环氧树脂的纺丝温度具有调控作用,当PEG质量分数为7.5%时,相比于纯环氧树脂粒料,环氧树脂/PEG粒料的纺丝温度降低了30℃;经PEG改性后的环氧树脂长丝具有更小的直径和更优异的力学性能,相比于纯环氧树脂长丝,PEG质量分数为7.5%的环氧树脂/PEG长丝直径降低了50μm, PEG质量分数为2.5%的环氧树脂/PEG长丝的断裂应变与断裂应力分别增加了60%和20 MPa。     

大麻杆浆粕制造黏胶短纤维工艺初探

从利用大麻杆开发黏胶纤维的目的出发,探索了用大麻杆浆粕经浸渍、磺化及纺丝工艺制黏胶纤维的方法,对浸渍时间、磺化时间等工艺条件进行了摸索. 结果表明:浸渍时间大于60min时可以去除大麻杆浆粕中大量的半纤,磺化反应的最佳时间为100min;上述条件下制得的溶解胶可纺性能较好,纺丝过程顺利,纺制出的黏胶短纤维基本力学性能良好,证实了大麻杆浆粕作为黏胶短纤维原料的工艺可行性.