Morphology and Thermal Behavior of Polypropylene/Easily Hydrodegraded Polyester Blend Fibers

Ultrafine polypropylene fibers are prepared frompolypropylene/easily hydro - degraded polyester （PP/EHDPET） blend fibers, in which file EHDPET compo-nent is degradable by treating with NaOH - H2O solu-tion. We investigated the morphology of PP/EHDPETblend fibers before and after stretching and alkalinehydrolysis. Then thermal behavior of the blend has alsobeen studied.

Alkaline Hydrolysis of PP/EHDPET Blend Fibers

Polypropylene superfine fibers or cell porous fibers were prepared from the bi-component blend fibers of polypropylene/easlly hydro-degraded polyester(PP/EHDPET)by alkaline hydrolysis process. EHDPET is a kind of copolyester that can be rapidly hydro-degraded in the hot alkaline solution. This paper discussed the kinetics of alkaline hydrolysis of EHDPET, and the effect of catalyst, bulk ratio and the content of polypropylene grafted maleic anhydride (PP-g-MAH) on the alkaline hydrolysis process. Meanwhile, the morphological change of the outer surface of blend fibers during this process was also investigated by the technology of scanning electron microscope (SEM).

KINETICS AND MECHANISM RELATING ALKALINE HYDROLYSIS OF POLYESTER BLEND FIBER

Cation Dyeable Polyester(CDP)was made by copolymerizing dimethyl terephthalate(DMT),S-sodium sulfonate dimethyl isophthalate(SIPM) with a weight fraction of 4.5% and ethyleneglycol (EG).Blend of PET and CDP was spun into hollow fiber.The fiber was then treated withaqueous NaOH.In this paper,kinetics and mechanism of alkaline hydrolysis of PET,CDP andtheir blend PET/CDP fiber were studied by means of specific area measurement,scantling elec-tron microscopy and other chemical analyses.It was showed that the rate of alkaline hydrolysis isCDP】PET/CDP】PET.Because of blending effect,the alkaline hydrolysis of PET/CDP is dif-ferent from that of PET.CDP phase in the PET/CDP fiber is predominantly hydrolyzed,andhence some pieces of fiber(micro-fiber) fall off the fiber because of etching.

Preparation and Properties of Regenerated Cellulose/Amylopectin Blend Fibers from 1-Butyl-3-Methylimidazolium Chloride with Controlled Biodegradation

Regenerated cellulose/amylopectin blend fibers with controlled biodegradation were produced using dry-jet wet-spinning technology from cellulose/amylopectin/1-butyl-3-methylimidazolium chloride blends.Morphological,structural and chemical analyses revealed that dense,homogeneous and void-free blend fibers were prepared in a two-stage dissolution process.The blend fibers were regenerated from water and treated with water or 95%(volume fraction)ethanol.However,cellulose-amylopectin interactions caused crystalline rearrangements in the blend fibers,resulting in a general decrease in crystallinity.Generally,tensile properties decreased with increasing amylopectin content,except that the blend fibers with 10%(mass fraction)amylopectin exhibited higher tensile strength than the regenerated cellulose control fibers.Ethanol treatment reduced the hydrophilicity of the blend fibers,increasing the crystallinity of the blend fibers.The blend fibers exhibited remarkable degradation,directly proportional to the amylopectin content.Despite higher crystallinity,ethanol-treated blend fibers degraded faster than water-treated fibers,indicating amylopectin and ethanol regulated the degradation.

Changes in Structure and Properties of Soybean Protein/Poly(vinyl alcohol) Blended Fibers Subjected to Wet Heat Treatment

The properties of soybean protein/poly（vinyl alcohol） （SP/ PVA） blended fibers subjected to wet heat treatment in hot water were measured. The structure of fibers was investigated by scanning electron microscope （SEM）, Fourier transform infrared （FTIR） spectroscopy, wide-angle X-ray diffraction （WXD） and differential scanning calorimetry （DSC）. The results show that the wet heat treatment above 100℃ has a great influence on the properties and structure of SP/PVA blended fibers. After the wet heat treatment at high temperature, the fibers exhibit the severe shrinking and yellowing, the great decrease in breaking strength and adhesive aggregation. The fibers show a broader main X-ray diffraction peak with the disappearance of minor diffraction peaks, a double DSC melting behavior with the peak temperatures of 215 and 233℃, and a weaker intensity of crystallization-sensitive absorbance peak of PVA component at 1 142 cm^-1. Therefore it is concluded that the wet heat treatment above 100℃ leads to a change in the crystalline structure of fibers and the scission and degradation of PVA macromolecular chains.

Color Matching of Pre-colored Fiber Blends Based on Two-Constant Kubelka-Munk Theory

Some modifications of two-constant Kubelka-Munk theory has been made for the color matching of pre-colored fiber blends. The scattering coefficients of three primaries are averaged and taken as initial coefficients in each wavelength. The unit sums of concentration in E-Allen’s Algorithm were removed in the case of pre-colored fiber blends. Predicted blend ratios and reflectance curves agree very well with measured ones and color differences are within the tolerant limit, showing satisfactory matching results.

Optimization of the Processing conditions of SA-CS blending fiber by RSM

Based on results of single factor experiments,analytical levels for three additives were established and experimental scheme was designed by central composite of response surface methodology(RSM) with the software of Design-Expert 7.1.6.Funnily,we got the SA-CS blending fiber with a strength of 13.56 cN/tex,should be spun at the conditiongs as follows: The mass dosage of SA to the polysaccharide was 48.89%,the temperature of the water bath was 58.57℃,and the response time was 29.31 minutes.,and in the predict model,the result shows as 13.5688cN/tex,compared the later with the former,it has the error of 0.064%.

Blended Yarns of Modacrylic Fibers with Silk Protein

The fiber properties of modacrylic fibers with silk protein and spinning technology for blended knitting yarns are studied. By testing the fiber properties, fiber spinnability is analysed. Modacrylic fibers with silk protein are brittle and have poor cohesion, so the key to process modacrylic fibers with silk protein lies in forming lap and sliver. During opening and carding, low speed is used to decrease fiber damage and the proper static resistant oil is applied to eliminate lapping fibers. Besides, the temperature and relative humidity have to be strictly controlled. The applications of modacrylic fibers with silk protein are also put forward.

The Strength of PLA Fiber/Tencel Blended Yarn

The PLA fiber is one of the green fibers.It is blended with Tencel fibers.The strength of the PLA fiber/Tencel blended yarn is tested.The relationship between the strength and the twist factor and the blended ratio is analyzed.The optimum blended ratio of the blended yarn is determined.

ESTIMATION OF BLENDING RATIO OF TWO-COMPONENT FIBER BUNDLE FROM BUNDLE LOAD-ELONGATION CURVE

In this paper, two methods were developed to assess the blending ratio of two-componentfiber bundles. They were the peak-height method and the slope method. The relationship be-tween blending ratio and testing data was analysed, and the regression curves were obtained bystepwise regression method. It was pointed out that the testing errors of both methods were lessthan two percent. The validities of both methods were verified by experiments, All calculationsof both methods were completed by computer. The blending ratio was ascertained from the test-ing data of bundle fiber strength tester which was made by the authors themselves.

Blending Ratio Analysis of Akund / Cotton Blended Yarn Based on Micro Projection

A microscope method was developed for testing the blending ratio of akund/cotton blended yarns. Fiber characteristics such as diameter, longitudinal feature, and hollow structure were observed to identify akund and cotton. Therefore, the measurement of the blending ratio for akund/cotton blended yarns based on each fiber's amount, moisture regain, and metric count was available. The results show that using specimen's longitudinal section is more effective during the fiber counting than specimen's transverse section benefiting from the separation of the fibers.

钢-植物纤维混掺增强混凝土力学性能研究

在混凝土中加入外掺纤维材料可以有效改善混凝土的力学性能,几种外掺纤维通过一定的比例混掺增强混凝土的力学性能相比单一纤维单掺入有更好的增强效果。植物纤维广泛存在于自然界,且有产量大、易获取、环保且可再生等优点。选取竹纤维、剑麻和黄麻3种植物纤维与钢纤维混掺,通过试验分析钢-植物纤维混掺对混凝土劈裂抗拉、抗剪以及抗冲击性能的增强效果,并与单掺钢纤维进行对比分析,验证了钢-植物纤维增强混凝土力学性能的可靠性。同时通过对3种植物纤维与钢纤维混掺的掺入量和配合比进行影响分析,提出了钢-植物纤维混掺增强混凝土的优化方案,并提出响应掺入量、配合比的建议值,为试验研究和工程应用提供借鉴和参考。

Study on the Properties of Newdal Blended Knitted Fabrics

The basic properties of the 3 knitted fabrics are measured with different instruments.Testing standards are tensile,break drape,wear resistance,pilling property and bending properties.By the analysis of the results,the following conclusions can be deduced: Among the 3 fabrics,the mechanical properties of the blended knitted fabrics Newdal /Polyester is the best.

Fabrication of polymer/fluoride-containing salts blend composite membranes for CO_2 separation

Poly （N,N-dimethylaminoethyl methacrylate）-poly （ethylene glycol methyl ether methacrylate） （PDMAEMA-PEGMEMA） and cesium fluoride （CsF） were blended and used as the separation material of composite membranes.Hollow fiber composite membranes were fabricated by coating the blend on polysulfone （PSf） hollow fiber substrate.Introduction of fluorine ion improved the separation performance of the membrane.The concentration of coating solution was adjusted to obtain a membrane with high permeance.The composite membrane showed good performance with the CO2 permeance of 30.4 GPU （1 GPU=10-6 cm3 （STP）/（cm 2 s cmHg））,and selectivities to CO2/N2,CO2/CH4,CO2/H2 and O2/N2 of 47.2,37.6,1.75 and 4.70,respectively.Potassium fluoride （KF）,due to its low cost,was also used as a substitute of CsF to prepare composite membrane and the permeation data showed that CsF can be replaced by KF.The effect of operating temperature on the permeation properties of the composite membrane was also investigated.

生物基功能环保纱线的开发与应用现状

为深入探究生物基功能环保纱线的工艺措施,通过查阅大量有关文献进行归纳总结,得出不同类别生物基纤维的预处理、加工过程工艺参数设定、纺纱环境及工艺原则等。指出:对于强力比较低的生物基纤维需要进行自由开松,以避免损伤纤维;对于回潮率较高的生物基纤维,需控制好车间温湿度,使纤维最好处于放湿状态,以防止纤维缠绕胶辊;对于可纺性能比较差的生物基纤维,为不影响成纱强度,其占比不超过30%;对于易产生静电的生物基纤维,为提高其蓬松性,需对纤维喷洒预处理剂,且密封处理24 h以上;对于长度较长的生物基纤维,为减小纤维损伤,开清棉采用“以梳代打,减少落棉,降低打手速度”的原则,梳棉工序采取“低速度,大隔距,适当增加锡林刺辊线速比”的原则,实现纤维快速转移。

不同尺寸石墨烯增强PA66纤维的效果分析

为提高PA66的力学性能,以石墨烯(GN)为基础填料,十二烷基苯磺酸钠(SDBS)作为表面活性剂,将GN均匀分散在SDBS的水溶液中,利用超声波粉碎技术,分别获得大尺寸(LGN)、中尺寸(MGN)、小尺寸(SGN)的GN,然后用熔融共混法制备出不同尺寸以及不同添加量的GN改性PA66,并对其性能进行了表征。研究结果表明:对于添加不同尺寸的GN,质量分数0.1%的SGN加入时,改性纤维的断裂强度提高至6.34 cN/dtex,较纯PA66提高了12.8%。同时SGN改性PA66的相对结晶度提升最大,为40.2%,相较于纯PA66提高了19.6%;对于不同添加量的SGN,SGN质量分数为0.1%时,改性纤维的断裂强度达到最大,力学性能提升最大。SGN的加入有利于异相成核,结晶速度相对加快。SGN改性PA66的最大分解速率温度为421.7℃,较纯PA66提高了9℃左右,说明SGN与PA66基体间发生了界面相互作用,具有热失重的延缓效果,加入SGN后PA66不易发生热分解。认为:添加一定量SGN能够更好提升PA66的各项性能。

植物纤维增强混凝土力学性能试验研究

以剑麻纤维、黄麻纤维和竹纤维为增强体,研究了植物纤维对混凝土的抗压、抗折等力学性能的增强效果,以及植物纤维的长度、掺入量和纤维分布对增强效果的影响,并与聚丙烯纤维增强效果进行对比分析。试验证明:植物纤维对混凝土抗压强度的影响可忽略不计,但对混凝土抗折强度产生重要影响。剑麻纤维(长度20 mm,体积分数1.5%)、竹纤维(长度10 mm,体积分数1.0%)和黄麻纤维(长度10 mm,体积分数1.5%)增强效果均较好,竹纤维增强效果优于其他两种植物纤维。植物纤维混掺增强效果优于单一植物纤维增强效果,总体积分数1.5%的“剑麻纤维—黄麻纤维—竹纤维”混掺增强效果最好。

PP/玻纤/EPDM-g-MAH复合材料性能研究

采用挤出熔融共混方法制备了马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)。研究了玻纤用量、EPDM-g-MAH用量对PP力学性能、热变形温度的影响。研究结果显示:在玻纤用量5~30份的区间内,随着玻纤用量的增加,PP/玻纤复合材料的冲击强度、拉伸强度、弯曲强度均逐渐增大,在玻纤用量30份时,缺口冲击强度为10.29 kJ/m^(2),约为纯PP的4.38倍,热变形温度呈上升趋势。而在EPDM-g-MAH用量为5~30份的范围内,随着EPDM-g-MAH添加量的增加,PP/玻纤/EPDM-g-MAH复合材料的缺口冲击强度先是上升,而后下降。在EPDM-g-MAH用量15份时,冲击强度最高,达到了13.38 kJ/m^(2),约是纯PP的5.69倍,热变形温度则呈下降趋势。

阻燃纤维/不锈钢纤维混纺纱线的力学性能分析

为探讨混纺比对纱线性能的影响,测试分析了5种不同混纺比的阻燃腈纶(A)/阻燃黏胶(R)/不锈钢纤维(G)(A90/G10、A70/R20/G10、A45/R45/G10、A20/R70/G10、R90/G10)混纺纱线的力学性能。结果表明:混纺纱线的拉伸断裂性能、弹性、蠕变性能、耐磨性能、扭转性能和弯曲性能随阻燃腈纶纤维混纺比的增加而提升;A45/R45/G10混纺纱线的疲劳性能较差,A90/G10混纺纱线的疲劳性能较好;在较大压力下,A70/R20/G10和R90/G10混纺纱线的压缩性能较好,在较小压力下,A20/R70/G10混纺纱线的压缩性能较好。

精梳工艺对混色纱纤维径向混和效果的影响

为探讨精梳工艺对涤粘混色纱纤维径向混和效果的影响,基于纤维成像法观察混纺纱横截面的纤维分布情况,建立了混纺纱横截面纤维径向混和不匀率的数学模型,采用涤粘普梳混纺工艺路线与涤粘精梳混纺工艺路线分别制备两种混纺比的涤粘混色纱,计算两种混色纱的纤维径向混和不匀率。结果表明:涤粘精梳混纺工艺能够显著提高纱线截面内的纤维径向混和均匀性;与涤粘普梳纱相比,涤/粘混纺比为65/35时,涤粘精梳混纺纱的涤纶径向混和不匀率降幅为42.88%,粘胶纤维径向混和不匀率降幅为41.91%;涤/粘混纺比为50/50时,涤粘精梳混纺纱的涤纶、粘胶纤维径向混和不匀率降幅分别为40.57%、39.55%;涤粘普梳混纺工艺对纤维混纺比的控制更加准确。