Extraction and characterization of natural cellulose fibers from common milkweed stems

Natural cellulose fibers with cellulose content, strength, and elongation higher than that of milkweed floss and between that of cotton and linen have been obtained from the stems of common milkweed plants. Although milkweed floss is a unique natural cellulose fiber with low density, the short length and low elongation make milkweed floss unsuitable as a textile fiber. The possibility of using the stems of milkweed plant as a source for natural cellulose fibers was explored in this research. Natural cellulose fibers extracted from milkweed stems have been characterized for their composition, structure, and properties. Fibers obtained from milkweed stems have about 75% cellulose, higher than the cellulose in milkweed floss but lower than that in cotton and linen. Milkweed stem fibers have low % crystallinity when compared with cotton and linen but the strength of the fibers is similar to cotton and elongation is higher than that of linen fibers. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

芳香族聚噁二唑纤维的制备及其结构与性能

简要介绍了芳香族聚噁二唑纤维的研究背景。以发烟硫酸为溶剂和脱水剂,对苯二甲酸和硫酸肼为单体,合成了聚对苯撑-1,3,4-噁二唑,通过溶液纺丝制备了耐高温纤维,并对纤维的结构、热性能、阻燃性、染色性等做了初步研究。结果表明:芳香族聚噁二唑纤维具有优异的耐高温、阻燃、电绝缘性能,以及良好的纺织加工性能和可染性,具有广阔的应用前景。     

Flame retardant polyesters. III. Fibers

Most of the commercial flame retardant (FR) polyester fibers are produced using copolymerization with phosphorous FRs. We investigated the fiber properties, dyeing properties, and flame retardancy according to the phosphorous FR type. The physical properties of both the fibers are similar and suitable for textile application. But the dye adsorption rate is much faster in the case of main chain type. This is resulted from higher chain mobility analyzed by glass transition temperature. The main chain type FR polyester fiber adsorbed the dyestuff at lower temperature and reached exhaustion more quickly. And the resistance to chemicals such as acidic and alkaline solutions at high temperature have similar tendency with dye absorption. The migration of dyestuffs and chemicals into the polymer chain has good correlation with chain mobility of the polymers. The main chain type polyester fiber shows better flame retardancy than pendant type polyester, which might be brought about from more rapid degradation into polyphosphoric acid. The main chain type polyester fiber shows better flame retardancy than pendant type polyester. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

莲纤维的形态研究

莲纤维是从农业废弃物荷秆中提取的纤维,是一种环保型天然纤维。通过生物显微镜及扫描电子显微镜观察,研究了莲纤维的基本形态特征。结果表明,经物理方法提取的莲纤维细长柔软,纵向有横节,外观乳黄。扫描电镜观测发现,单根莲纤维是由数根直径约4μm的微细纤维横向缔合而成,间距3～5μm。纵向呈带状螺旋转曲,横截面有中腔和孔洞。     

Softness evaluation of keratin fibers based on single‐fiber bending test

The evaluation of single‐fiber softness by bending is an ingenious and vital approach for the basic investigation of both the fiber bending properties and the textile softness. The bending behavior and bending modulus of wool, alpaca and silk fibers have been measured by an axial‐buckling method developed by the authors, which uses the fiber compression bending analyzer (FICBA). The bending properties of single fibers were quantified by calculating the equivalent bending modulus and the flexural rigidity by measuring the protruding length and diameter of fiber needles and the critical force, P_cr, obtained from the peak point of the force‐displacement curve. The measured data showed that the equivalent bending modulus of the alpaca fiber is higher than that of wool fiber, and even the rigidity is 10 times as high as wool, but its friction coefficient is lower than that of wool, which means that the soft handle of alpaca fabrics is mainly due to the smooth surface and low friction coefficient of alpaca fibers in contrast to that of wool fiber. For the silk fiber, despite high equivalent bending modulus, the smoother handle of silk should be mainly due to the thin fiber diameter in contrast to that of keratin fibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 701–707, 2006     

两种功能性纤维素纤维的性能研究

对两种功能性纤维素纤维——阻燃纤维素纤维、珍珠纤维素纤维与普通黏胶纤维的形态结构、吸湿性能、电学性能、摩擦性能及力学性能进行了对比,试验表明:阻燃纤维素纤维和珍珠纤维素纤维的横向、纵向形态结构与普通黏胶纤维相似,其吸湿、放湿性能优良,断裂强度及断裂伸长率比普通黏胶有所降低。两种功能性纤维有良好的可纺性,可以借鉴普通黏胶的纺纱工艺加工纯纺或混纺纱线,开发具有一定保健功能的纺织品,织物服用性能好,是优良的纺织原料。     

An improved method for single fiber tensile test of natural fibers

An improved Single Fiber Tensile Test (SFTT) for the natural fibers was depicted. Natural fibers have irregular shape, and are not uniform along the fiber length and also from one fiber to another. Applying the conventional method, which determine the fiber cross‐section by measuring the fiber diameter using optical microscopy, will result in inaccurate properties of the natural fibers with large standard deviation (SD). In the proposed new SFTT method, an accurate cross‐section area could be obtained from the Scanning Electron Microscope observation of a flat and clear fractured end surface of carefully selected tensile‐tested fibers and calculated using imaging analysis. Applying this new approach, tensile strength of different types of flax fiber, including bast fiber, enzyme‐retted and water‐retted fiber provided SD of less than 11%, while those of these fibers determined by the conventional approach had SD of over 24%. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Injection‐molded short hemp fiber/glass fiber‐reinforced polypropylene hybrid composites—Mechanical,water absorption and thermal properties

Natural fiber‐based thermoplastic composites are generally lower in strength performance compared to thermoset composites. However, they have the advantage of design flexibility and recycling possibilities. Hybridization with small amounts of synthetic fibers makes these natural fiber composites more suitable for technical applications such as automotive interior parts. Hemp fiber is one of the important lignocellulosic bast fiber and has been used as reinforcement for industrial applications. This study focused on the performance of injection‐molded short hemp fiber and hemp/glass fiber hybrid polypropylene composites. Results showed that hybridization with glass fiber enhanced the performance properties. A value of 101 MPa for flexural strength and 5.5 GPa for the flexural modulus is achieved from a hybrid composite containing 25 wt % of hemp and 15 wt % of glass. Notched Izod impact strength of the hybrid composites exhibited great enhancement (34%). Analysis of fiber length distribution in the composite and fracture surface was performed to study the fiber breakage and fracture mechanism. Thermal properties and resistance to water absorption properties of the hemp fiber composites were improved by hybridization with glass fibers. Overall studies indicated that the short hemp/glass fiber hybrid polypropylene composites are promising candidates for structural applications where high stiffness and thermal resistance is required. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2432–2441, 2007     

绿色纺织纤维的性能与应用

介绍了几种典型的绿色纺织纤维,如彩棉、竹原纤维、大麻纤维、Lyocell纤维、甲壳素纤维的性能与应用,并对绿色纺织纤维的发展趋势进行了预测。     

锦葵纤维增强聚丙烯基复合材料力学性能研究

分别制备了锦葵纤维含量为10 %（质量分数,下同）、20 %、30 %、40 %和50 %的锦葵纤维增强增强聚丙烯基复合材料,研究了纤维含量对该复合材料拉伸性能和弯曲性能的影响,并与苎麻纤维增强聚丙烯基复合材料进行了对比。结果表明,随着锦葵纤维含量的增加,锦葵纤维增强聚丙烯基复合材料的拉伸强度和拉伸弹性模量逐渐增加,而弯曲强度和弯曲弹性模量呈现先增大后减小的趋势,当纤维含量为40 %时达最大值;纤维含量均为30 %时,除拉伸弹性模量外,锦葵纤维增强聚丙烯基复合材料的各项指标均低于苎麻纤维增强聚丙烯基复合材料。     

玉米苞叶纤维的形态结构

为开发利用废弃玉米苞叶作为纺织纤维原料,用Na OH溶液对玉米苞叶进行处理制得了玉米苞叶纤维;通过观察制得的玉米苞叶纤维形态确定了最优的Na OH溶液制取的方法,实验室最佳制取方法为15%Na OH溶液、温度80℃、处理时间2.5 h;用傅里叶红外光谱仪获得玉米苞叶及其纤维的红外光谱图,表明玉米苞叶纤维主体成分为纤维素;用CU-6纤维细度分析仪观察玉米苞叶纤维的表面形态结构,发现其纵向类似棉纤维天然转曲,横截面有不规则中空形态。     

无机特种纤维介绍(一)

无机特种纤维具有优异的力学性能和耐高温、抗氧化的热学性能,在高科技领域应用越来越广泛。对无机特种纤维中的玻璃纤维、玄武岩纤维、碳纤维的结构与性能、发展情况、制备方法以及主要应用领域进行了简要介绍,最后简要总结了这3种纤维的发展过程,展望了其发展前景及发展方向。     

Melt spinnability of long chain cellulose esters

Technical and hygienic nonwovens, originating typically from fossil-based synthetic polymers, are the fastest growing applications in the textile industry. Recently developed thermoplastic cellulose fatty acid esters have polyolefin like rheology properties and therefore the suitability of these cellulose esters for fiber production was evaluated. In this study, the melt spinning of textile fibers has been demonstrated using thermoplastic cellulose octanoate. The mechanical properties of melt spun fibers were analyzed by using tensile testing and both the surface and cross-section morphology of melt spun fibers were studied using the scanning electron microscopy. The surfaces of the fibers were very smooth and also the cross-section was very uniform and no porosity was observed. While mechanical properties of the produced fibers are not yet as good as those reported for commercial polypropylene (PP) monofilament fibers, they are somewhat more comparable to other cellulose ester-based fibers. The melt spinning results indicate that the novel cellulose-based fibers can provide a renewable and recyclable alternative, for example, spun-laid PP in several hygienic textile and fully oriented in technical applications in future.     

再生纤维素纤维的研究进展

概述了再生纤维素纤维的研究现状;详述了高湿模量粘胶纤维、Lyocell纤维、铜氨纤维、醋酯纤维、秸秆类可再生纤维素纤维、再生竹纤维、再生麻纤维的性能、结构特征及其适用性;探讨了我国再生纤维素纤维的发展趋势,指出超天然的功能再生纤维素纤维材料将成为未来发展的重点,我国应注重开发差别化、功能化粘胶纤维。     

Surface Characterization of Differently Pretreated Flax Fibers and Their Application in Fiber-Reinforced Composites

Strong natural bast fibers, especially flax fibers, can be used to replace glass fibers in reinforced composites. The properties of natural fibers depend largely on maturity, retting and processing. Two chemical treatments were applied to retted and semiretted flax fibers to create better fiber to resin bonding and to show the effect of retting degree and successive purification processes on the mechanical properties of natural composite materials. Retted and semiretted flax fibers have been scoured and bleached with the objective of removing surface impurities and developing finer structure. To investigate the effect of adhesion promoter on the mechanical properties of natural fiber composite, a composite sample was prepared from bleached retted flax pretreated with adhesion promoter Isostearoyltitanate (ISTT).

After treatments the fibers got cleaner and the measurements showed that the fiber fineness as well as the surface free energy increased. The treatments were accompanied by decrease in the fiber tenacity but it has been found not to be reflected to the final mechanical properties of the composite. No improvement was remarked by using Isostearoyltitanate for surface modification.     

Effects of flocculants and sizing agents on bending strength of fiber cement composites

Wood fiber is used to replace asbestos in the manufacture of fiber cement due to its high availability, low cost and good reinforcement properties. The different chemical composition of the cellulose fibers makes its compatibility with the cement much more complex than that of asbestos fibers. In the Hatschek process a suitable flocculant is needed when using cellulose fibers. The right selection of the flocculant is crucial due to its effect on mineral fines retention, dewatering and formation and, as a consequence, on the overall efficiency of the machine. This paper shows how anionic poly-acryl-amides (A-PAM), the most common flocculants used in Hatschek machines, have a negative effect on the bending strength properties of fiber cement sheets. In order to overcome this problem fiber surface treatment, with sizing agents, is proposed in this paper. Sizing with styrene-acrylate copolymers and alkyl ketene dimer produces an increase in bending strength properties.     

服用丙纶纤维新品种与技术

８０年代以来,在其它纤维品种呈零增长或负增长的形势下,两轮纤维得到了迅猛发展,服用丙纶新品种新技术层出不穷,细旦丙纶、可染丙纶、阻燃丙纶、远红外丙纶、抗紫外线丙纶、抗菌丙纶、中空丙纶和芳香丙纶等均得到了良好的开发。针对天津的石油化工和纺织工业基础,及早研究开发丙纶新技术,对促进我市经济发展有积极意义。     

再生聚酯纤维在不同夹持方式下的拉伸性能研究

分别测试了再生聚酯纤维和普通涤纶在三种夹持方式(直接、结节和钩接)下的拉伸断裂性能,从而研究了夹持方式对两种纤维拉伸断裂性能的影响。测试结果表明:两种纤维在直接拉伸方式下的拉伸断裂性能都要优于其它两种方式,这是由纤维弯曲伸直差异、应力集中现象以及弱环定律的原因造成的,且在钩接方式下进行拉伸时应力集中现象更为明显;再生聚酯纤维和普通涤纶的拉伸断裂性能存在一定的差异,特别是断裂伸长率和断裂功差异较大,且再生聚酯纤维的断裂强度受夹持方式的影响更大。     

阻燃纤维性能及其变化探析

对阻燃纺织材料的基本性能进行了分析,介绍了阻燃纤维的阻燃机理,通过阻燃纤维梳理前、后出现长度与强度的变化对阻燃纤维性能进行了研究,以期对今后阻燃纤维的发展有所帮助,降低其火灾的发生率。     

Melt-spun liquid core fibers: physical and morphological characteristics

Application of different polymers and fillers in multi-component fibers has recently emerged as an effective approach in textile industries. Recent investigations have extensively demonstrated that hollow fibers can be melt-spun and subsequently filled with liquids; however, introduction of a liquid into a fiber core and filling it up with that liquid, specifically at extended lengths, remains challenging. In this study, based on the results previously obtained for the simulation and extrusion of polymer melt and liquid co-flowing, continuous production of the liquid core bi-component filaments via melt spinning through specially designed spinneret is discussed. In fact, core/shell bi-component filaments 50 μm in diameter consisting of polypropylene sheath and complex ester core were produced undergoing 1500 m/min continuous melt spinning with drawing ratio of 5. Physical properties of the developed fibers were investigated which were in acceptable condition with those of the reference solid and hollow fibers. Successful presence of a liquid in an eccentric channel 15 μm in diameter was demonstrated by microscopic observation. Furthermore, the ester oil was retained inside the fiber due to its low contact angle against polypropylene, thereby resolving the need for sealing the fiber’s outlet. Also, TGA and FTIR analysis confirmed the presence of liquid inside the bi-component fibers. DSC tests showed a similar crystallinity for liquid core and hollow fibers, which was about 37 %, while solid fiber had 5 % more crystallinity. Due to the vast available liquids and polymers with various properties, developed liquid core fibers will provide a suitable platform for a large number of applications in future.