剑麻纤维爆破法制浆和抄造性能的研究

本文采用蒸汽爆破制浆的方法，对剑麻原料进行制浆的研究。制得了得率高、强度好的剑麻爆破浆。分析了剑麻在蒸汽爆破前后纤维形态的变化，并对剑麻的爆破浆及其化学浆的抄造性能进行了比较。结果表明，爆破法剑麻浆是一种良好的造纸原料。     

Effect of grafting generations of poly(amidoamine) dendrimer from the sisal fiber surface on the mechanical properties of composites

In order to improve the mechanical properties of sisal fiber-reinforced polypropylene composites, the sisal fibers were grafted with poly(amidoamine) dendrimer and the effects of grafting generations on the mechanical properties of composites were studied. The results reveal that the tensile, flexural, and impact strength of the composites are improved considerably with the poly(amidoamine) dendrimer grafting treatment. For the 2.0 generation treatment with the poly(amidoamine) dendrimer, the tensile, flexural, and impact strength of the composites at 30 wt% fiber loading increase by 29%, 13%, and 54%, respectively. However, the thermal and mechanical properties of the sisal fibers decrease after prolonged grafting treatment.     

Effect of Process Parameters on Grafting Ratio and Thermal Stability of Lactide-Grafted Sisal Fiber

Polylactide (PLA) was grafted onto sisal fiber (SF) on the basis of the principle of lactide coordinative ring-opening polymerization. The orthogonal test was done to investigate which process parameter affected the grafting ratio mostly. Then the thermal stability of lactide-grafted sisal fiber (SF-g-LA) was studied. Results demonstrated that the lactide was grafted on sisal fiber surface and initiator amount was found to be the most important determinant of the grafting ratio. After grafting copolymerization reaction, the thermal stability of sisal fiber decreased. The increase of grafting ratio does not decreased the thermal stability of SF-g-LA.     

Physical Properties of Plant Fibers (Sisal,Coir) and Its Composite Material with Tamarind Seed Gum as Low-Cost Housing Material

In this study, the physical properties of sisal and coir fibers have been described. Using manual extraction procedures, the sisal fibers were extracted from the sisal plant and coir fibers from the coconut palm. Thermal analysis by differential scanning calorimetry, structural morphology by scanning electron microscopy, and the degree of sharpness of the equatorial reflections of the X-ray fiber diffraction pattern were recorded for the untreated sisal and coir fibers. Tensile strength was determined for the single fiber and the results are correlated with the tensile strength of bundle fibers. Composite material has been prepared with this plant fiber as a filler and tamarind seed gum as a matrix material. The endosperms of roasted tamarind seeds were used for the preparation of tamarind seed gum solution. The different temperature condition maintained for roasting the seeds are 130°C, 160°C, and 180°C. The tensile strength of the prepared composite material is measured and it shows dependency of the roasting temperature condition of the tamarind seed. Scanning electron microscopy and water resistivity test were conducted, and the results were reported for the prepared composite material. Low-cost housing is made using this biodegradable sisal fiber--tamarind seed gum composite material.     

Long-Unidirectional Palm and Sisal Fibers Reinforced Composite: An Experimental Investigation

This paper focuses mainly on investigating the mechanical properties of mortar reinforced with long-unidirectional vegetable fibers such as palm fibers and sisal fibers. The mechanical properties of fibers are also studied by considering fiber tensile test and fiber coupling test to analyze the twist-extension coupling and the tensile strength. Fibers were manually extracted from palm and sisal leaves. Laminated mortar specimens with fibers volume fraction ranging between 0% and 1.95% were prepared. The long unidirectional oriented fibers were placed on the lower part of the mortar. The influence of curing conditions on flexural strength of laminated mortar specimens was analyzed by considering two curing conditions: WCCC (wet chamber curing condition) and LCC (laboratory curing condition). Results confirm that the optimum fiber volume fraction was evaluated as 1.4% for Palm fiber-reinforced mortar. Better mechanical performance was accorded to the Palm fiber reinforced mortar in WCCC case due to the availability of water which is necessary to cement hydratation. Long Sisal fiber submitted to a tensile load shows coupling phenomenon between twist and extension which has a mechanical effect on the matrix behavior.     

剑麻纤维制浆性能的研究

本文分析了剑麻的纤维形态和化学组分 ,进行了剑麻烧碱—AQ法和添加助剂和 /或亚硫酸钠的烧碱—AQ法蒸煮 ,制得了得率高、强度好的剑麻浆     

Mechanical,Thermal, and Interfacial Characterization of Randomly Oriented Short Sisal Fibers Reinforced Epoxy Composite Modified with Epoxidized Soybean Oil

Short sisal fibers were reinforced in epoxidized soybean oil (ESO) modified toughened epoxy blends to improve the mechanical and thermo mechanical properties. Tensile modulus and tensile strength of the composite with 15 wt% sisal fiber were found to be increased as compared with bio-based epoxy blend. From DTG analysis, rate of degradation peak is found to be shifted to higher temperature revealing enhanced thermal stability of composite over base matrix. Dynamic mechanical analysis predicted higher storage modulus and higher glass transition temperature of bio-based epoxy composite. Scanning electron micrographs showed strong fiber-matrix adhesion. Contact angle measurement reveals the hydrophilic character of bio-based epoxy composite     

Effects of Coir Fiber and Maleic Anhydride Modification on the Properties of Thermoplastic Starch/PLA Composite Laminates

Coir fiber reinforced composite laminates made of poly(lactic acid) (PLA) with a thermoplastic starch (TPS) were fabricated. Modified thermoplastic starch (MTPS) was prepared by reactive blending of TPS with maleic anhydride (MA). The effect of coir fibers was of our main interest. The tensile properties, water absorption, and morphological properties of the fabricated composite laminates were investigated. The composite laminates between PLA and starch TPS were prepared using coir fiber as reinforcing core, and the physical, mechanical, and morphological properties were studied. The results suggested that the optimum fiber contents for maximum tensile strength for TPS/PLA and MTPS/PLA composites were 20 and 30 wt%, respectively. Using MA for chemical modification of TPS for PLA composites could reduce the PLA content of about 10 wt%, and improve the tensile about 20%. The volume swelling for the MTPS/PLA composites was much lower than that for the TPS/PLA composites, and the swelling reduced with increasing coir fiber content. Based on compressive strength, the pallets produced using MTPS/PLA composites showed a high potential to replace the commercial urea-formaldehyde/PLA composites. It clearly appeared that MA modification to TPS not only improve the mechanical properties of fiber reinforced PLA composites, but also made the PLA composites bio-degrade more quickly.     

聚乳酸/聚丙烯共混纺粘纤维的制备及其性能

为探寻聚乳酸用量对聚乳酸（PLA）/ 聚丙烯（PP）共混纺粘纤维性能的影响,以PLA和PP为原料,采用实验室纺粘小样机制备了多种混比的PLA/PP共混纺粘纤维。采用扫描电子显微镜、电子单纤维强力仪、恒温烘箱、接触角测试仪、X射线衍射仪对所得各种纤维的形态特征、力学性能、吸湿性、接触角、结晶度进行测试和分析。结果表明：随着PLA含量的增加,共混纤维的强力下降,断裂伸长增加,但断裂功基本保持不变;随着PLA含量的增加,纤维的回潮率增加,接触角减小,结晶度下降;PLA质量分数为7%的共混纺粘纤维较纯PP纺粘纤维的结晶度下降21%,吸湿性则达到纯PLA, 可在不降低其耐用性的同时,提高其吸湿性能。     

Effects of Different Modification Methods on the Properties of Sisal Fibers

ABSTRACT

In this paper, sisal fibers were modified by different methods such as alkali treatment, γ-aminopropyltriethoxysilane treatment, tetraethylorthosilicate (TEOS) sol-gel treatment, TEOS, and silane combination treatment. The effects of different modification methods on the properties of sisal fibers were studied by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and universal material testing machine. The results show that the combination treatment fiber has the best heat resistance and the most obvious improvement in tensile properties, the tensile strength and modulus increase by 31.58% and 15.82%, respectively.     

聚乳酸/聚(3-羟基丁酸酯-co-3-羟基戊酸酯)共混纤维的结构及其织物染色性能

聚乳酸(PLA)与聚(3-羟基丁酸酯-co-3-羟基戊酸酯)(PHBV)共混纺丝是改善聚乳酸(PLA)纤维的耐热性和柔韧性的方法之一。为了揭示共混纤维结构对其织物染色性能的影响规律,借助热重分析仪、差示扫描量热仪、X射线衍射仪等手段分别对共混纤维和PLA纤维的微结构和热性能进行分析。采用高、中、低温3类分散染料,对2类纤维织物的染色升温速率曲线、提升性和各项染色牢度等性能进行了比较。结果表明：共混纤维中PLA与PHBV两相分离,PLA相具有与PLA纤维相似的晶型结构,其结晶度较高,而PHBV相中形成较低的结晶;与PLA纤维相比,共混纤维的熔点较高,玻璃化温度稍低,因此其能在较低的温度下达到上染平衡;在相同的染色条件下,共混纤维织物的表观染色深度几乎是PLA织物的2倍;2类纤维织物的耐皂洗色牢度性能均不够理想。     

聚乳酸和涤纶纤维的鉴别方法

对聚乳酸(PLA)和聚对苯二甲酸乙二酯(PET)纤维的鉴别方法进行了探讨。结果表明,PET纤维具有比PLA纤维更致密的结构,有些PLA纤维横截面上的孔洞或裂缝用生物显微镜就能观察到。PET和PLA纤维的红外吸收光谱有明显的差别,在差热性能上,PET纤维的熔融温度和峰顶温度比PLA纤维的分别高90℃和84℃。碱性条件下(pH值为11.8)对PLA纤维的强度有明显损伤,而对PET纤维的强度损伤并不明显,这种性能也可以用来进行对2种纤维的定性鉴别。     

表面接枝聚乙烯吡咯烷酮的聚乳酸纤维改性

针对聚乳酸（PLA）纤维的强疏水性,对聚乳酸纤维表面接枝聚乙烯吡咯烷酮进行研究。通过万能强力仪、红外光谱仪,扫描电子显微镜对改性聚乳酸纤维进行力学性能和结构的表征,并对纤维水解质量减少率、改性纤维吸水率和接枝率进行测定。结果显示,碱水解和酸水解之后的PLA纤维均成功地接枝聚乙烯吡咯烷酮（PVP）;但是碱水解的聚乳酸纤维接枝PVP的接枝率低于酸水解的聚乳酸纤维;2种接枝PVP的聚乳酸纤维吸水率明显提高,分别是未改性聚乳酸纤维吸水率6.44倍和8.97倍,但是接枝的聚乳酸纤维的力学性能均下降。     

静电纺聚乳酸纤维毡的微观结构及力学行为

通过静电纺丝可以制备由直径为数微米的聚乳酸纤维构成的多孔状材料。在确定纺丝工艺条件的基础上,分析接收基底对PLA纤维毡微观结构和力学性能的影响。研究结果表明:质量分数为11%的聚乳酸/二氯甲烷溶液可以利用静电纺纺出连续光滑且比较均匀的纤维;当以纳米级的静电纺丝素或锦纶纤维毡为基底时,可以使PLA纤维的分布均匀化,同时纤维的直径下降;经过复合后,PLA复合纤维毡承受负荷的能力得到了很大提高。     

Some Properties of Natural Fibers (Sisal,Pineapple, and Banana) in Comparison to Man-Made Technical Fibers (Aramide,Glass, Carbon)

In this paper, we analyze the results of the delignification treatments performed on three natural fibers (sisal, pineapple, and banana) and of the thermal treatments at 400, 600, and 800°C on three industrial fibers (aramid, carbon, and glass). The fibers were analyzed by TGA, SEM, and EDS, as well as tested for tensile strength before and after the delignification and thermal treatments. Contact angle measurements were also carried out on the natural fibers. With the delignification treatments, the removal of Si, K, and Mg on pineapple and banana fibers was achieved. Thermal treatments lowered significantly the tensile strength of industrial fibers, while delignification treatments decreased slightly the mechanical resistance of natural fibers, except in the case of the pineapple fiber.     

聚乳酸/百里酚抗菌纤维的制备与性能

为开发一种绿色环保可降解的抗菌纤维，将具有良好生物可降解性的聚乳酸(PLA)与天然抗菌剂百里酚采用温控共混装置混合均匀后，利用熔融纺丝法制备PLA抗菌纤维。借助扫描电子显微镜、傅里叶变换红外光谱仪、 X射线衍射仪、单纤维强力测试仪及综合热分析仪等研究了不同质量分数百里酚对PLA抗菌纤维表观形貌、化学结构、结晶结构、热学以及力学性能的影响，并利用振荡烧瓶法测试纤维的抗菌性能。结果表明：在成纤过程中，百里酚会附着在纤维外表面发挥抗菌作用；随着百里酚质量分数的增加，PLA抗菌纤维的热分解温度和熔融温度逐渐降低，断裂伸长率先增加后缓慢减小，最高可达320.98%,是纯PLA纤维的50～90倍；另外，随着百里酚质量分数的增加，PLA抗菌纤维的结晶度逐渐增大；当百里酚质量分数大于15%时，PLA抗菌纤维的抑菌率达到99.99%以上，可完全抑制金黄色葡萄球菌和大肠杆菌的生长。     

Effect of Alkyl Phenol from Cashew Nutshell Liquid and Sisal Fiber Reinforcement on Dry Sliding Wear Behavior of Epoxy Resin

A phenalkamine made from the reaction of alkyl phenol from cashew nut shell liquid (CNSL) and alkaylamine was added at three different weight percentages (30%, 40%, and 50%) as a hardener for curing the epoxy polymer. The effect of phenalkamine concentrtation on mechanical and dry sliding wear resistance properties were compared to synthetic aliphatic amine (TETA) cured epoxy network. It was obsererved that incorporation of phenalkamine improves the dry sliding wear resistance property of the epoxy network along with the impact strength and elongation properties. Epoxy composites incorporating sisal fiber placed unidirectionally (either parallel, anti-parallel, or perpendicular to the sliding direction) were prepared in a vacuum infusion process using phenalkamine as a crosslinking agent. It was observered that wear resistance of longitudinally oriented fibers composite was found to be higher owing to the area of fibers exposed to sliding asperities being smaller. With the goal to understand the brittleness behavior of epoxy networks, fractured surfaces of the epoxy networks were analyzed using optical microscope. A correlation was found between the mechanical and wear resistance properties of the epoxy networks.     

热处理对玉米纤维力学性能的影响

对玉米纤维进行不同方式的热处理实验,得出了热处理温度和热处理时间对断裂强度、断裂伸长、初始模量、断裂功的影响规律。研究结果表明:随着热处理温度的提高,玉米纤维的断裂强度逐渐下降,断裂伸长率呈现逐渐上升的趋势;随着热处理温度和时间的增加,玉米纤维的初始模量逐渐下降;在温度不超过130℃时,温度对玉米纤维的力学性能影响不大,但在高温处理时力学性能显著变差,温度和时间对力学性均有影响,热处理时间超过20 min,力学性能显著变差。     

聚乳酸纤维在湿法非织造材料生产中的抄造性能

聚乳酸(PLA)纤维是一种新颖的绿色环保纤维,具有众多优异性能。实验通过对PLA纤维(单组分、双组分)、低熔点聚酯(PET)纤维、水溶性聚乙烯醇(PAV)纤维混合湿法抄造纸张性能的研究,探讨PLA纤维抄造非织造材料(功能纸)的可行性。结果表明,单组分PLA纤维的熔融温度高,单独湿法抄造时成形困难;双组分PLA纤维、PET纤维、PVA纤维因其熔融温度低,与单组分PLA纤维混合抄造时,能起到有效的黏结作用;PET纤维的黏结效果优于双组分PLA纤维,PVA纤维的加入有利于纸张强度的进一步提高。     

商业化生产的几种INGEO~(TM)聚乳酸纤维

INGEOTM聚乳酸纤维具有生物降解性,比其他植物纤维高的强度和导湿性,天生的阻燃性和不滋生细菌的特性。介绍了实现商业化生产的聚乳酸纤维的性能指标、纤维类别及其用途。