黄麻纤维/ES纤维复合材料制备及力学性能分析

将黄麻纤维与ES纤维通过针刺非织造工艺制备成非织造布,再经过热压工艺制备成黄麻纤维/ES纤维复合材料,分析了黄麻纤维/ES纤维质量比和黄麻纤维碱处理对复合材料力学性能的影响。通过试验发现,复合材料的拉伸强度与弯曲强度都随复合材料中黄麻纤维的质量分数增加而呈现出先增加后减小的趋势;对于黄麻原麻/ES复合板材,比例为15/85、20/80时,其拉伸强度和弯曲强度最大,纵、横向拉伸强度达到33.69、28.43 MPa,纵、横向弯曲强度达到最大值36.28、31.75 MPa;对于黄麻碱处理/ES复合板材,比例为25/75、30/70时,其拉伸强度和弯曲强度最大,纵、横向拉伸强度最大达到41.06、39.47 MPa,其纵、横向弯曲强度达到最大值49.96、40.38 MPa。试验表明,碱处理提高了黄麻纤维和ES纤维之间的相容性,提高了界面结合强度,碱处理后的黄麻纤维增强ES纤维复合材料的力学性能优于未处理前。     

三维玻璃纤维织物增强不饱和树脂的力学性能研究

以不饱和树脂为基体,三维玻璃纤维织物为增强体,采用手糊/模压工艺,制得三维玻璃纤维增强复合材料,并对其力学性能进行了研究。结果表明,当增强材料的质量分数为10%时,复合材料的拉伸强度和弯曲强度分别为89.38MPa和147.45MPa。与二维玻璃纤维织物增强复合材料相比,其拉伸强度和弯曲强度分别提高了37.46%和21.91%,与短纤维增强复合材料相比,其拉伸强度和弯曲强度分别提高了64.30%和35.83%。另外,为进一步改善基体的力学性能,还考察了刚性粒子(碳酸钙)对复合材料的影响。结果表明,碳酸钙能提高复合材料的韧性,且当碳酸钙质量分数达到20%时韧性最佳。     

玄武岩纤维增强复合材料的制备及有限元分析

选取玄武岩纤维作为增强材料,聚丙烯(PP)为基体材料,采用模压工艺制备复合材料。采用单因子试验法研究了温度、压力及保压时间对玄武岩/PP复合材料力学性能的影响,结果表明:不同工艺条件对复合材料的力学性能有很大的影响,在成型温度190℃、成型压力10 MPa、保压时间10 min时制备的复合材料力学性能最佳,此时拉伸强度为267 MPa。运用有限元分析软件对最佳工艺条件下制备的复合材料进行拉伸过程计算机模拟,得出材料的模拟拉伸变形图,并与实际拉伸情况进行对比。有限元模拟表明,断裂发生在试件的平直段端部附近,采用此最佳工艺制备玄武岩/PP复合材料具有可靠性。     

3D打印玄武岩纤维增强聚乳酸基复合材料制备及性能

以聚乳酸(PLA)为基体,玄武岩纤维(BF)为增强体,采用熔融沉积(FDM) 3D技术来制备玄武岩纤维增强PLA(BF/PLA)复合材料试样,并研究了层高、打印速度和打印温度对复合材料力学性能的影响。结果表明:随着打印层高的增加,BF/PLA复合材料的纤维体积分数减小,拉伸强度和弯曲强度显著降低;随着打印速度增加,玄武岩纤维与PLA的包覆效果变差,试样拉伸强度和弯曲强度降低;随着打印温度增加,试样拉伸强度和弯曲强度略有增加。     

PES/CF/PET纤维混杂复合材料的力学性能

选用PES纤维作为基体，碳纤维(CF)作为增强体，聚对苯二甲酸乙二醇酯(PET)纤维作为黏合剂，利用特殊的铺层结构制备出一种低密度、易加工、可回收的复合材料。采用正交试验设计研究了PES纤维质量分数、热压温度、压力和时间对复合材料拉伸性能的影响，并对材料的断裂机制进行了分析。结果表明：PES纤维质量分数是影响复合材料拉伸强度的最主要因素，其次是热压时间，热压温度和压力的影响最小；当PES纤维质量分数为55%、热压温度为270℃、压力为25 MPa、时间为50 min时，PES/CF/PET纤维混杂复合材料具有良好的力学性能，拉伸强度达到59.526 MPa,拉伸模量达到1.576 GPa,断裂伸长率达到6.950%;复合材料拉伸断裂机制主要表现为纤维的断裂。     

黄麻纤维非织造布增强不饱和聚酯树脂复合材料力学性能研究

为了探讨黄麻纤维非织造布/不饱和聚酯树脂复合材料的力学性能,将黄麻纤维通过针刺工艺制备成非织造布,并对其进行碱处理,制备了不同黄麻纤维质量分数的复合材料,测试了复合材料的拉伸弯曲性能,并采用扫描电镜测试了复合材料的断面形态,分析了黄麻纤维针刺非织造布质量分数与碱处理对复合材料拉伸强度与弯曲强度的影响。结果表明:黄麻纤维针刺非织造布对不饱和聚酯树脂的力学性能具有明显的增强效果,且随着黄麻纤维质量分数的增加,复合材料的力学性能先增加后减小,当黄麻纤维/树脂质量比为20/80时,复合材料的拉伸强度和弯曲强度均达到最大,其中碱处理黄麻纤维针刺非织造布增强复合材料的拉伸强度为41.78 MPa,弯曲强度为59.03 MPa;碱处理后黄麻纤维的表面性能得到改善,使得黄麻纤维与聚酯树脂的界面结合情况得到改善,从而提升复合材料的力学性能。     

弹性体对棉秆纤维/PLA复合材料的增韧研究

以棉秆纤维为增强材料、聚乳酸(PLA)为基体材料及不同质量分数的聚氨酯热塑性弹性体(TPU)和聚烯烃弹性体(POE)分别为增韧剂,通过熔融共混的方式制备棉秆纤维/PLA复合材料,然后测试复合材料的力学性能,并观察其断裂形貌,探讨弹性体对棉秆纤维/PLA复合材料的力学性能的影响。结果显示,POE的增韧效果优于TPU,当POE的质量分数为8%时,棉秆纤维/PLA复合材料的冲击强度达到0.77 J/cm2、弯曲强度达到114.729 MPa,分别比未添加弹性体时提高250.00%、95.88%。     

香蕉纤维增强不饱和聚酯树脂复合材料的制备工艺研究

利用热压成型法制备香蕉(茎)纤维增强不饱和聚酯树脂复合材料,结合单因素分析法和正交法研究热压工艺三大要素:压力、温度和时间以及纤维含量等工艺条件对增强复合材料力学性能的影响,确定最佳的制备工艺。结果表明:在压力、温度和时间分别为13 MPa、150℃、11 min的热压参数值下以及纤维的添加量为20%时复合材料的力学性能最佳,与纯树脂相比,拉伸强度提高了71.8%,弯曲强度提高了49%。     

铺层角度对苎麻纤维复合材料性能的影响

基于真空辅助成型工艺,研究铺层角度对苎麻织物增强环氧树脂复合材料力学性能的影响,并将该铺层设计应用在复合材料桥梁模型上。结果表明:当铺层方式为纬向铺层(90°)时,复合材料的拉伸强度最大,为73.5 MPa;经纬交叉铺层(0°/90°)时,为72.4 MPa。当铺层方式为经纬交叉铺层时,复合材料的拉伸模量、弯曲强度、弯曲模量和剪切强度皆为最大,分别为3.8 GPa、108.2 MPa、5.0 GPa和21.7 MPa。综合拉伸、弯曲、剪切性能,经纬交叉铺层复合材料力学性能最优。苎麻纤维复合材料桥梁的最大载荷为8.79 kN,载荷质量比为12.08。     

造纸法制备碳纤维增强热塑性复合材料的研究

本研究以短切碳纤维为增强体,聚丙烯(PP)纤维为基体,采用湿法造纸工艺制备碳纤维增强热塑性复合材料(CFRTP)。通过正交实验,探讨了碳纤维含量、碳纤维长度、热压温度以及热压时间对CFRTP力学性能的影响。结果表明,碳纤维含量是影响复合材料力学性能的主要因素;正交实验条件下,当碳纤维含量20%,碳纤维长度5 mm,热压温度190℃,热压时间10 min时,CFRTP的性能最好,其拉伸强度为83.9 MPa,弯曲强度为52.5 MPa,缺口冲击韧性48.2 kJ/m~2,对比同等条件下未添加碳纤维的材料其性能分别提高了189%、52%以及1021%。同时,通过单一因素实验探究不同碳纤维含量对CFRTP力学性能的影响。结果表明,随着碳纤维含量的增加,CFRTP的拉伸强度、弯曲强度以及缺口冲击韧性均先上升后下降。     

碱处理对涤纶/光敏树脂复合材料力学性能的影响

针对光敏树脂经3D打印成型后试样力学性能较差问题,采用涤纶长丝增强光敏树脂的方法,使用光固化3D打印设备将涤纶长丝和光敏树脂复合成型制备涤纶增强复合材料。为获得较好的增强效果,对涤纶进行碱处理,研究了碱处理各条件下涤纶的减量率与纤维形貌和力学性能的关系,以及其对复合材料力学性能的影响。结果表明:随着减量率的增加,涤纶的形貌及力学性能改变越明显;当涤纶减量率为16.2%时,纤维表面出现连续纵向沟壑,力学强度下降6%,纤维的增强效果最好;经过改性处理的涤纶增强复合材料的拉伸强度和弯曲强度分别达到78 MPa和471 MPa,相比于未处理的纤维增强复合材料分别提升了66%和336%。     

Morphology,Structure, and Mechanical Properties of Natural Cellulose Fiber from Mendong Grass (Fimbristylis globulosa)

This study was to investigate the morphology, structure, and chemical properties of the Mendong fibers extracted from Mendong grass (Fimbristylis globulosa) in the form of raw and treated fiber by alkali-included chemical content and functional group and to evaluate the strength and properties of Mendong fibers compared with other natural fibers. These studies explore the chemical properties of the fiber including fiber composition and functional group by FTIR, mechanical properties of fiber, and the structural and morphological analysis of the fiber using SEM and XRD. The results showed that the chemical contents of Mendong fibers were 72.14% cellulose, 20.2% hemicellulose, 3.44% lignin, 4.2% extractive, and moisture of 4.2%–5.2%. Mechanical properties of the fiber were a strong character with tensile strength of 452 MPa, and modulus of 17 GPa. The structural properties of Mendong fiber such as crystallinity, crystalline index, microfibril angle, and crystalline size were 70.17% and 58.6%, 22.9°, and 14.3 nm, respectively. This fiber has competitive advantages compared with other natural fibers and can be developed further as a potential reinforcement of polymer matrix composites.     

纤维增强对镁基复合板物理力学性能的影响

以玻璃纤维为增强材料,以镁基无机矿物质为基体材料,制备了新型纤维增强镁基无机复合板.研究了短切纤维、纤维网格布以及短切纤维结合纤维网格布3种增强方式对镁基复合板的物理力学性能和耐湿热性能的影响.结果表明,纤维增强方式对镁基无机复合板的密度、含水率、吸水率等性能影响较小,对复合板的力学性能和耐湿热尺寸稳定性影响较大,采用...     

Preparation of Polyimide Fiber/Thermoplastic Resin Composites with Improved Mechanical Properties

As a high-performance material for preparing composite materials, polyimide fibers suffer from many potential drawbacks, including poor bonding with other substrates, which results in composite materials with poor mechanical properties. Therefore, this study proposed a simple and rapid technique for obtaining loose, porous polyimide fiber papers by implementing a wet method using equal amounts of polyimide fiber and polyimide fiber paper as reinforcements, respectively. The polyimide resin-based composite materials were prepared by hand lay-up and hot pressing. The results showed that the paper-based reinforcement exhibited high porosity and the fibers were arranged with a uniform pore size distribution. The tensile properties, bending performance, and interlaminar shear performance of the paper-based composite improved by 130%, 108%, and 34.5%, respectively, compared to those of the fiber-based counterpart. The factors affecting the mechanical properties of the composites were analyzed based on the fiber length, fiber beating or lack thereof, and the basis weight of the paper. The increased uniformity of the polyimide fiber paper changed the ordering of the fibers and resolved drawbacks such as difficult dispersion, uneven pore size distribution, and poor mechanical properties related to single fibers in the resin-based composite material.     

碳纤维/聚丙烯/聚乳酸增强复合材料的力学性能

为在不改变碳纤维/聚丙烯(PP)复合材料力学性能前提下,降低复合材料中PP含量以减轻环境降解压力,通过在碳纤维/PP复合材料树脂体系中掺杂可降解的聚乳酸(PLA)形成共混树脂体系,并经热压成型制备碳纤维增强共混树脂复合材料。探究了PLA、PP共混体系质量比对复合材料冲击、弯曲和拉伸性能的影响。结果表明:随着树脂体系中PLA质量分数的增加,复合材料的冲击强度和弯曲强度都呈先降低后升高、再降低的趋势,拉伸强度呈现先升高后降低的趋势;当PLA质量分数为60%时,复合材料的冲击强度和弯曲强度最高,分别为21.8 kJ/m²和112.5 MPa,拉伸强度为37.2 MPa,复合材料的综合物理力学性能最优,与未添加PLA的复合材料的力学性能相近。     

不同结构厚截面三维机织碳纤维复合材料的弯曲性能对比

为准确分析不同结构厚截面复合材料不同方向上的弯曲性能差异,通过设计织造三向正交、浅交直联、浅交弯联3种典型机织结构的厚截面碳纤维三维机织物,并采用真空辅助树脂成型工艺制备了近似纤维体积含量的碳纤维复合材料板,对其进行了XYZ方向的弯曲实验。结果表明:三向正交结构由于内部纤维束近似平直,碳纤维束自身性能得到最大利用,对应复合材料经向弯曲强度最好;浅交直联结构复合材料的Z经和Z纬弯曲强度累加值最大,其厚度截面上的综合弯曲性能最好,且其他各方向的弯曲强度较为均衡;浅交弯联结构内部纱线交织摩擦损伤严重,且经纱屈曲程度最大,对应复合材料经纬向弯曲性能均为最差。     

A Review: Nanomaterials as a Filler in Natural Fiber Reinforced Composites

Composite reinforcement is defined as a technique to improve the engineering characteristics of composite and a fiber reinforced composite (FRC) is a composite material consisting of a polymer matrix imbedded with high-strength fibers, synthetic fibers or natural fibers. Natural fibers have recently become attractive to researchers, engineers, and scientists as an alternative reinforcement for FRCs. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nanoreinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to investigate natural fiber/nanofiller-based hybrid composite with specific concern to their physical and mechanical properties.     

Mechanical,morphological, and thermogravimetric analysis of alkali-treated Cordia-Dichotoma natural fiber composites

ABSTRACT

Usage of composites with natural fiber reinforcement is drastically increasing in recent times because of their low density, biodegradable nature, and low cost. However, natural fibers have certain core problems such as poor adhesion between the fiber and matrix and a relatively high degree of moisture absorption. Alkaline treatment of natural fibers is aimed at improving the adhesive strength so that effective stress transferability takes place in the composite. In the present work, Cordia-Dichotoma fibers were treated with sodium hydroxide (NaOH) and composites were prepared with different weight ratios of these fibers reinforced with epoxy. The prepared composites were tested for their tensile and flexural strengths (mechanical properties). Besides, for a comprehensive material characterization, IR spectroscopy (FT-IR), scanning electron microscope, and thermogravimetric analysis were carried out. This work investigates the influence of aforementioned NaOH treatment on thermal, mechanical, and morphological properties of the composite material.     

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.     

解键剂用于PBS-CTMP复合材料界面改性的研究

以解键剂对化学热磨机械浆（CTMP）进行预处理,然后通过熔融加工制备聚丁二酸丁二酯(PBS)-CTMP复合材料,对复合材料的力学性能、流变性能进行测试,并对其进行动态力学分析和形貌学表征。结果表明,解键剂处理削弱了CTMP纤维间的结合强度,以经解键剂处理后的纤维制备的复合材料力学性能显著提高。与未处理的CTMP相比,CTMP经质量分数0.50%(相对于纤维)的解键剂处理后,含质量分数40%CTMP的复合材料拉伸强度、冲击强度和弯曲强度分别提高了21.9%、22.3%和35.4%。解键剂的加入,降低了复合材料的剪切黏度,在复合材料体系中起到了润滑剂的作用,对其加工制备起到积极作用。DMA和SEM的分析结果表明,采用解键剂对CTMP进行处理后,CTMP纤维与PBS基体间的界面结合增强。