黄麻纤维毡增强复合材料的力学性能研究

文章对黄麻纤维进行表面处理,并制作纯黄麻纤维以及与碳纤维混杂的针刺毡;采用真空辅助树脂传递模塑法制备黄麻纤维毡增强乙烯基树脂复合材料,并测试其力学性能.结果表明:碱处理和双氧水处理后黄麻纤维表面杂质被去除,复合材料的界面性能得到改善,综合力学性能得到提高;黄麻/碳纤维混杂增强复合材料的拉伸性能提高更为显著,拉伸强度和拉伸模量比未处理纤维毡增强复合材料分别增加了146.2%和43.6%,但其弯曲性能却低于其他两种处理后的黄麻增强复合材料.     

黄麻纤维毡的表面处理及其增强复合材料的力学性能

用3种不同的化学处理剂,碱、KMnO4和A-151硅烷偶联剂分别对黄麻纤维针刺毡表面进行处理,采用真空辅助树脂传递模塑法制备黄麻纤维毡增强乙烯基酯树脂复合材料。借助动态接触角分析了黄麻纤维的表面能变化,并通过SEM观察了纤维表面和复合材料的拉伸断裂面。研究结果表明:经表面处理后,黄麻纤维表面能有所降低,纤维表面的微观结构发生变化,纤维与树脂的界面相容性得到改善,综合力学性能提高。经A-151硅烷偶联剂处理后,复合材料的力学性能提高最为显著,拉伸强度和弯曲强度分别提高了51.38%和77.46%。     

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。     

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。     

可降解黄麻/PBS复合材料的结构与力学性能

为解决当前环境污染和可持续发展问题,采用模压成型工艺制备可降解黄麻/PBS复合材料,通过拉伸、弯曲性能测试、红外分析和SEM观察,探讨纤维含量和碱处理对材料性能的影响。结果表明:随着纤维含量的增加,复合材料的拉伸强度先增大后减小,在纤维含量为10%时达到最大值,比纯PBS提高了30.1%;拉伸模量、弯曲强度和弯曲模量均随纤维含量的增大而提高,在纤维含量为30%时分别比纯PBS提高了24.2%、185.5%和107.7%。碱处理后黄麻纤维表面杂质被去除,表面部分刻蚀变粗糙,复合材料的综合力学性能得到提高,其中弯曲模量提高显著,比未处理的黄麻复合材料提高了58%。     

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 k J/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。     

麻/聚酯纤维混合针刺毡的制备与性能研究

采用苎麻落麻、黄麻、聚酯纤维按照不同混合比例制备针刺毡,研究其透气性能、力学性能和热学性能。研究结果表明:黄麻/苎麻针刺毡均具有较好的透气性能,苎麻纤维的加人使得针刺毡的透气率大大下降,而黄麻纤维的加入能够提高苎麻和聚酯纤维针刺毡的透气率;麻纤维与聚酯纤维混合针刺毡的力学性能远远高于纯麻纤维针刺毡;不同比例针刺毡的热导率均较低,具有良好的保温性能;麻纤维的导热性能要优于聚酯纤维,纯苎麻针刺毡的热导率最高。     

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。     

黄麻-生物资源混杂纤维复合材料的制备及其机械和电学性能测定

混杂纤维复合材料由双苯酚-C-甲醛树脂和黄麻纤维并分别加上米壳、麦壳、甘蔗渣和树皮组成，制备条件：温度150℃，压力30．4MPa，时间2h。在复合材料中，树脂含量为纤维的50％。本试验测定了混杂复合材料的拉伸、挠曲、介电强度和体积电阻，并与黄麻／双苯酚-C-甲醛树脂单一复合材料的这些性能作了对比。结果表明，混杂复合材料的拉伸强度下降了53％～72％，这主要是由于混杂复合材料中三明治式的无规排列造成的；挠曲强度，除了黄麻／米壳混杂复合材料下降了26％，其它的提高了53％～72％；介电击穿强度没有太大的变化（1．89-2．11kV／mm），但体积电阻的变化很大，黄麻／麦壳和黄麻／树皮混杂复合材料的体积电阻提高了197％-437％，其余的两个稍有降低（2．3％-25．2％）。混杂复合材料拥有良好的机械性能和电学性能，可满足它们在低强、轻质工程上的应用，同样可以满足在低价房屋材料上的应用，例如隔离板、人造板。     

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。     

黄麻纤维增强混凝土的抗压和抗折性能研究

在混凝土中添加黄麻纤维,以增强混凝土的抗压和抗折性能。通过测定纤维增强混凝土的抗压和抗折强度,并与素混凝土进行对比,进而研究黄麻纤维的长度和掺量对混凝土的增强作用。结果表明:黄麻纤维长度为30mm,掺量为0.5～0.6kg/m3时,对混凝土的抗压及抗折强度增强作用最为显著。     

Fabrication and Characterization of MWCNT Filled Hybrid Natural Fiber Composites

Hybrid composites are fabricated by the combination of two or more fibers using a single matrix. It can be fabricated either with all of its constituents as natural fibers or with one or more constituents belonging to artificial fiber. The stacking sequence of the fibers in a hybrid composite can be altered resulting in a varying mechanical properties. In the present study the MWCNT filled banana-jute-flax fiber reinforced composites are investigated for its mechanical behavior by varying the stacking sequence of the fiber layers and weight % of Multi-Walled Carbon Nano Tube (MWCNT). A Modified resin was prepared by adding MWCNT in the epoxy resin using ultrasonic probe sonicator and a hybrid composite is fabricated with it by using compression moulding processes. The mechanical properties are evaluated as per the ASTM standards. The incorporating of MWCNT and the stacking sequence of fiber layers shows the greater impact on the mechanical properties. The composites of jute fibers at the extremities (JBFBFBFJ) exhibiting the enhancement of tensile, compressive and hardness properties than the flax fiber at the extremities (FBJBJBJF) and it could be used in various automobile applications. Microstructure of the samples are investigated by Scanning Electron Microscope (SEM)with Energy dispersive X-ray (EDS). The results indicate that increasing the weight % of MWCNT and varying the stacking sequence of fibers improves the mechanical properties of hybrid natural fiber composites.     

黄麻/热熔纤维针刺非织造材料的自然降解性能研究

分析了黄麻/热熔纤维针刺非织造材料在不同自然降解环境中的降解性能差异,通过测试其暴露于户外和土壤掩埋(潮土)两种环境中不同时间段后的质量损失率、拉伸强力和纤维之间的缠结状况,研究了其随降解时间变化的降解特性.结果表明:黄麻/热熔纤维针刺非织造材料随降解时间的增加在不同的时间段表现出不同的降解速率,质量损失率增大,外貌形...     

Effect of Rot-Retardant Treatment on Properties of Jute Fibers

Jute natural fiber is gradually replacing traditional glass fibers as reinforcement in composites due to their higher specific modulus and lower specific gravity. For reducing rotting properties of jute fiber, rot-retardant treatment was conducted on different portions of the fiber. The rot-retardant jute fibers were characterized by tensile test, Fourier transform infra-red spectroscopy, scanning electron microscopy, X-ray diffraction analysis, and thermal and water absorption tests. The tensile properties improved in the middle portion as compared to the top and bottom portions and deteriorated after rot-retardant treatment. The diameter gradually increased from top to middle and then to bottom portion after treatment. The crystalinity index was found higher for bottom portion. Thermal properties of jute fiber also improved as compared to the control jute fiber. The rot-retardant--treated jute fiber may find satisfactory and desirable application in our house hold accessories.     

Studies on Mechanical and Morphological Characterization of Developed Jute/Hemp/Flax Reinforced Hybrid Composites for Structural Applications

In the present study, an attempt has been made to develop and characterize natural fiber-based composites (jute/epoxy, hemp/epoxy, flax/epoxy) and their hybrid composites (jute/hemp/epoxy, hemp/flax/epoxy, and jute/hemp/flax/epoxy) using hand-lay-up technique. Mechanical characterization (tensile, flexural, impact, and hardness test) of the developed composites was performed. The interface between fiber and matrix was examined using scan electron microscopy (SEM). Among (jute/epoxy, hemp/epoxy, flax/epoxy), flax/epoxy composite has shown higher hardness (98 Shore-D) and tensile strength (46.2 MPa) whereas better flexural and impact strength have been shown by hemp/epoxy (85.59 MPa) and jute/epoxy (7.68 kJ/m²) composites respectively. Results showed that hybrid composites observed better mechanical properties. Jute/hemp/flax/epoxy hybrid composite showed the highest tensile strength, modulus and impact strength of 58.59 MPa, 1.88 GPa, and 10.19, kJ/m², respectively. Jute/hemp/epoxy hybrid composite achieved the maximum flexural strength of 86.6 MPa.     

Hybrid Composites Made from Jute/Coir Fibers: Water Absorption,Thickness Swelling,Density, Morphology,and Mechanical Properties

The action of water in natural fiber-reinforced composite material was studied so as to produce great swelling with resultant changes in the fine structure, dimensional stability, and mechanical properties. Water absorption and thickness swelling test reveal that hybrid composite shows water absorption moderately, which is 15.3% for hybrid coir/jute/coir composite and 11.2% for hybrid jute/coir/jute composite. The thickness swelling, water absorption, and mechanical properties of the hybrid composites slightly increased as the layering pattern of hybrid composites changed. Hybridization of coir fibers composites with jute fibers can improve the dimensional stability, extensibility and density of pure coir composites. Microstructures of the composites were examined to understand the mechanisms for the fiber-matrix interaction in relation to mechanical properties.     

Experimental Investigation of Load Settlement Behavior of Coir Mat and Coir Fiber Reinforced Sand

An experimental study in terms of model footing test were performed to comparatively assess the effect of form of reinforcement, viz., mat and fiber, on the load intensity response of reinforced sand. Coir reinforcement was used in this present investigation to assess comparative performance of coir mat and coir fiber reinforced sand, as it is highly durable among all other natural materials. Model footing test were conducted by placing coir mat and coir fiber at different u/B ratios. Load deformation behavior was compared with the help of peak strain, bearing capacity ratio and settlement reduction factor. The experimental and calculated theoretical values of peak stress of coir mat reinforced sand were compared and found that both the values were in good agreement with predicted values. The results of the present experimental investigation indicated that the form of reinforcement viz., mat/grid and fibers has significant influence on load deformation behavior of reinforced sand. Coir mat when located within the failure zone intercepting the shear zone below the loaded footing is most beneficial in terms of load carrying capacity of reinforced sand, in consistent with earlier investigations. However maximum increase in bearing capacity of coir fiber reinforced sand does indicate an optimum u/B ratio of 1.0. Maximum SRF for coir mat reinforced sand corresponds to u/B = 0.6 where for coir fiber reinforced sand it corresponds to u/B = 1.0.     

Interdependence of moisture,mechanical properties,and hydrophobic treatment of jute fibre-reinforced composite materials

Despite cheap and sustainable in nature, the use of natural fiber composites is limited due to their high moisture absorption, poor fiber–matrix interface, and lack of data on evolution of properties when subjected to environmental factor such as temperature and humidity. The aim of this research is to study the interdependence of moisture regain, hydrophobic treatment, and the mechanical properties of jute fiber-reinforced composite materials. Composite samples made from treated and untreated jute fiber-reinforced composites were exposed to humid environment and their moisture regain, mechanical properties and fiber-matrix interface was tested at given time intervals until four weeks. The composites produced with hydrophobic treated reinforcement showed lesser moisture regain and improvement in the tensile and flexural strengths compared to untreated fabric composite. A clear improvement in fiber-resin interface was observed by scanning electronic microscopy. The dynamic mechanical analysis of treated and untreated composites was conducted in a temperature range 20–140 °C. An increase in the storage modulus of treated composite materials was noted as compared to untreated ones. Furthermore, it was concluded that developed composite loss their mechanical properties linearly with immersion time. However, this aging was slow in treated fabric composites especially hybrid fluorocarbon and fluorocarbon.