Progress Report on Natural Fiber Reinforced Composites

This century has witnessed remarkable achievements in green technology in material science through the development of natural fiber reinforced composites. The development of high‐performance engineering products made from natural resources is increasing worldwide day by day. There is increasing interest in materials demonstrating efficient use of renewable resources. Nowadays, more than ever, companies are faced with opportunities and choices in material innovations. Due to the challenges of petroleum‐based products and the need to find renewable solutions, more and more companies are looking at natural fiber composite materials. The primary driving forces for new bio‐composite materials are the cost of natural fibers (currently priced at one‐third of the cost of glass fiber or less), weight reduction (these fibers are half the weight of glass fiber), recycling (natural fiber composites are easier to recycle) and the desire for green products. This Review provides an overview of natural fiber reinfocred composites focusing on natural fiber types and sources, processing methods, modification of fibers, matrices (petrochemical and renewable), and their mechanical performance. It also focuses on future research, recent developments and applications and concludes with key issues that need to be resolved. This article critically summarizes the essential findings of the mostly readily utilized reinforced natural fibers in polymeric composite materials and their performance from 2000 to 2013.     

树脂基复合材料在汽车上的应用分析

轻量化、绿色环保和舒适安全性将成为我国汽车用材料未来发展方向,树脂基复合材料将是实现汽车轻量化、塑料化的材料之一.介绍了玻璃纤维毡增强热塑性复合材料(GMT)、长纤维增强热塑性复合材料(LET)、天然纤维增强热塑性复合材料(NMT)和碳纤维增强复合材料(CFRP)等的特点和应用实例分析.树脂基复合材料的应用是汽车轻量化设计和选材的发展趋势.     

Experimental Investigation of Mechanical and Morphological Properties of Flax-Glass Fiber Reinforced Hybrid Composite using Finite Element Analysis

The use of cellulosic fibers as reinforcing materials in polymer composites has gained popularity due to an increasing trend for developing sustainable materials. In the present experimental study, flax and glass fiber reinforced partially eco-friendly hybrid composites are fabricated with two different fiber orientations of 0° and 90°. The mechanical properties of these composites such as tensile, flexural and impact strengths have been evaluated. From the experiments, it has been observed that the composites with the 0° fiber orientation can hold the maximum tensile strength of 82.71 MPa, flexural strength of 143.99 MPa, and impact strength of 4 kJ/m². Whereas the composites with 90° fiber orientation can withstand the maximum tensile strength of 75.64 MPa, flexural strength of 134.86 MPa, and impact strength of 3.99 kJ/m². Morphological analysis is carried out to analyze fiber matrix interfaces and the structure of the fractured surfaces by using scanning electron microscopy (SEM). The finite element analysis (FEA) has been carried out to predict the resulting important mechanical properties by using ANSYS 12.0. From the results it is found that the experimental results are very close to the results predicted from FEA model values. It is suggested that these hybrid composites can be used as alternate materials for pure synthetic fiber reinforced polymer composite materials.     

Non‐traditional lightweight polypropylene composites reinforced with milkweed floss

Lightweight composites are preferred for automotive applications due to the weight restrictions and also due to the presence of inherent voids that can enhance the sound absorption of these composites. The density of the reinforcing materials plays a crucial role in such lightweight composites. Milkweed is a unique natural cellulose fiber that has a completely hollow center and low density (0.9 g cm^?3) unlike any other natural cellulose fiber. The low density of milkweed fibers will allow the incorporation of higher amounts of fiber per unit weight of a composite, which is expected to lead to lightweight composites with better properties. Polypropylene (PP) composites reinforced with milkweed fibers have much better flexural and tensile properties than similar PP composites reinforced with kenaf fibers. Milkweed fiber‐reinforced composites have much higher strength but are stiffer than kenaf fiber‐reinforced PP composites. Increasing the proportion of milkweed in the composites from 35 to 50% increases the flexural strength but decreases the tensile strength. The low density of milkweed fibers allows the incorporation of higher amounts of fibers per unit weight of the composites and hence provides better properties compared to composites reinforced with common cellulose fibers with relatively high density. This research shows that low‐density reinforcing materials can more efficiently reinforce lightweight composites. Copyright © 2010 Society of Chemical Industry     

Dependence of interfacial strength on the anisotropic fiber properties of jute reinforced composites

The upsurge in research on natural fiber composites over the past decade has not yet delivered any major progress in large scale replacement of glass fiber in volume engineering applications. This article presents data on injection‐molded jute reinforced polypropylene and gives a balanced comparison with equivalent glass reinforced materials. The poor performance of natural fibers as reinforcements is discussed and both chemical modification of the matrix and mercerization and silane treatment of the fibers are shown to have little significant effect on their level of reinforcement of polypropylene in comparison to glass fibers. A hypothesis is proposed to explain the poor performance of natural fibers relating their low level of interfacial strength to the anisotropic internal fiber structure. POLYM. COMPOS., 31:1525–1534, 2010. © 2009 Society of Plastics Engineers     

玻璃纤维增强酚醛摩阻材料

针对玻璃纤维增强酚醛摩阻材料存在的问题，研究分析了不同类型玻纤维增强酚醛树脂、玻纤增强橡胶改性酚醛树脂、下纤增强三聚氰胺腰果壳油改性酚醛树以及混杂纤维增强酚醛树脂摩阻材料的性能，并对摩阻复合材料的发展提出建议。     

Pretreatments of natural fibers and their application as reinforcing material in polymer composites—A review

In recent years, natural fibers reinforced composites have received much attention because of their lightweight, nonabrasive, combustible, nontoxic, low cost and biodegradable properties. Among the various natural fibers; flax, bamboo, sisal, hemp, ramie, jute, and wood fibers are of particular interest. A lot of research work has been performed all over the world on the use of natural fibers as a reinforcing material for the preparation of various types of composites. However, lack of good interfacial adhesion, low melting point, and poor resistance towards moisture make the use of natural fiber reinforced composites less attractive. Pretreatments of the natural fiber can clean the fiber surface, chemically modify the surface, stop the moisture absorption process, and increase the surface roughness. Among the various pretreatment techniques, graft copolymerization and plasma treatment are the best methods for surface modification of natural fibers. Graft copolymers of natural fibers with vinyl monomers provide better adhesion between matrix and fiber. In the present article, the use of pretreated natural fibers in polymer matrix‐based composites has been reviewed. Effect of surface modification of natural fibers on the properties of fibers and fiber reinforced polymer composites has also been discussed. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

聚丙烯复合材料声学特性研究进展

针对聚丙烯复合材料的声学特性,对近年此类材料的研究工作进行了回顾。以增强材料种类为区分,重点综述了玻纤增强聚丙烯复合材料、天然纤维/聚丙烯复合材料和无机填料聚丙烯复合材料吸隔声性能的相关研究,归纳了目前所报道的吸声材料的相关机理,总结了影响吸声性能的主要因素以及不同材料对不同频率噪声源的应用效果。     

Effect of saline degradation on the mechanical properties of vinyl ester matrix composites reinforced with glass and natural fibers

One important application of polymeric composites reinforced with natural fibers is in the area of naval engineering design. The objective of this work was to study the influence of saline degradation on the mechanical properties of vinyl ester matrix composites reinforced with glass, sisal, and coconut fibers and natural fibers modified with bitumen. All samples presented mass loss after exposure in a salt spray chamber. All materials, except the composite reinforced with coconut–bitumen, showed a decrease in toughness after a salt spray test. The fracture of the vinyl ester resin with sisal and sisal–bitumen fibers showed a fiber bridging mechanism. These materials showed the highest value of toughness among the materials studied. The presence of fiber pullout was observed in the samples of vinyl ester resin reinforced with glass, coconut, and coconut fibers covered with bitumen. In these samples, poor adhesion between the fiber and matrix was observed. The treatment of fibers with bitumen increased the mass loss and decreased the stability of samples in a saline atmosphere. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

植物纤维增强混凝土研究进展

随着我国“双碳”战略的持续推进,绿色低碳环保的天然纤维在水泥基材料中的应用已成为建筑行业的研究热点,得到了广泛关注。但植物纤维的力学性能差,同时存在老化和粘结力减弱等问题,很难直接应用于混凝土基体。本文综述了植物纤维的微观结构和性能,植物纤维对混凝土力学性能、耐久性和热物理性能等宏观性能的影响,植物纤维增强混凝土凝结时间、界面粘结和内养护的微观演变机制。讨论了植物纤维增强混凝土中基体改性和纤维改性的方法,深入了解不同方法的作用机理,寻求更加有效地改善性能的途径。剑麻纤维和竹纤维对混凝土性能有良好的提升作用,应用最为广泛。最后展望了植物纤维的可持续发展方向,为今后进一步研究植物纤维增强混凝土提出参考建议。     

Physical,mechanical, and water absorption behavior of coir/glass fiber reinforced epoxy based hybrid composites

Fiber reinforced polymer composites has been used in a variety of application because of their many advantages such as relatively low cost of production, easy to fabricate, and superior strength compare to neat polymer resins. Reinforcement in polymer is either synthetic or natural. Synthetic fiber such as glass, carbon, etc. has high specific strength but their fields of application are limited due to higher cost of production. Recently there is an increase interest in natural composites which are made by reinforcement of natural fiber. In this connection, an investigation has been carried out to make better utilization of coconut coir fiber for making value added products. The objective of the present research work is to study the physical, mechanical, and water absorption behavior of coir/glass fiber reinforced epoxy based hybrid composites. The effect of fiber loading and length on mechanical properties like tensile strength, flexural strength, and hardness of composites is studied. The experimental results reveal that the maximum strength properties is observed for the composite with 10 wt% fiber loading at 15 mm length. The maximum flexural strength of 63 MPa is observed for composites with 10 wt% fiber loading at 15 mm fiber length. Similarly, the maximum hardness value of 21.3 Hv is obtained for composites with 10 wt% fiber loading at 20 mm fiber length. Also, the surface morphology of fractured surfaces after tensile testing is examined using scanning electron microscope (SEM). POLYM. COMPOS., 35:925–930, 2014. © 2013 Society of Plastics Engineers     

Research and application prospect of short carbon fiber reinforced ceramic composites

With the advantage of high temperature resistance, low expansion, low density and excellent thermal stability, carbon fiber reinforced ceramic composites have a very wide range of applications in aerospace, military, energy, chemical industries and transportation. Short carbon fiber reinforced ceramic composites are characterized by simple processes, low manufacturing costs, short preparation times and automated production, can be used in fields such as friction materials and thermal protection system. This paper reviews the current status and recent advances in research on homogenization techniques, mechanical properties, thermal properties and frictional properties of short carbon fiber reinforce ceramic composites. Different processing routes for short carbon fiber reinforced ceramic composites, including reactive melt infiltration (RMI), hot pressing (HP), spark plasma sintering (SPS) and pressureless sintering, the advantages and drawbacks of each method are briefly discussed. The future development direction of low-cost manufacturing short carbon fiber reinforced ceramic composites is prospected.     

Statistical analysis of the mechanical properties of natural fibers and their composite materials. II. Composite materials

In this study, the tensile behavior of different natural fiber reinforced composite materials were analyzed. The statistical analysis used to study the natural fibers in the first article, has been extended to analyze the behavior of PP‐matrix composites, combining the probability density function estimation of fiber properties with the Halpin‐Tsai equation. In this case, the advanced statistical approach overestimates the mechanical properties of the composites, probably because of the poor matrix‐fiber adhesion between polypropylene and natural fibers in the real system. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

玻璃纤维增强聚丙烯复合材料耐水解性能的研究

以玻璃纤维增强聚丙烯复合材料为研究对象,选取两种玻璃纤维、不同相容剂及不同含量探讨玻璃纤维增强聚丙烯复合材料的性能,研究了在95℃水煮24 h前后的力学性能、微观结构和结晶变化。结果表明,添加聚丙烯专用耐水解玻璃纤维,在相容剂含量为3%时,可以大大提高聚丙烯材料的力学性能和耐水解性能,已经被应用于洗衣机滚筒等长期水接触的部件。     

Synthesis,chemical resistance,and water absorption of bamboo fiber reinforced epoxy composites

Natural fiber reinforced polymer composites are being increasingly used in the civil infrastructure. They have tremendous applicability to bridge systems ranging from use in seismic retrofit and strengthening of existing structural components, either in all composite form, or in conjunction with conventional construction materials. Natural fibers are not only strong and lightweight but also relatively inexpensive. Among the various natural fibers, bamboo finds widespread use in housing construction around the world, and is considered as a promising housing material. In this article, bamboo fiber reinforced epoxy composite has been synthesized by hand lay up technique. Effect of fiber content on chemical resistance and water absorption of composites has been studied to find the industrial suitability of the composites. Scanning electron micrographs of composites were used for a qualitative evaluation of the interfacial properties of bamboo/epoxy composites. These results indicate that bamboo can be used as a potential reinforcing material for making low load bearing thermoplastic composites. POLYM. COMPOS., 141–145, 2016. © 2014 Society of Plastics Engineers     

高性能热塑性树脂基复合材料的研究进展

近些年来,纤维增强热塑性树脂基复合材料已逐步发展成为复合材料中一个高性能、低成本的新型材料家族。本文主要介绍了各种高性能工程塑料和增强纤维的发展,连续纤维增强热塑性树脂的浸渍工艺及成型工艺,最后还介绍了热塑性纤维复合材料的发展趋势。     

先进复合材料用高性能纤维发展概述

作为材料科学的一个重要分支,纤维增强复合材料以其优异的性能取得了飞速发展并且在社会各领域得到了越来越广泛的应用。在先进复合材料中,目前最常应用的高性能增强纤维有碳纤维、芳香族聚酰胺纤维以及超高分子量聚乙烯纤维等。本文即对这些纤维的发展及其在先进复合材料中的应用情况作一概述。     

Behavior of sisal fiber concrete cylinders externally wrapped with jute FRP

The use of environmentally friendly natural fibers as building materials is benefit to achieve a sustainable construction. This article performs a study on the use of natural jute fibers as reinforcement of concrete and natural sisal fibers in fiber reinforced polymer (FRP) composites as concrete confinement, i.e., sisal fiber reinforced concrete (SFRC) composite column wrapped by jute FRP (JFRP) (SFRC‐JFRP). Uniaxial compression test was conducted to assess the compression performance of the composite columns as axial structural member. A total of 24 specimens were tested. The effects of JFRP wrapping thickness and sisal fiber inclusion on the compressive performance of the composite columns were investigated. Results indicate that JFRP confinement significantly increases the compressive strength and ductility of both PC and SFRC with an increase in JFRP thickness. Besides, the inclusion of sisal fiber further enhances the strength as well as the efficiency of confinement under uniaxial compression. Also, the models for ultimate strength and ultimate strain of PC‐JFRP and SFRC‐JFRP are proposed. POLYM. COMPOS., 38:1910–1917, 2017. © 2015 Society of Plastics Engineers     

长纤维增强热塑性复合材料的研究进展

本文论述了热塑性树脂基复合材料的发展特点。除介绍了最具发展潜力的长纤维增强热塑性复合材料的浸渍工艺和成型工艺外，还着重介绍了新型长纤维增强热塑性复合材料和其应用前景。     

麻纤维增强聚合物复合材料的研究进展

简要介绍了麻纤维的表面改性方法,概括了麻纤维/热固性树脂和麻纤维/热塑性树脂复合材料的研究进展;介绍了麻纤维/聚合物复合材料的加工工艺,展望了麻纤维增强复合材料的发展前景。