Physical Modification of Natural Fibers and Thermoplastic Films for Composites — A Review (original) (raw)
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Natural fiber suspensions in thermoplastic polymers. I. Analysis of fiber damage during processing
Journal of Applied Polymer Science, 2007
The final properties of the composites materials are strongly dependent on the residual aspect ratio, orientation, and distribution of the fibers, which are determined by the processing conditions. Present work is a systematic study of the influence of natural fiber concentration on its damage during all the steps involved in the composite compounding. The system under study is cellulose fiber-reinforced polypropylene. The fiber geometrical parameters—length, diameter, and aspect ratio—are measured, and their statistical distributions are assessed for different concentrations. It is found that the higher the fiber concentration, the lower the fiber damage. These results evidence a difference in behavior between the damage of flexible natural fiber and rigid ones. The results are analyzed in terms of fiber concentration regimes, fiber–fiber interaction, flexibility, and entanglements. Two competitive mechanisms of the fiber interaction are proposed for explaining the fiber damage behavior during the flow of the flexible natural fiber suspensions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2501–2506, 2007
Australian Journal of Basic and Applied Sciences, 2014
This research was carried out to evaluate how alkali treatment of selected natural fibres (kenaf, luffa, betel nut, banana and rice straw) influences thermal properties, morphological properties and infrared spectrum properties of the composites made from polypropylene reinforced with natural fibres. Composites were made by compression moulding technique using hydraulic hot press. Composites were characterized by thermo-gravimetric analysis (TGA) to establish their thermal stability. The infrared spectrum of both treated and untreated natural fibres/PP composites were studied using Fourier transforms infrared spectrometer (FTIR). Infrared spectroscopy is sensitive to the presence of chemical functional groups in the composites. A functional group is a structural fragment within a molecule. Scanning electron microscopy (SEM) was used to investigate the morphology of composites. Increase in the thermal stability and better fibre-matrix compatibility of the composites were noticed in the treated fibres. Thermal stability of all the reinforced natural fibres was found to be around 205oC. Decomposition of both cellulose and hemicellulose in the fibres took place at 310oC and above, whereas the degradation of reinforced fibre composites took place above 430oC. After the chemical treatment, the FTIR results showed the reduction of OH bonds for all natural fibre composites used in this study. Mercerization had successfully modified the structure of natural fibres and these modifications improved the thermal stability of the composites by promoting better fibre-matrix bonding.
Natural fiber heat treatment on composite material
THE 3RD FACULTY OF INDUSTRIAL TECHNOLOGY INTERNATIONAL CONGRESS 2021 INTERNATIONAL CONFERENCE: Enriching Engineering Science through Collaboration of Multidisciplinary Fields
Composite material is a mixture of two or more materials that can produce new materials. Composite materials are composed of a matrix and reinforcement, the reinforcement used in the composite can use natural fibers. Natural fibers, have relatively affordable prices and can be decomposed by the environment compared to synthetic fibers. The use of natural fibers as reinforcement in composites can help balance nature. The resulting composite material also has strength that can be used to make materials for the manufacture of vehicle components. Composite materials can be produced using an injection molding machine. To make composite materials using injection molding, it is necessary to pre-treat the natural fibers used as reinforcement. The treatment is heating the fiber to reduce the water content in the fiber. Fiber heating is carried out to see the effect of water loss on the composite material. Heating was carried out for 5 hours using 5 temperature differences. The result shows that heating at 210 °C reduces the moisture content by 0.2258% and is the ideal temperature for heating natural fibers. The results of the composite material by heating the fiber at this temperature produce the best strength.
A Review on Natural Fibre-Based Composites—Part II
Journal of Natural Fibers, 2005
Natural abundance, much higher strength per unit weight than most inorganic fillers, lower density and their biodegradable nature make natural fillers attractive as reinforcements of engineering polymer systems. However, certain drawbacks such as incompatibility with the hydrophobic polymer matrix, the tendency to form aggregates during processing and poor resistance to moisture greatly reduce the potential of natural fibres to be used as reinforcements in polymers. In this review, the main results presented in literature are summarized, focusing on the processing behaviour and final properties of natural fibres with polymeric matrices (thermoplastics, thermosets and biodegradables) and paying attention to the use of physical and chemical treatments for the improvement of fibre-matrix interaction and composite mechanicaln properties. This work mainly focuses on the use of natural fibres for automotive applications.
A brief review on natural fiber used as a replacement of synthetic fiber in polymer composites
Materials Engineering Research, 2019
The use of composites in different sectors has become inevitable due to the enhancement in properties, reduction in the manufacturing cost and suitability to several applications. Among different classifications, polymeric composites are mainly focused on their use as structural components and the selection and composition of reinforcement play a vital role in determining the characteristics of the composite. Although composites are developed with man-made reinforcement in the beginning stage, in the present situation, natural reinforcements have proved excellent results in terms of properties. Hence, nowadays researches are mainly focused on the use of different natural fibers in different forms as reinforcements in polymeric composite. This work presents a brief overview on the properties of natural fiber and natural fiber reinforced composites which is an emerging area in polymer science. Interests in natural fiber is reasonable due to the advantages of these materials compared to others, such as synthetic fiber composites, including low environmental impact and low cost and support their potential to be used. Moreover, the disadvantage of the synthetic and fiberglass as reinforcement, the use of natural fiber reinforced composite gained the attention of the young scientists, researchers, and engineers and are being exploited as a replacement for the conventional fiber such as glass, aramid, carbon etc. Natural fibers have been proven alternative to synthetic fiber in transportation such as automobiles, railway coaches and aerospace, military, building, packaging, consumer products and construction industries for ceiling paneling, partition boards etc. However, in development of these composites, some drawbacks have also emerged. In this paper, it has been tried to overview all of this together.
A Review on Natural Fiber Reinforced Polymer Composite and Its Applications
Layth Mohammed, 2015
Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs) and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.
Chemical Treatments of Natural Fiber for Use in Natural Fiber-Reinforced Composites: A Review
Journal of Polymers and The Environment, 2007
Studies on the use of natural fibers as replacement to man-made fiber in fiber-reinforced composites have increased and opened up further industrial possibilities. Natural fibers have the advantages of low density, low cost, and biodegradability. However, the main disadvantages of natural fibers in composites are the poor compatibility between fiber and matrix and the relative high moisture sorption. Therefore, chemical treatments are considered in modifying the fiber surface properties. In this paper, the different chemical modifications on natural fibers for use in natural fiber-reinforced composites are reviewed. Chemical treatments including alkali, silane, acetylation, benzoylation, acrylation, maleated coupling agents, isocyanates, permanganate and others are discussed. The chemical treatment of fiber aimed at improving the adhesion between the fiber surface and the polymer matrix may not only modify the fiber surface but also increase fiber strength. Water absorption of composites is reduced and their mechanical properties are improved.
Effect of surface treatment on Natural fibers composite
IOP Conference Series: Materials Science and Engineering, 2018
The replacement of the synthetic fibers composite to natural fibers composites has become a key research area in the production industries. The advantage of natural fibers over a man-made fibers is low density, low cost, recyclability and biodegradability. But the natural fibers has a high level of absorption, this leads to poor wettability and insufficient adhesion within the matrix (internal adhesion) resulting degradation of composite properties. These properties hinder the potential of Natural fibers in providing successful reinforcement for polymer composites. In order to increase the potential of the Natural fibre Composites surface treatment is essential. In this paper various surface treatments and limitations are discussed, also the effects of surface treatment on the fibers are narrated. These properties will provide the base for further research in developing the Natural fibers composite without any degradation in its Characteristics.
Treatments of Natural Fibre as Reinforcement in Polymer Composites-Short Review
Functional Composites and Structures
The demand for environmental awareness, preserving nature and being beneficial for societal economics has attracted the attention of many researchers and industries to examine the potential usage of natural fibers. There are a lot of beneficial natural fiber sources in a wide range of applications in the composites industry. It is worth mentioning that the performance of natural fiber-reinforced composites can be tailored through a certain natural fiber treatment, and hybridization by employing an appropriate number of synthetic fibers or with other natural fibers. In addition to cost-effectiveness balance, a balance between environmental impacts and desired performance can be achieved by designing the composite based on the product requirements. Yet, certain drawbacks such as incompatibility with the hydrophobic polymer matrix, hydrophilic nature and the tendency to absorb moisture during processing greatly reduce the potential of natural fibers to be used as reinforcements in polymer composites. In this short review, the main results presented in the literature are summarized, focusing on the properties and challenges of natural fibers, the processing behavior of natural fiber treatments, and paying attention to the use of physical and chemical treatments for the improvement of fiber-matrix interaction as reinforcement for polymeric matrices (thermoplastics, thermosets and biodegradables). Hemicellulose Cellulose Lignin Therrmal degradation Hemicellulose Non crystalline celulose Crystalline cellulose Lignin Biological degradation Figure 1. Factors contributing to the diverse properties of natural fiber. This leads to lightweight composites being made. The demand for the commercial use of natural fiber-based composites in various industries, such as automobiles, aerospace and civil, has been increasing, as many reports have been released [4, 5]. The current usage of the word 'biodegradable' for natural fiber composites does in fact mean the use of natural fuels in the polymer sector and, as a result of the reduced operation of plastic burning, reduces reliance on oil supplies and emissions of greenhouse gases [6-8]. The definition 'natural fiber' includes all fiber forms present in plants (cellulose fibers), animals (protein fibers) and minerals that exist in nature (asbestos, chitin and chitosan). Flexible materials with a broad aspect ratio and high tensile strength can also be known as natural fibers. While fibrous materials are abundant, including cotton, wood, grain and straw in particular being cellulosic, not all materials are available for use in textiles or other industrial fibers. Apart from the economic viewpoint, the qualities of weight, softness, elasticity, abrasion resistance and surface characteristics drive the adequacy of a fiber for business purposes [9, 10]. The physical and mechanical properties of certain natural fibers, such as fiber structures, cellulose composition, the intrinsic angle and degree of polymerization, are dictated by their chemical and physical composition [11-13]. Swelling of the fibers because of the moisture accumulation is the major disadvantage of natural fibers, creating poor linkage to the composite fiber matrix [14, 15]. Natural fibers are inherently less mechanical than synthetic fibers. A key drawback in the production of high-performance materials is their low mechanical properties. Several mechanical approaches were found, including changes in interfacial attachment, physical handling, chemical composition and natural fiber-synthetic fiber hybridization. Hybridizing natural fibers, in order to overcome the drawbacks of the other kind of fibers, leads to the synergistic effect of hybridized fibers. The use of all fibers to build a hybrid fiber-reinforced composite structure provides a feasible balance between higher material properties and the environmental advantages of natural fibers. The effective arrangement of structural numbers also enhances the material properties of the hybrids. The use of reinforcing hybrid fibers has been found to be a practical alternative to standard synthetic construction materials for structural applications [16, 17]. In this way, a proper composite material design will balance costs, efficiency and sustainability. Figure 1 shows the factors contributing to the performance of biocomposites originated from natural fibers.