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.

Chemical Treatments of Natural Fiber for Use in Natural Fiber-Reinforced Composites: A Review

Natural fiber reinforced composites is an emerging area in polymer science. These natural fibers are low cost fibers with low density and high specific properties. These are biodegradable and non-abrasive. The natural fiber composites offer specific properties comparable to those of conventional fiber composites. However, in development of these composites, the incompatibility of the fibers and poor resistance to moisture often reduce the potential of natural fibers and these draw backs become critical issue. This review presents the reported work on natural fiber reinforced composites with special reference to the type of fibers, matrix polymers, treatment of fibers and fiber-matrix interface. © 1999 John Wiley & Sons, Inc. Adv in Polymer Techn 18: 351–363, 1999

Natural fiber polymer composites: A review

Recently, there has been a rapid growth in research and innovation in the natural fibre composite (NFC) area. Interest is warranted due to the advantages of these materials compared to others, such as synthetic fibre composites, including low environmental impact and low cost and support their potential across a wide range of applications. Much effort has gone into increasing their mechanical performance to extend the capabilities and applications of this group of materials. This review aims to provide an overview of the factors that affect the mechanical performance of NFCs and details achievements made with them.

A review of recent developments in natural fibre composites and their mechanical performance

Natural fiber reinforced polymer composites (NFPCs) provide the customers with more alternatives in the material market due to their unique advantages. Poor fiber–matrix interfacial adhesion may, however, negatively affect the physical and mechanical properties of the resulting composites due to the surface incompatibility between hydrophilic natural fibers and non-polar polymers (thermoplastics and thermosets). A variety of silanes (mostly trialkoxysilanes) have been applied as coupling agents in the NFPCs to promote interfacial adhesion and improve the properties of composites. This paper reviews the recent progress in using silane coupling agents for NFPCs, summarizes the effective silane structures from the silane family, clarifies the interaction mechanisms between natural fibers and polymer matrices, and presents the effects of silane treatments on the mechanical and outdoor performance of the resulting composites.

Silane coupling agents used for natural fiber/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

Pretreatments of Natural Fibers and their Application as Reinforcing Material in Polymer Composites—A Review

Pineapple leaf fiber (PALF) which is rich in cellulose, relatively inexpen- sive, and abundantly available has the potential for polymer reinforcement. The present study investigated the tensile, flexural, and impact behavior of PALF-reinforced polyes- ter composites as a function of fiber loading, fiber length, and fiber surface modification. The tensile strength and Young's modulus of the composites were found to increase with fiber content in accordance with the rule of mixtures. The elongation at break of the composites exhibits an increase by the introduction of fiber. The mechanical proper- ties are optimum at a fiber length of 30 mm. The flexural stiffness and flexural strength of the composites with a 30% fiber weight fraction are 2.76 GPa and 80.2 MPa, respec- tively. The specific flexural stiffness of the composite is about 2.3 times greater than that of neat polyester resin. The work of fracture (impact strength) of the composite with 30% fiber content was found to be 24 kJ m 02 . Significant improvement in the tensile strength was observed for composites with silane A172-treated fibers. Scanning electron microscopic studies were carried out to understand the fiber-matrix adhesion, fiber breakage, and failure topography. The PALF polyester composites possess superior mechanical properties compared to other cellulose-based natural fiber composites. q 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1739-1748, 1997

Mechanical properties of pineapple leaf fiber‐reinforced polyester composites

Effects of environment on the properties of low-density polyethylene composites reinforced with pineapple-leaf fibre

Melt rheological behaviour of short pineapple fibre reinforced low density polyethylene composites

Short pineapple-leaf-fiber- (PALF)-reinforced low-density polyethylene (LDPE) composites were prepared by melt-mixing and solution-mixing methods. In the melt-mixing technique, a mixing time of 6 min, rotor speed of 60 rpm, and mixing temperature of 130°C were found to be the optimum conditions. Tensile properties of melt-mixed and solution-mixed composites were compared. Solution-mixed composites showed better properties than melt-mixed composites. The influence of fiber length, fiber loading, and orientation on the mechanical properties has also been evaluated. Fiber breakage and damage during processing were analyzed from fiber distribution curve and optical and scanning electron micrographs. Considering the overall mechanical properties and processability characteristics, fiber length of 6 mm was found to be the optimum length of pineapple leaf fiber for the reinforcement in LDPE. The mechanical properties were found to be enhanced and elongation at break reduced with increasing fiber loading. Longitudinally oriented composites showed better properties than randomly and transversely oriented composites. Recyclability of the composite was found to be very good. A comparison of the properties of the PALF-reinforced LDPE composites with those of other cellulose-fiber-reinforced LDPE systems indicated superior performance of the PALF-LDPE composites. © 1995 John Wiley & Sons, Inc.

Short pineapple-leaf-fiber-reinforced low-density polyethylene composites

Nonisothermal crystallisation, melting behavior and wide angle X-ray scattering investigations on linear low density polyethylene (LLDPE)/ethylene vinyl acetate (EVA) blends: effects of compatibilisation and dynamic crosslinking

S. S. Bhagawan

Papers

Mechanical properties of pineapple leaf fiber‐reinforced polyester composites

Effects of environment on the properties of low-density polyethylene composites reinforced with pineapple-leaf fibre

Melt rheological behaviour of short pineapple fibre reinforced low density polyethylene composites

Short pineapple-leaf-fiber-reinforced low-density polyethylene composites

Nonisothermal crystallisation, melting behavior and wide angle X-ray scattering investigations on linear low density polyethylene (LLDPE)/ethylene vinyl acetate (EVA) blends: effects of compatibilisation and dynamic crosslinking