Review of natural fibre-reinforced hybrid composites

Natural fibre-reinforced hybrid composites which contain one or more types of natural reinforcement are gaining increasing research interest. This paper presents a review of natural fibre-reinforced hybrid composites. Both thermoplastic and thermoset composites reinforced by hybrid/synthetic fibres or hybrid/hybrid fibres are reviewed. The properties of natural fibres, the properties and processing of composites are summarised

Influence of Short Glass Fiber Addition on the Mechanical Properties of Sisal Reinforced Low Density Polyethylene Composites

This paper presents the evaluation of enhancement in the mechanical properties of short sisal fiber reinforced polyethylene composites by the incorporation of short glass fiber as an intimate mix with sisal. Intimately mixed short glass-sisal hybrid fiber reinforced polyethylene composites (GSRP) were prepared by solution mixing technique. The effects of fiber orientation and alkali treatment on sisal fiber in GSRP were studied. Addition of relatively small volume fraction of glass (0.03) to the sisal reinforced polyethylene matrix (SRP) enhances the tensile strength of longitudinally oriented composites by about 80%. Addition of the same volume fraction of glass to the alkali treated sisal incorporated SRP enhances the tensile strength by more than 90%. The flexural strength of the longitudinally oriented composites was also studied. The incorporation of glass fiber ( V f = 0.03) to SRP enhances the flexural strength by more than 60%. The effect of hybridization on water absorption tendency of the sisal fiber was studied by immersing SRP and GSRP in boiling water for 3 hours. It was observed that water uptake of GSRP was 2 to 4 times less than that of SRP composites. Halpin-Tsai equation for composites was tried for calculating the tensile modulus of longitudinally oriented GSRP. </jats:p

Effect of fibre length and chemical modifications on the tensile properties of intimately mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites

Abstract: Hybrid composites prepared by the incorporation of two or more different types of fibres into a single polymer matrix deserve much attention. This method of hybridisation of composites offers a profitable procedure for the fabrication of products while the resulting materials are noted for their high specific strength, modulus and thermal stability. The influence of the relative composition of short sisal/glass fibres, their length and distribution on the tensile properties of short sisal/glass intimatelymixed polyethylene composites (SGRP) was examined. Different compositions of sisal and glass such as 70/30, 50/50 and 30/70 have been prepared with varying fibre lengths in the range of 1–10mm. Emphasis has also been given to the variation of fibre–matrix adhesion with several fibre chemical modifications. Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane and peroxides given to the fibres and matrix were found to be successful in improving the interfacial adhesion and compatibility between the fibre and matrix. The nature and extent of chemicalmodifications were analysed by infrared spectroscopy while improvement in fibre–matrix adhesion was checked by studying the fractography of composite samples using a scanning electron microscope. Assessment of water retention values has been found to be a successful tool to characterize the surface of the stearic acid modified fibres. It was found that the extent of improvement in tensile properties of SGRP varied with respect to the nature of chemical modifications between fibre and matrix. Improved mechanical anchoring and physical and chemical bonding between fibre and polyethylene matrix are supposed to be the reasons for superior tensile strength and Young’s modulus in treated composites. Several secondary reasons such as high degree of fibre dispersion and reduced hydrophilicity in chemically modified fibres also are believed to play a role. Among the various chemical modifications, the best tensile strength and modulus was exhibited by the SGRP with benzoyl peroxide treated fibres. This is attributed to the peroxide-initiated grafting of polyethylene on to the fibres. 2004 Society of Chemical Industr