Mechanical Improvement of Ramie Woven Reinforced-Starch Based Biocomposite Using Biosizing Method

Abstract

Biocomposite materials have been developed that offer certain mechanical and environmental advantages and also renewable-abundant resources. Biocomposite are defined as composite materials that build up by natural cellulose fibers as reinforcement fibers and starch or biopolymer as natural matrix. Biocomposites also called as green composites. Based on previous paper (Marsyahyo et al, 2008), the density of ramie fibers is much less than that of synthetics fibers such as E-glass fibers but ramie fibers has surface characteristic to be applied as superior renforcement in composite material. The specific strength and specific modulus of natural fibres are comparable or even superior to E-glass fibres. Hence, there is an opportunity for using the natural fibres such as ramie) to replace the E-glass fibre for a composite reinforcement (Drzal et al. 2004). Drzal et al (2004) suggested that in order to develop biocomposites with better mechanical properties, it is necessary to solve the problems by suitable treatments to enhance the compatibility between fibers and the matrix. Natural fibers are inexpensive, abundant and renewable, lightweight, degradable and abrasive to processing equipments (Alvarez, Vazquez, & Bernal, 2006). According to Kalambur and Rizvi (2006), starch as biodegradable polimer to replace synthetic polymer has still needed to improve because of complex disadvanteges including brittleness in the absence of suitable plasticizers, hydrophilic nature of starch and poor water resistance, deterioration of mechanical properties upon exposure to environmental conditions like humidity, and soft and weak nature of starch in the presence of plasticizers. Starch as an inexpensive material and renewable source is biodegradable and biocompatible. Its small granule size makes it as good particulate filler in many polymer blending systems (Ning et al , 2010). Also starch has its stiffness, tensile strength, and gas permeability are comparable to those of synthetic polymers from fossil fuels as a matrix in composite. Torres et al (2007) reported that starch processing method was not so complicated compare to synthetic polymers and can be produced from a wide variety natural resources and also compatible to plasticizer to improve their properties. Because of their mechanical performances, natural fiber and natural starch, as a composite system, were used intensively for components subtitution in automotive and engineering structures