PERFORMANCE OF SURFACE MODIFIED NUTSHELL FLOUR IN HDPE COMPOSITES

The nutshells of different mesh sizes, e.g. 100, 200 and 325, were modified by polymer grafting with maleic anhydride [MA] (1-3% by weight of filler), dicumyl peroxide [DPO] (1% by weight of filler) and high density polyethylene [HDPE] (5%“by weight of filler). The mechanical properties of both compression molded and injection molded composites containing HDPE and modified or unmodified nutshell have been investigated. The mechanical properties of modified nutshell-filled composite materials are generally higher than those of unmodified ones. Moreover, both strength and modulus of modified nutshell-filled composites improve even compared to those of unfilled polymer: The maximum improvements in mechanical properties, except those of modulus which increases continuously with the addition of more and more fillers to the composites, occur between 20% and 30% filler content, but in a few cases they occur even at 40%. Moreover, 3% MA seems best as far as the concentration of MA is concerned and properties improve more when 200 mesh nutshells are used as a filler compared to those of mesh sizes 100 and 325. The impact strength of the composites is inferior to that of the original polymer. Experimental results as well as cost analysis indicate that surface modified nutshells are a potential reinforcing filler for thermoplastic composites. © 1992, Taylor & Francis Group, LLC. All rights reserved.