Studies on epoxy and modified epoxy particulate composites

Abstract

Epoxies have a number of advantages like lack of volatiles evolution during cure and hence low shrinkage. This in turn leads to better adhesion to various substrates like metals and fibres. Epoxy resins can be cured over a wide range of temperatures and hence cross link density can be controlled. This leads to control the rigidity, toughness etc to the required levels. Hence they find a variety of applications in the areas of adhesives, composites, insulators, castings, foams and semi-conductor encapsulations. The most studied polymer is carboxyl terminated acrylonitrile butadiene copolymer (CTBN). The present work studies the possibility of developing a epoxy based material which may be used as a material for mould i.e., material for making Rapid tool. For this objective initially various combinations of aluminium powder, solid glass spheres and Amine containing Silicone (ACS) with epoxy was made and mechanical studies were carried out on those combinations. The results shows aluminium powder was found to improve compressive and flexural modulii and thermal conductivity of the resin. From the mechanical analysis based results, few combinations were identified as better and further studies were carried out on those specimens. In the machinability (surface finish and resultant tool force) studies, ACS addition was found to reduce the surface roughness after machining and also reduced the tool force, which leads to better machinability. Simulation studies were carried out by ANSYS software based on the results obtained for optimum proportion from the mechanical properties analysis. Finally an actual mould was made by the composition with optimum proportion and it is tested for suitability as mould in hand operated injection moulding machine. Over all, the studies indicate that epoxies can be modified by aluminium, solid glass spheres and ACS for making temporary moulds for limited number of runs. This can help in reducing the lead time for developing plastic products. newline newline newline