Experimental investigation of micro-hardness behaviour of dual blended reinforced polymer matrix composites of five selected fortifiers

Ajibade O.A. ; Agunsoye J.O. ; Oke S.A. (2018)

Staff publications


The abounding views on composite’s damage potential evaluations restricts composite’s life-cycle computations and associated decision making to metal-rooted composites due to the dearth of literature contributions on agro-rooted hardness evaluations of polymer composites. In recent times, nevertheless, appreciation has expanded that particulate forms of selected agro-rooted reinforced polymer composites such as orange peels, periwinkle shells, palm kernel shells, egg shell and coconut shells are as well substantial drivers of micro-hardness information for the life-cycle cost computations of automotive parts replacements due to their cassinogenic influences (i.e. brake pads). Rooted on experimental arguments, overwhelming facts are provide in a new way concerning the hardness values of some hitherto unexplored dual blends of reinforced agro-based composites mentioned earlier. Hardness tests was carried out on epoxy composites based on the dual reinforcement mixtures of (OPp/CSp), (PKSp/CSp), (PSp/ESp), (OPp/PSp) and (PKSp/ESp) in polymer composites of volume fractions. The composites were post-cured under three different temperatures, 80, 100 and 120oC. For the 80oC post-cured composites. The (15PKSp/10CSp) and (20PKSp/5CSp)% composites (formulation 2) had the highest hardness of 29.3 HV under all the post-cured conditions. A second aspect of the work is to explore an investigation on the relationship between the hardness, tensile, impact and flexural strength properties of five dual particle filled epoxy composites. The different relationships for each composite were represented by mathematical models with the hardness fitted as the response variable while the remaining properties were adjusted as the predictor variables at six levels of observations using the multiple regression analysis. A confidence interval of 95 % and p-value of < 0.05 were used in the build up to the models and each model showed good significance and high correlation (R2) values with the (PKSp/ESp) model obtaining the highest R2of 0.972. The models helped to understand which of the predictor variables was most relevant to the hardness response variable of the composite which will help to make informed decisions on practical usage. The compelling results therefore influence the current research landscape and perceptions on micro-hardness determinations in an effort for more effective damage potential evaluations of polymer composites.