Response Surface Methodology-A Useful Tool for the Optimization of Molecular Adhesion and Mechanical Properties of PP Composites

Abstract

Response surface design has been used to optimize the concentration of adhesion promoter in wood fiber-filled polypropylene composite in relation to maximiza tion of mechanical properties and thermal stability of modified composites. The method has also been used to find an empirical correlation between product composition and inter molecular bonding that has taken place due to the reactivity of itaconic anhydride modified polypropylene in the composite system studied. The adequency of the correlation is fur ther justified by FTIR and DSC results. The heat of fusion data of polypropylene in com posite which was used as a relative measure of change in degree of crystallinity in polypro pylene matrix, fairly explains the observed effects of response variables on degree of chemical bonding and mechanical properties. The controlled variables selected in design ing the experiment, however, suggests that a further study is needed in the higher concen tration range of wood fiber and modifier to optimize the cost and performance of product. Results in this study also revealed that a ridge analysis should be performed to find an unique extreme in the experimental region which will show the direction to proceed to find the optimum in further experimentation. Overall, this study demonstrated that response surface methodology could be used to find a quantitative correlation between composite composition and mechano-chemical properties.