Surface Interaction of Advanced Micro Filler-RHA on Tensile Performance of Its Composites with Polypropylene

Rice hull ash (RHA) is good filler in some polymers. Polypropylene (PP) is often mixed with filler to improve mechanical properties. However RHA/PP composites have poor properties. RHA is hydrophilic where as PP is hydrophobic. This paper reports on a study to improve the properties of RHA/PP composites by addition of surface treatment agent, Methacryloxypropyltrimethoxy (MPS) silane, with particular focus on the role of the filler/polymer interface. Addition of 20 wt% of RHA in PP increases the modulus by 67% and reduces the tensile strength by 15%. Addition of silane in the system shows insignificant effect on the tensile properties. RHA properties and its interaction with surface treatment agent is characterized using TGA and FTIR. Results derived from TGA and FTIR were very useful in determining the bonding mechanism of silanes to RHA surface.