Mechanical Properties and Morphology of PMMA Grafted Silica/PMMA Injection Molded Composites

摘要

Micro- and nano-scale silica particles filled poly (methyl methacrylate) (PMMA) composites were prepared using high shear compounding and thin-wall micromolding. Mechanical performances of the composites were elucidated through tensile tests and internal structures of fractured surfaces were obtained from microscopic observations. The incorporation of silica particle has raised the tensile modulus of all specimens irrespective of processing conditions. Distribution of micro-fillers in the molded specimens was preferential towards the end side than the gate and center sides. Nano-filler particles were dispersed uniformly in most parts of the specimen while boundary separations between filler and matrix could be observed at the skin layer in micro silica filled PMMA. This led to an assumption that there was better filler-matrix adhesion in nano-filler composites than in micro-filler composites.