EFFECT OF SOLID-STATE MODIFIED POLYPROPYLENE ON THE PHYSICAL PERFORMANCE OF SAWDUST-FILLED POLYPROPYLENE COMPOSITES

The influence of solid-state modified polypropylene on the physical pe rformance of uncoated or thermoset-resin coated sawdust-filled polypro pylene composites was studied. The effect of composition of the compos ites on tensile strength, Young's modulus, tensile toughness, elongati on, and impact strength was determined through two 2(3) factorial rota table designs. The results of this investigation show that both the m- phenylene dismaleimide-modified polypropylene precompounded sawdust as well as solid-state modified maleated polypropylene can be successful ly used to prepare sawdust-filled polypropylene composites with good t ensile strength. On the whole, this property improved compared to that of unfilled polypropylene. According to the analysis of factorial des ign, the optimum composition to prepare a composite with highest tensi le strength within the experimental range was 30-40 wt% phenolic resin coated sawdust together with 4-6 wt% solid-state modified maleated po lypropylene; while the product composition for the worst design was a combination of high amount of phenolic resin modified polypropylene wi th phenolic resin coated sawdust. The experimental design also conclud ed that effect of compositions on impact strength of composites was no t significant in most of the cases. Overall, the empirical models cons tructed in this study provided a good approximation to actual experime ntal measurements; we are encouraged to extend this approach to proces sing conditions for manufacturing these composites.