Greater concern for environmental safety and fuel economy has increased interest in the use of renewable resources for development of new materials. Wood-plastic composites, made of recycled plastic and wood wastes, are very attractive in this respect, making this one of the most dynamic areas of new developments in the plastics industry in the past decade. This paper presents the preparation and characterization of polypropylene-sawdust composites by compression molding using maleated polypropylene (MAPP) produced in Brazil by reactive extrusion, with different amounts of two types of peroxides. The MAPP was characterized for thermal properties, melt flow index, and chemical structure, while the composites containing both uncoated and MAPP-coated sawdust were characterized for mechanical properties to understand the effect of coating as well as to compare these properties with those of composites prepared with commercial MAPP. The MAPP was efficient as a compatabilizer for polypropylene/sawdust composites. Better impact and tensile properties were observed in composites prepared with medium and high melt flow index compatibilizer concentrations, respectively.

Considering the importance of the environment and fuel economy, the Brazilian automotive industry has focused on the development of lightweight materials based on renewable resources. Replacement of PPtalc composite by PP-saw dust composite is a promising possibility. This paper presents the preparation of maleated polypropylene (MAPP) through reactive extrusion using different amounts of peroxides and maleic anhydride as well its characterization. Using 20% of saw dust coated with different amounts of prepared MAPP, several composites were prepared including one with commercial MAPP. Injection molded samples of all these composites along with that without the compatibilizer were characterized for mechanical properties. These studies indicated fulfilling the proposed objectives: (i) finding the optimal reactive extrusion conditions to prepare MAPP samples; (ii) preparation of PP/saw dust composites with and without MAPP coating; (iii) to arrive at optimized composite to get the best performance through their characterization for various properties of all the produced composites.