ROLE OF SILANE AND NOVEL WATER-BASED HYBRID COUPLING AGENTS IN INCREASING THE ADHESION BETWEEN NATURAL FIBER AND POLYPROPYLENE

摘要

After decades of high-tech developments of artificial fibers like aramid, carbon and glass it is remarkable that natural fibers have gained renewed interest, as glass fiber substitute in automotive and building product industries. The usual extrusion and subsequent injection molding processing techniques most widely accepted for natural fiber thermoplastic composites today, need an alternative environmentally benign powder impregnation method, as the fibers are damaged during the conventional processing techniques. Since natural fibers are polar and polypropylene is non-polar, suitable surface treatment is needed to improve fiber-matrix adhesion so as to obtain superior strength composites. Water-based surface treatment is a realistic way to achieve bio-composite of commercial value. Maleated polypropylene (MAPP) showed improved adhesion over silane treated bio-fiber to PP matrix. However the hybrid-coupling agent from the mixture of amino-silane and MAPP emulsion exhibited synergism in adhesion of bio-fiber to the PP matrix. Optimization of hybrid water-based coupling agent to get best fiber-matrix adhesion is in progress. The present investigations are limited to 40 wt.% fibers content and further increase of fiber content with optimum hybrid sizing is expected to result in much improved strength bio-composites.