HYBRID COMPOSITE MATERIAL BASED ON POLYPROPYLENE REINFORCED WITH SILICON CARBIDE WHISKERS AND FUNCTIONALIZED FIBERGLASS

摘要

The invention relates to a process for preparing a hybrid composite material to be used in manufacturing motor-car products or consumer goods. According to the invention, the process consists in homogenizing, in a double-screw co-rotating granulating extruder, 77...89 parts of polypropylene homopolymer or copolymer, with 1...3 parts of polypropylene grafted with maleic anhydride, 3...10 parts of silicon carbide, previously dried fibres of 10 μ m in length and 1.5 μ m in diameter and 3...10 parts of fibres of borosilicate glass functionalized with 5 parts of dichloro-dimethylsilane, the parts being expressed by weight, per 100 g fibres, in 9 operation zones of 135-139-159-190-173-159-154-150-145°C, at a screw rotation speed of 50...100 rpm and a melt pressure of 50...60 bar, followed by extruding the mixture through a die in the shape of a rope, cooling it, drying it with hot air and granulating it, to result in a composite having a hardness of 62...85° ShD, breaking resistance of 19...70 N/mm, Young modulus 1.6...4.7 GPa and thermal stability under mechanical load of 67...180°C.