POLYPROPYLENE COMPOSITES REINFORCED WITH COMBINATIONS OF MICA AND FIBER II.INVESTIGATION ON INTERFACAIL PROPERTIES

Mica filled polypropylene based GMT (glass mat reinforced thermoplastic) has been prepared by a double belt press using mica filled polypropylene as matrix material and continuous glass mat as reinforcement. The effect of the addition of mica on the mechanical properties of the prepared GMT sheet was investigated. The results indicated that the addition of a small amount mica increased the strength and modulus remarkably, the combination of mica and continuous glass fiber exhibited positive reinforcing effect. However, with increasing mica content the strength and modulus decreased, the combination of mica and continuous glass fiber exhibit negative reinforcing effect. This result was attributed to the effect of the addition of mica on the fiber-matrix interfacial adhesion in the GMT composites. At lower mica content, the fiber-matrix interfacial adhesion was enhanced, however, at large mica content the interfacial adhesion was damaged. At higher mica content the fiber-matrix interfaial adhesion was effectively enhanced via using MPP. As a result the strength and modulus of the composites were significantly improved. In addition, the effect of mica particle size on the mechanical properties of the composites was also studied.