MELT RHEOLOGICAL BEHAVIOR OF SHORT PINEAPPLE FIBER-REINFORCED LOW-DENSITY POLYETHYLENE COMPOSITES

The melt rheological behaviour of short pineapple fibre reinforced low density polyethylene composite has been studied using a capillary rhe ometer. The influence of fibre loading, fibre length, and fibre treatm ent on the rheology of composites was investigated. Studies were carri ed out in the temperature range of 125 to 145 degrees C and shear rate of 016.4 to 5468 s(-1). The melt viscosity was found to be increased with fibre loading. Various chemical treatments were made to improve f ibre-matrix interfacial adhesion. Treatments based on poly(methylene)- poly(phenyl)isocyanate (PMPPIC), silane and peroxide increased the vis cosity of the system due to high fibre-matrix interfacial interaction. Viscosity of the system decreased with increase of temperature. Howev er, in peroxide treated composites viscosity is increased due to the c rosslinking of composite at higher temperature. The fibre breakage dur ing extrusion was analysed using optical microscopy. The morphology of the extrudates has been studied by optical and scanning electron micr oscopies. Master curves were generated using modified viscosity and sh ear rate functions that contain melt flow index as a parameter. Copyri ght (C) 1996 Elsevier Science Ltd.