Studies of mechanical and thermal properties of polypropylene/LLDPE-copolymer blends and its glass fiber compositions

The mechanical properties, melting, and crystallization behavior of a series of blends of polypropylene (PP) with varying percentages of linear low density polyethylene (LLDPE) copolymer and different fraction of glass fibers were investigated. In mechanical properties tensile and flexural strength, tensile and flexural modulus tends to decrease with increasing percentage of LLDPE copolymer, while a tremendous increase is observed in elongation at break. However, addition of glass fiber results in an increase in both tensile, flexural strength and modulus, especially at 30% glass fiber, where a manifold increase is observed, thereby, reversing the trend of decrease in the tensile properties on incorporation of elastomer. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) data reveals the decrease in crystallinity and crystallite size distribution on increasing % of LLDPE copolymer and glass fiber in the unfilled and glass-fiber-filled blend.