Effect of chain structure on the properties of Glass fibre/polyethylene composites

Abstract

Three types of polyethylenes (low density: LDPE, medium density: MDPE, and high density: HDPE) were used to investigate the effect of chain branching on the dispersion and adhesion in Glass fibre reinforced polymer composites. The interaction between the polyethylene matrix and the Glass fibres was investigated in terms of differences in mechanical behaviour, morphological characteristics, rheological and thermal properties between the three polymer composites systems. Addition of Glass fibres enhanced the mechanical properties for all systems. The degree of enhancement, however, depended on the branching and crystallinity of each polymer. The long chain branching (LCB) in LDPE resulted in higher increases both in the Elastic (Young’s) modulus in the solid state and in the Storage modulus in the melt. The higher crystallinity of HDPE was responsible for higher increase in tensile strength and less fibre pull-out upon addition of Glass fibres. Rheological results also confirm the same observation for LCB. The addition of Glass fibres also resulted in improved thermal stability of the various polyethylene samples.