Morphology and Mechanical Properties of Normal Blends and In-Situ Microfibrillar Composites from Low-Density Polyethylene and Poly(ethylene terephthalate)

Abstract

In this work, normal blends, microfibrillar blends and composites were prepared from low density polyethylene (LDPE) and poly(ethylene terephthalate) (PET) in 85/15 and 75/25 w/w% ratio in the presence and absence of a compatibilizer polyethylene grafted with maleic anhydride (PE-g-MA). The microfibrillar composites (MFCs) were prepared using extrusion – drawing – isotropization technique. The morphology development of the microfibrillar blends and composites was studied using scanning electron microscopy (SEM). The presence of 5 wt% PE-g-MA compatibilizer affected the continuity of the fibrils differently in 75/25 and 85/15 w/w% microfibrillar blends. In the case of normal blends the addition of compatibiliser reduced the size of the dispersed PET phase. The presence of PET microfibrils improved the tensile properties of the microfibrillar composites. The normal blends exhibited a relatively ductile failure during tensile loading in comparison with the microfibrillar composites. The microfibrillar nature of the dispersed phase was found to improve the stiffness of the composite rather than their impact strength.

Keywords:

• Compatibilization
• Microfibrillar composites
• Morphology
• Tensile strength

ACKNOWLEDGMENT

The authors gratefully acknowledge M/s Futura Polymers Ltd., India for the kind supply of PET material, STIC – Kochi for SEM analysis, and Mr. Rajasundar for the illustrations.