Polypropylene/glass fiber composites for low cost orthotic aid

Abstract

Orthotic aid is an externally applied device used to modify the structural and functional characteristics of the neuromuscular and skeletal system. The orthotic devices are fabricated using polymer resins such as HDPE, polypropylene, acrylics etc. of which polypropylene (PP) is the most widely accepted material for this application. However, the limitations associated with polypropylene devices are decreased durability because of material tears or splits. In the present work, silanized glass fibers (GF) of varied length were used to reinforce and improve the performance of PP for fabricating polypropylene-glass fiber (PP-GF) composites through melt blending process, which provides high performance orthotic aid material with dramatic improvement in properties such as strength, stiffness, dimensional stability etc. Maleic anhydride grafted PP (PP-g-MAH) was used as compatibilizer to improve the compatibility between PP and silanized GFs in the composite. The PP-GF composites were characterized with Scanning electron microscopy (SEM) and Fourier Transform Infra Red spectroscopy (FTIR). Mechanical properties of PP-GF composites was investigated as per ASTM standards. Mechanical studies claimed that the hardness, tensile properties, of PP-GF composites increases over PP-resin, while elongation at break and impact strength decreases. Compatibilized PP-GF composites reinforced with 10 wt% GFs with elongation at break ~50 % at room temperature, showed improved mechanical performance over PP resin, which makes them suitable material for developing orthotic aid. Thus, PP-GF composites will offer lighter, stronger orthotic devices at lower cost.