Study of Thermal Behaviour of Poly(Lactic) Acid Composites with Gamma Irradiated Luffa Fiber

Abstract

Modification of surface of natural fibers by high-energy gamma irradiation (6 MV) is a competent process for enhancing the adhesion between fiber and matrix. Composites reinforced with natural fiber have gained a prominent place in the field of research and innovation due to the advantages such as low cost, lightweight and environment friendly. We have studied the thermal properties of biodegradable composites using biodegradable polymer poly(lactic) acid and fiber of Luffa cylindrica (LC) fabricated by using injection molding technique. Before reinforcement LC fibers are irradiated with gamma rays of 0.5, 1 and 2 Gy using 6 MV linear accelerator at room temperature in the presence of air. The thermal properties like glass transition temperature (Tg), crystallization temperature (Tcc), melting peak temperature (Tm) and thermal stability of the composites are studied using differential scanning calorimetry in the temperature range from 30 to 250 °C and thermogravimetric analysis in temperature range from 20 to 700 °C. The variation of these properties in response to the irradiation dose and fiber loading is analyzed in detail. It is observed that with increase in irradiation dose, glass transition temperature and crystallization temperature are increasing. However, the thermal stability of the composites is found to decrease with increase in irradiation dose.