The effect of gamma radiation on biodegradability of natural fiber/PP-HMSPP foams: A study of thermal stability and biodegradability

Abstract

This research was carried out to evaluate how gamma-radiation-affected polypropylene (PP)/ high-melt-strength polypropylene (HMSPP) structural foams reinforced with sugarcane bagasse (SCB), in terms of thermal properties, biodegradability, and infrared spectrum. Polymers are used in various applications and in different industrial areas providing enormous quantities of wastes in environment, contributing with 20-30% of the total volume of solid residues. Besides, shortage of plastics resins obtained from oil and natural gas is addressing research and development toward alternative materials; environmental concerning in litter reduction is being directed to renewable polymers for manufacturing of polymeric foams. Biodegradable polymers, a new generation of polymers produced from various natural resources, environmentally safe and friendly, can contribute for pollution reduction, at a low cost. High-density structural foams are specially used in civil construction, in replacement of metals, woods, and concrete, but contribute for environmental pollution, due to components nature. In this study, it was incorporated SCB in PP/HMSPP polymeric matrix blends. Gamma radiation applied at 50, 100, 150, 200, and 500 kGy doses showed effective for biodegradability induction. Thermogravimetric analyses pointed toward stability around 205 °C; decomposition of both cellulose and hemicellulose took place at 310 °C and above, whereas the degradation of reinforced fibers composites took place above 430 °C. Infrared spectrum of foams was studied using FTIR, showing no sensitivity to the presence of C = C and C = O functional groups.