Control of Biodegradability Under Composting Conditions and Physical Performance of Poly (Lactic Acid) Based Materials Modified with Phenolic-Free Rosin Resin

Abstract

Biodegradable materials based on poly (lactic acid) (PLA) and a phenolic free modified rosin resin were obtained and studied to control the biodegradability under composting conditions of the materials. The resin was blended in concentrations of 1, 3, 5, 10, and 15 parts per hundred (phr) of base polymer using industrial plastic processing techniques. Additionally, to study the effect of the resin on the compatibility of the PLA, the physical performance, water absorption, mechanical behavior, thermal stability, and microstructure of the materials were assessed. The resin incorporation decreased the resistance to thermal degradation of the resultant material, and the composting disintegration rate was slowed down with the increasing content of the resin. The water diffusion was delayed, and the diffusion and corrected diffusion coefficients decreased with the rising content of UP. The mechanical properties tend to decrease while a saturation effect was observed for contents higher than 3 phr of resin. The optimal amount of resin that can be added to achieve good interaction with PLA matrix, complete miscibility, and good material cohesion is 3 phr.