Hydrothermal aging and soil biodegradation characteristics of biopolymer based sustainable composites

The current research endeavor examines the water absorption (in-service life) and soil biodegradation (end-of-the-service life) behavior of short sisal fiber (SF) reinforced poly (lactic acid) (PLA) and bio-based poly (butylene succinate) (bio PBS) composites. Samples were fabricated by extrusion-injection molding with varying sisal fiber loading of 10, 20, and 30 wt%. The water absorption test was conducted in distilled water at three distinct temperatures (5, 25, and 45 °C) for 336 h. The sorption behavior of composites was studied experimentally, and detailed diffusion kinetic behavior is discussed using Fickian diffusion models. The impact of fiber content and hydrothermal temperature on water diffusion and maximum water absorption was investigated in detail. A soil burial test was conducted in local farmland soil for 60 days to determine the influence of fiber content on the biodegradation characteristics of composites. After exposure to hydrothermal aging, it was concluded that fiber loading was most significant in affecting the maximum percentage of water absorption, whereas hydrothermal temperature was more relevant for higher water diffusion. Soil burial tests showed that SF/bioPBS composites degraded quickly as compared to PLA composites. Overall, composites made with bio PBS have shown an expected response than PLA composites in terms of water absorption and soil biodegradation.