Development of biodegradable biocomposite films from poly(lactic acid), natural rubber and rice straw

This work aims to develop sustainable and biodegradable biocomposite films from renewable and environmentally friendly materials including poly(lactic acid) (PLA), natural rubber (NR), and rice straw (RS). The cast film extrusion method was used to produce all the films in the current work. The PLA/NR blend with 30 percent by weight (wt%) of NR, which showed the highest elongation at break of 372.10%, was selected for compounding with RS powder. The amounts of RS used in PLA/NR/RS biocomposite preparation were varied from 3 to 10 wt% of the total weight of the blend. The tensile properties of the film were decreased by the incorporation of RS fiber. However, ductile fracture behavior could still be observed if the RS content did not exceed 5 wt%. The biodegradability of all films was determined by measuring the percent weight loss of the films after soil burial. With an increase in RS amount, the degradation of the films was faster. The scanning electron microscopy (SEM) analysis showed that all PLA/NR/RS bicomposite films had a lot of cracks and holes on their surfaces. Gel permeation chromatography (GPC) showed that the molecular weight of PLA in all films went down after they were buried in soil. Also, the biocomposite films in this study demonstrate the potential to be used in agricultural products like planting bags.

Automated summary

This study aims to develop sustainable and biodegradable biocomposite films using renewable and environmentally friendly materials. Different films containing poly(lactic acid), natural rubber, and rice straw were produced using the cast film extrusion method. The addition of rice straw fiber decreased the tensile properties of the films, but ductile fracture behavior was still observed with appropriate amounts. The degradation of the films increased with higher amounts of rice straw. The biocomposite films also showed potential for use in agricultural products like planting bags.