Development of rice bran-based bioplastics via injection molding: Influence of particle size and glycerol ratio

Abstract

Plastics play a vital role in modern society but their non-biodegradable nature has led to environmental concerns. Biomass-derived biodegradable bioplastics offer an eco-friendly alternative and protein and starch-based bioplastics, sourced from agro-food residues, are gaining prominence due to their renewability. However, many bio-based materials face challenges and developing efficient processing methods is crucial for their industrial viability. Optimizing particle size and plasticizer proportion is vital to tailor the properties of bioplastics. This study evaluates rice bran-based bioplastics, produced via injection molding, considering particle size and the impact of glycerol ratio. Smaller particle sizes enhance interactions during processing and, the conditions achieved during mixing determined the relevance of biopolymer–plasticizer and biopolymer–biopolymer interactions, leading to different behaviors depending on their balance. The processability and final properties of the materials developed were also affected by the glycerol ratio, with higher rice bran proportion leading to better rheological and mechanical properties.