Investigation of eco‐friendly chemical treatments of apple pomace for producing high quality molded pulp biocomposite

Abstract

AbstractEco‐friendly chemical treatments using citric acid (CA) and sodium bicarbonate were employed to remove pectin, hemicellulose, and extractives from apple pomace (AP) for improving AP fiber quality and maximizing its utilization in producing biocomposite boards with newspaper (NP) fibers (AP:NP ratio of 2:1) using molded pulp technique. CA treatment was further optimized at different pH and temperature and cellulose nanofiber (CNF, 0.15, 0.3% w/w pulp solids) was used as reinforcement agent to enhance mechanical property and water resistance of biocomposite boards. CA treatment improved AP fiber strength and cellulose content. AP treated by CA at pH 2.5 and 75°C with 0.15% CNF reinforcement produced AP/NP biocomposite board with high flexural strength, and dimension stability, and low density. Thermal analysis verified increased cellulose content, crystallinity, and thermal stability of CA treated AP fibers. This study provided new insight to improve fiber functionality and utilize AP for developing sustainable packaging.