Effect of plasticizer and carboxyl methyl cellulose (CMC) on degradable plastics from rice straw and palm fiber

This study used rice straw-based and palm fiber-based degradable plastics with glycerol and sorbitol. The strength of rice straw cellulose-based degradable plastics using 20% glycerol ranged from 2 to 5.75 MPa. Similarly, the strength of palm fiber cellulose-based degradable plastics using 40% sorbitol ranged from 5 to 11.13 MPa. In a chemical analysis, the peaks between 3444.87 cm-1 and 3651.25 cm-1 represented the O–H stretching of the alcohol group. This is shown by the C–O–H hydroxyl group at the wave numbers of 1627.92, 1724.36, and 1745.58 cm-1. Moreover, these groups are hydrophilic, binding water, so they can be degraded by microbial activity in the soil. In the thermal analysis, degradable plastics from rice straw lost a lot of weight between 431.53 and 520.79 ℃. Plastics derived from palm fibers as green products also showed extreme weight loss between 334.28 and 482.20 ℃. Most of the material was decomposed at 600 ℃. Both types of samples lost a lot of hydrogen groups and started to decompose and depolymerize. Rice straw plastic absorbed 10.73%–20.23% of water, while palm fiber plastic absorbed 15.34%–85.01%. The lowest water absorption rates were observed in rice straw and palm fiber degradable plastics. Rice straw and palm fiber cellulose plastics broke down in 45–48 days, in line with the American Standard Testing and Materials (ASTM) D-20.96 standard, which says that degradable plastic should take no more than 180 days to break down.