Reinforcement of tapioca/glucomannan/poly(lactic acid) biothermoplastic composite using cellulose derivatives

Abstract

This research aims to determine the cellulose-derived filler that produces the best characteristics of  the tapioca/glucomannan/polylactic acid (TP/GM/PLA) biothermoplastic composite. This research tried 10 treatments: control, use of microfibril cellulose (MFC), nanocrystalline cellulose (NCC), and nanofibril cellulose (NFC) with concentrations of 1.5, 2.5, and 3.5%, respectively. Measurements/observations: mechanical, physical, chemical, biodegradation, and thermal properties. The results showed that the TP/GM/PLA biothermoplastic composite with 2.5% NCC produced the best characteristics, with a tensile strength value of 24,668 MPa, elongation at break of 3.123%, Young's modulus of 1.843 GPA, and WVTR of 81.22 g/m².day, O₂TR of 85.46 ml/m².day, WHC of 0.17%, swelling of 2.92%, glass transition temperature of 60.98 ^oC, crystallinity temperature of 68.19 ^oC, melting point of 159.76 ^oC, melt flow rate of 8.55 g/min, density of 1.25 g/cm³, biodegradation time of 11.67 days. Furthermore, a 12% weight loss occurred up to 600 °C, with the highest DTA peak at 493.9°C with a value of 28 µV, and a crystallinity peak at a 2Ɵ angle of 29.51°C. This composite contains O-H (alcohol), C=O, C=C (aromatic ring), and C-O functional groups. The longitudinal surface profile contains small, densely packed spots with no obvious holes. The transverse surface profile shows all holes closed, compact, and dense.