The Thermo-Mechanical Properties of Corn Cob Lignin-Containing Cellulose Nanofibril Reinforced Bioplastics

Abstract

Corn cobs fibers mainly the cellulose nanofibril (CNF) have been widely utilized as a reinforcement filler in bioplastic matrix. However, the preparation of CNF involves bleaching process which is not environmentally friendly. For that, lignin-containing cellulose nanofibril (LCNF) from corn cobs were prepared and its potential as reinforcement filler in bioplastic matrix was investigated. The LCNF were prepared by using soda process and silane treatment (3-aminopropyltriethoxysilane, APS) was performed for surface modification purpose. Specifically, the effects of LCNF loading and APS-treated LCNF loading (8 wt%, 10 wt% and 12 wt%) on the thermo-mechanical properties of corn starch-based plain bioplastic were evaluated. The results showed that a 12 wt% LCNF reinforced bioplastic has improved the tensile strength by 108% and reduced the elongation by 10% as compared to corn starch-based plain bioplastic. 12 wt% LCNF reinforced bioplastic was able to retain 9% more residues than the plain bioplastic at 300 , suggesting that the addition of LCNF improved the thermal stability of starch-based plain bioplastic. Interestingly, silane-treated LCNF reinforced bioplastic only showed minor improvements on mechanical strength at low LCNF loading (8 wt% and 10 wt%); When higher LCNF loading was introduced, the mechanical strength was found to be lower as compared to untreated LCNF reinforced bioplastic. Moreover, the effects of silane treatment on the thermal properties of LCNF reinforced bioplastic were insignificant in our study. This finding suggests that LCNF shows good potential as reinforcement filler in bioplastic matrix and silane treatment did not promote strengthening effects in this work.

Physical, Mechanical and Antibacterial Properties of Biodegradable Bioplastics from Polylactic Acid and Corncob Fibers with Added Nano Titanium Dioxide

“…Dried and ground corncobs possess high total dietary fiber content and have been reported to exhibit relatively high water holding capacity and high oil absorption ability [22]. Lignincontaining cellulose nanofibril from corncobs has been reported to exert good potential as reinforcement filler in bioplastic matrix [23]. This paragraph was set for the explanation "why the corncob fiber was used in this research".…”