Mechanical performance and biodegradability of polyvinyl alcohol nanocomposite films

Abstract

AbstractThis study investigated the mechanical properties and biodegradability of polyvinyl alcohol (PVA) composite films. 3 wt.%, 5 wt.%, and 10 wt.% microcrystalline cellulose (MCC), commercial grade cellulose nanocrystals (NCCA), and nanocellulose (NCCB) extracted from oil palm fiber (OPF) were incorporated into polyvinyl alcohol by solvent casting. Field emission scanning electron microscopy (FESEM) images indicated that the average particle size of microcrystalline cellulose, commercial grade cellulose nanocrystals, and nanocellulose extracted from oil palm fiber are 12.63 μm±5.71 μm, 502.92 nm±196.10 nm, and 79.20 nm±11.69 nm, respectively. Nanofillers dispersed uniformly in polyvinyl alcohol matrix. Addition of microcrystalline cellulose up to 5 wt.% was able to improve the ultimate tensile strength (UTS) and yield strength of polyvinyl alcohol composite films but sacrificed the maximum elongation. Incorporation of 5 wt.% nanocellulose extracted from oil palm fiber is able to increase ultimate tensile strength, yield strength, and elastic modulus while maintaining the maximum elongation of polyvinyl alcohol composite films. Incorporation of commercial grade cellulose nanocrystals (up to 10 wt.%) increases ultimate tensile strength, yield strength, and maximum elongation while maintaining elastic modulus of polyvinyl alcohol composite films. Soil burial test result found that presence of moisture accelerated the degradation of the polyvinyl alcohol composite films drastically; the films were fully dissolved in the soil after 7 days. However, the weight of polyvinyl alcohol composite films did not change significantly after 28 days under controlled condition. This indicated that soil moisture is an important catalyst in biodegradation activity of polyvinyl alcohol composite films. Comparison with a commercially available biodegradable plastic bag (Bio‐PB) shows that the polyvinyl alcohol composite films developed in this study have superior mechanical performance and biodegradability, with potential to replace existing plastic bags.