Natural Rubber Films Reinforced with Cellulose and Chitosan Prepared by Latex Aqueous Microdispersion

In this paper, green composite films comprising natural rubber (NR), cellulose (CE), and chitosan (CS) were successfully fabricated through a simple, facile, cost-effective method in order to improve mechanical, chemical, and antimicrobial properties of NR composite films. Chitosan with a low molecular weight of 30,000-50,000 g/mol (CS-L) and a medium molecular weight of 300,000-500,000 g/mol (CS-M) was used for the fabrication. The composite films were prepared via a latex aqueous microdispersion method with different weight ratios of NR:CE:CS-L/CS-M. Fourier transform infrared spectroscopy (FTIR) results demonstrated strong interactions of hydrogen bonds between CE and CS-L/CS-M in the composite films. The tensile strength and the modulus of the composite films in dried form were found to significantly increase with the reinforcement of CE and CS-L/CS-M. The maximum tensile strength (13.8 MPa) and Young's modulus (12.7 MPa) were obtained from the composite films reinforced with CE at 10 wt.% and CS-L at 10 wt.%. The high elongation of 500-526% was obtained from the composite films reinforced with CE at 10 wt.% and CS (CS-L or CS-M) at 5.0 wt.%. The modification could also significantly promote antimicrobial activities and chemical resistance against non-polar solvents in the composite films. The NR composite films have potential uses as flexible films for sustainable green packaging.