Preparation and Characterization of Natural Rubber/Chitosan Films

Abstract

Natural rubber/chitosan (NR/CS) films at various NR/CS ratios were prepared here from the mixture of natural rubber latex (NRL) and chitosan solution using a solution casting method. The NRLs with and without sulfur curing agents were used. The NR/CS films were obtained after heating at 50oC for 24 hours. The NR/CS films prepared from the NRL with curing agents were further heated at 120oC for 30 min to acquire the NR networks. From swelling testing, it was found that incorporation of CS into the NR matrix gave the films with higher solvent resistance. The swelling index reduced proportionally with the increased CS loadings. Additionally, the solvent resistance of the NR/CS films was improved more once the NR was cured. In general, for every NR/CS ratio, the tensile strengths of the cured NR/CS films were higher than those of the uncured NR/CS films. After thermal aging, it was found that the tensile strength of the uncured NR/CS films decreased while that of the cured ones increased. Two thermal decomposition peaks were observed. The onset decompostion temperatures at lower and higher temperature were corresponding to the degradation of chitosan and natural rubber, respectively. The initial thermal degradation temperature of CS and NR in the NR/CS films was shifted to the higher temperature than that of the pure CS and NR, respectively.