Bio-based epoxidized natural rubber/chitosan/cellulose nanocrystal composites for enhancing mechanical properties, self-healing behavior and triboelectric nanogenerator performance

A new biocomposite was prepared from epoxidized natural rubber (ENR) reinforced with chitosan (CHI) and cellulose nanocrystals (CNCs) without using conventional crosslinking agents. The existence of strong hydrogen bonds in the biocomposite induced a supramolecular network or crosslinks. In this study, CNCs were isolated from Napier grass stems and treated with amino-triethoxysilane, called A-CNCs, prior to being incorporated into the biocomposite at various contents. Mechanical properties, self-healing behavior, and triboelectric nanogenerator (TENG) performance of the ENR/CHI/A-CNC biocomposites were subsequently evaluated. The results showed that modulus and hardness increased continuously as A-CNC content increased, whereas tensile strength was found to be maximum at 1 phr of A-CNCs. Similarly, the self-healing efficiency was notably improved with increasing A-CNC content up to 2 phr. The impaired self-healing property at higher A-CNC content is attributed to the reduction in interdiffusion and poor filler dispersion. Self-healing efficiency was also enhanced with increasing healing time and temperature (up to 80 degrees C). The TENG performance was found to be maximum at 1 phr of A-CNCs with an output voltage and current of 107.7 V and 10.6 mu A, respectively. The highest power density of 156 mW/m(2) was obtained when an external load resistance of 9 M Omega was applied. Clearly, the biocomposites containing approximately 1-2 phr of A-CNCs possess the optimum combination of strength, self-healing, and TENG performance. [GRAPHICS] .

Automated summary

A new biocomposite was developed by reinforcing epoxidized natural rubber (ENR) with chitosan (CHI) and cellulose nanocrystals (CNCs) without conventional crosslinking agents. The addition of A-CNCs improved the strength, self-healing capability, and triboelectric nanogenerator (TENG) performance of the biocomposite. Optimal properties were observed when the A-CNC content was approximately 1-2 phr.