Effective elongation properties of cellulose–natural rubber composite hydrogels having interconnected domain

This report describes progress in the development of cellulose hydrogel by blending with natural rubber (NR). Cellulose regenerated from the bagasse sugarcane was used for this study. Although cellulose and NR have a considerably low mutual affinity, composite hydrogels with various cellulose and NR contents were prepared using a wet-phase inversion method. The maximum amount of NR that can be loaded into the cellulose hydrogel was about 30% vol. Once NR is introduced into the cellulose hydrogels, the obtained hydrogel became translucent and eventually opaque with increasing NR loading. Measurements of water absorption, the water contact angle, and evaluation of fourier-transform infrared spectroscopoy (FTIR) spectra revealed that the presence of NR decreases the water affinity of the hydrogels. Nevertheless, it is noteworthy that the composite hydrogels had higher tensile strength and better elastic properties than the pristine hydrogel. The results showed that the obtained composite hydrogels can be elongated several times to their original length. The enhancement of both properties was proportional to the amount of NR included. Results of scanning electron microscope (SEM) images showed NR present inside the hollow of the cellulose hydrogel, forming interconnected domains. One can infer that the increase of mechanical and elastic properties is attributable to the presence of these interconnected structures.