Bacterial cellulose reinforced with skim/fresh natural rubber latex for improved mechanical, chemical and dielectric properties

Abstract

Bacterial cellulose (BC) was reinforced via immersion in diluted skim natural rubber (SNR) latex and fresh natural rubber (FNR) latex to improve the mechanical, chemical and dielectric properties. The effects of the SNR and FNR latex concentrations (1–5% dry rubber content, DRC) and immersion temperatures (50–60 °C) on the composite film characteristics were investigated. The resulting mechanical properties of the SNR-BC and FNR-BC films were significantly enhanced compared to the neat BC film. Smaller size particles in SNR latex could extensively diffuse into the BC network, resulting in a much higher loading of SNR into BC film, as compared to that of FNR. The composite BC film with the highest elongation at break at 28% was obtained by immersion in a 5% SNR latex suspension at 60 °C, whereas the film with the highest tensile strength at 177 MPa was obtained by immersion in a 5% FNR latex suspension at 50 °C. The reinforcement strongly improved the structural stability of the composite films in water, and the composite films showed good chemical resistance in toluene. The composite films were biodegradable and could be degraded by 50–100% within 4–6 weeks in soil. The dielectric properties, in terms of dielectric constant and dielectric loss, of the BC film modified by a 5% SNR latex loading at immersion temperature of 60 °C were considerably enhanced to 170 (at 102 Hz) and 76 (at 102 Hz), respectively. With the reinforced mechanical and dielectric properties, SNR-BC composites offer potential for further development in electronic applications. FNR-BC films might also be applied as low dielectric materials for microelectronics. Graphical abstract: [Figure not available: see fulltext.].