Awareness of the environmental implications of conventional reinforcing fillers and the urge to reduce the carbon footprint have lead researchers to focus more on natural and sustainable materials. Nanocellulose from multitudinous sources finds use in elastomer engineering because of its distinctive properties, such as renewability, sustainability, abundance, biodegradability, high aspect ratio, excellent mechanical properties, and low cost. Green alternatives for conventional fillers in elastomer reinforcing have gained considerable interest to curb the risk of fillers from nonrenewable sources. The differences in properties of nanocellulose and elastomers render attractiveness in the search for synergistic properties resulting from their combination. This review addresses the isolation techniques for nanocellulose and challenges in its incorporation into the elastomer matrix. Surface modifications for solving incompatibility between filler and matrices are discussed. Processing of nanocomposites, various characterization techniques, mechanical behavior, and potential applications of nanocellulose elastomer composites are also discussed in detail.

Background: Packaging of locust beans is done to prevent deterioration and promote its shelf-life. This research was carried out to develop and evaluate a cocoyam starch-banana peels nanocomposite film for locust beans packaging. The film was prepared by gelatinizing a mixture of 0.36 g banana peels nanoparticles (~ 1.14–1.64 nm), 18 g cocoyam starch, and 18 ml glycerol in 300 ml distilled water at 90 °C. The thermal, structural, mechanical and barrier properties of the film were determined using standard procedures. A 100 g of the locust beans condiment was packaged using the film and compared with packaging in a low-density polyethylene (LDPE) at 5.16–7.58 pH and 16.67–11.50% moisture ranges. Results: Results indicate approx. 3% weight loss with an increase in temperature (≤ 250 °C). The heat of decomposition in the process was 4.64 J/g, which depended on the transition temperature. Also, the film has high stiffness and creep along the line of topography in the atomic force imaging. The material permeates more to CO₂ (27%) and H₂ (67%) but has a low O₂ (4%) and N₂ (1%) gas permeabilities. The size of particles in the film was in the range of 3.52–3.92 nm, which is distributed across its matrix to create the pores needed to balance the gases in the micro-atmosphere. The microbial load of the locust beans decreased with pH and increased with moisture, but this was generally lower compared to those packaged in the LDPE at p < 0.05. Conclusions: The film was a better packaging material than the LDPE since it recorded lower counts of the microbes throughout the storage. Thus, the nanocomposite film was effective in controlling the microbial growth of the locust beans irrespective of the sample moisture and pH over the 30 days packaging duration.