Tailoring natural rubber composites via surface-modified nanocellulose whiskers with sodium isopropyl xanthate: characterization and performance analysis

The surface modification of nanocellulose whiskers is vital for improving the compatibility between hydrophilic nanocellulose whiskers (NCW) and hydrophobic natural rubber (NR). In this study, we surface-modified Acacia caesia-derived nanocellulose whiskers using an eco-friendly ball milling method with sodium isopropyl xanthate, a vulcanization accelerator. The resulting sodium isopropyl xanthate (SX)-modified nanocellulose whiskers were comprehensively characterized using various analyses. Incorporating 2 parts per hundred rubber (phr) of SX-modified NCW significantly enhanced tensile strength by 27% and tear strength by 57% compared to unfilled NR gum. Notably, the NR-NCW-SX-2 phr composite exhibited a 21% reduction in swelling index and a 10% decrease in nitrogen gas permeability relative to NR gum. Biodegradability increased with higher filler loadings. High-resolution TEM analysis revealed effective alignment of modified nanocellulose whiskers along rubber particle boundaries, forming a segregated network configuration. In summary, our study elucidates the impact of NCW-SX on NR latex, offering intriguing prospects for applications such as gloves, catheters, swim caps, and related products.