Enhancing cure characteristics, mechanical properties and swelling resistance of chloroprene rubber/natural rubber composites with halloysite nanotubes

This study investigates the enhancement of the mechanical and physical properties of a 50/50 chloroprene rubber (CR) and natural rubber (NR) blend by incorporating halloysite nanotubes (HNTs) as a nanofiller. HNTs, a member of the nanoclay family, were added in varying concentrations up to 10 parts per hundred rubber (phr). Cure properties, including torques and cure times, were measured and analysed to understand the effects of HNT incorporation. The innovative aspect of this work lies in the exploration of HNTs’ potential to enhance mechanical properties such as tensile strength, hardness, tear strength and elongation at break, as well as swelling resistance across different solvent environments. The swelling resistance was quantified through mole percent solvent uptake in aromatic, aliphatic and chlorinated solvents, revealing the influence of HNT loading and penetrant size. The study also employed field-emission scanning electron microscopy to examine the morphology of fractured composites. The findings demonstrated that the mechanical properties and swelling resistance of the CR/NR blend improved with increasing HNTs loading, with optimal enhancements observed at 6 phr of HNTs. This work offers valuable insights into the use of HNTs as a reinforcing agent for rubber blends, providing a pathway for developing materials with improved performance across multiple properties.