A comparative analysis of physico-mechanical and aging properties of non-apparel grade coarse wool–natural rubber flexible composites

The study reports the preparation and characterisation of non-apparel grade wool–natural rubber (NR) composites. Non apparel textile grade wool obtained from Malpura sheep (highly coarse) and Chokla sheep (medium coarse) were converted in to hand woven fabric in a conventional handloom. Both the fabrics were milled, scoured and coated with different natural rubber latex concentrations through padding method. The latex-coated wool fabrics were then vulcanised at higher temperature and pressure to prepare wool–NR composites. The physical and mechanical properties of the developed wool fabrics and wool–NR composites such as fibre loading, tensile strength, elongation, Young's modulus, tear strength, porosity, hardness, abrasion resistance, moisture content, static and dynamic frication and water diffusion were analysed. The composites were further characterised with Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The aging properties of composites due to accelerated thermal, UV exposure and soil degradation was also performed. Upon comparing the physico-mechanical properties, it is observed that the DRC (Dry Rubber Content) was found to be the governing factor in determining the mechanical properties of the composites. While coating with same natural rubber latex concentration, the mechanical properties of the medium coarse wool–NR composite was found to be higher as compared to the highly coarse wool–NR composite. Prolonged exposure to high temperature and UV radiation caused a significant reduction in mechanical properties of the composites. Upon accelerated soil burial for 120 days, the pristine wool fabric was found to be fully decomposed meanwhile, the composites with high rubber content exhibited less degradation.