A new hybrid waterborne polyurethane coating synthesized from natural rubber and rubber seed oil with grafted acrylate

A new hybrid waterborne polyurethane (WPU) was successfully synthesized by emulsion polymerization from hydroxyl telechelic natural rubber (HTNR) and hydroxylated rubber seed oil (HRSO) at 50:50 M ratio as the polyol with grafted acrylate. The morphology of WPU was characterized by TEM, and its chemical structure was confirmed by FT-IR spectroscopy. The WPU had a good stability with total solids content of about 16 % and gave good film formation. The polarity and mechanical properties were improved by grafting BA/MMA co-monomer onto the WPU. The effects of the BA/MMA proportion were investigated. The new hybrid WPU-g-P(BA/MMA) demonstrated good dispersion and the particle size slightly increased with proportion of BA/MMA. The mechanical properties of the hybrid WPU-g-P(BA/MMA) films were studied from their stress-strain curves. The surface wetting and adhesive strength tended to increase with the proportion of BA/MMA in grafting. The results demonstrate a new way to utilize renewable resources in the form of a novel hybrid polyurethane, supporting the concept of eco-friendly materials in green coating applications.