Synthesis and Characterization of Bio-based Hybrid Polyurethane Materials

Bio-based organic inorganic hybrid polyurethane was successfully developed by modifying the conventional actylic polyurethane with cardanol derived hybrid material. The synthesis of hybrid material involved formation of maleic anhydride adduct of cardanol in the first step followed by its hybridization with epoxy functional silane in second step. The molecular structure of synthesized hybrid precursor was characterized by spectroscopic analysis (H-1-NMR, C-13-NMR and Si-29-NMR). The synthesized precursor was further used as reactive polyol as a partial replacement to conventional acrylic polyol in the preparation of polyurethane at various concentrations (30 and 50 wt % of acrylic resin). The modified polyurethanes were evaluated for their performance in terms of mechanical, optical, thermal, chemical, and accelerated weathering properties. The experimental results revealed that the synthesized cardanol based hybrid chemistry could be used as modifier to conventional acrylic binder with enhanced performance. The performance of the modified material can be attributed to the increased content of siloxane moieties which forms more inter and intra molecular covalent bonding and thereby imparting excellent performance.