Sustainable strategy for the synthesis of novel vegetable oil derived polymeric materials

Abstract

This study reports a sustainable strategy to produce polymeric materials with convenient properties, employing principles close to green chemistry, starting from epoxy/methacrylate vegetable oil monomers. New bio-based derivatives were obtained from the well-known epoxidized linseed oil, reacted with a renewable reagent, undecylenic acid, using suitable synthesis parameters in heterogeneous catalysis. The undecylenic double bonds grafted on the linseed oil structure were then reacted, resulting epoxidized undecylenic acid-linseed oil (monomer 1). Monomer 1 was further used as an intermediate to obtain methacrylic derivatives: monomer 2—methacrylate epoxidized undecylenic acid-linseed oil (bearing both epoxy and methacrylic moieties) and monomer 3—methacrylate undecylenic acid-linseed oil (bearing only methacrylic functionalities). These three monomers were employed in different eco-friendly ultraviolet/visible light curing attempts, proving their ability to generate polymer networks in different reaction conditions. The resulting materials were investigated through different thermal and thermo-mechanical assays, establishing their general properties. The influence of the undecylenic fragments, epoxy/methacrylate content and curing conditions were established. Gel fraction varied according to the initial precursor composition (62/87% for the epoxy-based materials; 58/91% for the methacrylic-based materials). A good elasticity was observed for the new materials (Tg ranging from 20 to 44°C), and a great thermal resistance also (thermal degradation temperatures of 400/453°C for the epoxy network and 382°C for the methacrylic one), in good agreement with other studied mono- or di-functional polymer matrices.