Bio-based thermosetting resins from waste cooking oil

In recent years, the research on sustainable and bio-based polymers and their applications has gained considerable attention due to socio-economic factors and environmental concerns. Vegetable oils are renewable, abundant and low-cost resources to obtain sustainable polymers with different structures, properties and applications as they offer an opportunity to tap into a pool of complex molecules in terms of carbon skeleton, double-bonds and functionalities availability. Our group has recently developed a strategy where acrylated-epoxidized monomers obtained from vegetable oils have been used with bio-based comonomers such as terpenes to afford thermosetting resins with comparable properties with respect to the ones obtained from comonomers of fossil origin (i.e. styrene). In the context of renewable bio-based materials, waste cooking oil (WCO) is a promising alternative to virgin vegetable oils since it is far cheaper and has a greater impact on the waste valorization and sustainability principles. In this work, WCO was used as starting material for the preparation of acrylated monomers and their combination with terpenes (limonene and β-myrcene) as comonomer for the preparation of various thermosetting resins. The acrylated resins were obtained following a three-step process: (1) epoxidation of double bonds of WCO, (2) acrylation of epoxidized WCO and (3) curing in the presence of comonomer and radical initiator. Moreover, experiments on the use of epoxidized WCO to obtain non-acrylic thermosetting resins in combination with different dicarboxylic acids such as fumaric, tartaric, succinic, adipic and azelaic acid and monocarboxylic acids such as oleic and sorbic were carried out. The thermal and mechanical characterization of bio-based thermosetting resins proved that the proper choice of the starting modified oil and comonomer allows to obtain resins with tunable properties. This study was conducted within the MICS (Made in Italy—Circular and Sustainable) Extended Partnership and received funding from the European Union Next-Generation EU.