Optimisation of waste vegetable oil-based thermoset polymers

Bio-based thermoset polymers were produced from epoxidised waste vegetable oils (WVOs) cured with anhydrides at different molar ratios. Properties were compared to analogues produced with neat oil and diglycidyl ether of bisphenol A as a feedstock. The thermal stability proved to be affected by the molar ratio, and the use of feedstock from waste oil resulted in no effect on this property. A dynamic mechanical analysis has shown that higher concentrations of anhydride enhance the storage modulus, glass transition temperature (up to 42·5°C) and cross-link density. The frying process proved to play a minor role in tuning the dynamic mechanical properties. However, the contribution of the anhydride was demonstrated to be significant enough to mitigate the losses caused by the waste oil, as shown statistically in a design of experiment study. All formulations were chemically resistant to aqueous, organic and acidic media. The identification of the effects of critical parameters on the properties of WVO-based thermosets enables the further production of polymers from waste streams.