Non-isothermal curing kinetics of soybean oil-based resins: Effect of initiator and reactive diluent

Soybean oil has been utilized as a raw material to develop biobased polymer to replace petroleum-based counterparts due to its abundance, renewability, and molecular designability. Acrylated epoxidized soybean oil (AESO) is a commercially available product and has been used in coatings, plasticizers, and composites. The curing of AESO resins normally refers to the free-radical polymerization of C--C bonds, which is closely related to the types of initiators and reactive diluents (RDs). In this work, the processing parameters and curing kinetic mechanism of AESO resins were investigated based on the extrapolation method, Kissinger, Crane, and Friedman equations, and the influences of initiators and RDs on the curing of the resins were explored. Results indicated that the types of initiators significantly affected the processability and curing kinetics of AESO resins, and the curing temperatures and reaction activation energy of the resins were strongly associated with the decomposition temperature and activation energy of the initiators. The number of C--C bonds and molecular structure of RDs considerably influence the curing characteristics of the resins. The addition of RDs endowed the reaction more complexity, and the activation energy significantly depended on the level of C--C conversion.