Rui Ding and Michael Kessler
Iowa State University
Polymers derived from biorenewable resources are finding an increase in global demand. This work aims to develop a range of castor oil-based thermosetting polymers using ring-opening metathesis polymerization (ROMP). The effect of cross-linking agents on cure behavior and thermo-mechanical properties of the resins were studied to investigate and optimize the process conditions and properties. Specifically, a novel norbornyl-functionalized castor oil alcohol (NCA) was investigated to polymerize with two different cross-linking agents using ROMP. Isothermal differential scanning calorimetry (DSC) was used to investigate the conversion-time relationship during cure. Dynamic DSC scans at multiple heating rates revealed conversion-dependent activation energy by Ozawa-Flynn-Wall analysis. The glass transition temperature, storage modulus, and loss modulus for NCA copolymers with different amounts of cross- linking agents were compared using dynamic mechanical analysis. Mechanical stress-strain curves were developed through tensile tests, and thermal stability of the cross-linked polymers was evaluated by thermogravimetric analysis to further investigate the structure-property relationships in these systems.