1. Department of Materials Science and Engineering, Iowa State University, , Ames, IA, USA;2. Department of Chemistry, Faculty of Science, Cairo University, , Orman‐Giza, Egypt;3. School of Mechanical and Materials Engineering, Washington State University, , Pullman, WA, USA
Abstract:
Novel biorenewable copolymer thermosets are successfully synthesized by the ring‐opening metathesis polymerization (ROMP) of norbornenyl‐functionalized castor oil (NCO) and norbornenyl‐functionalized castor oil alcohol (NCA) with controlled amounts of 0.8 and 1.8 norbornene rings per fatty acid chain, respectively. The NCO and NCA monomers are mixed in different concentrations and simultaneously polymerized via ROMP using Grubbs catalyst. Broadband dielectric relaxation spectroscopy (BDRS) is used to investigate the molecular dynamics of the fully cured copolymer thermosets over a wide range of frequencies (5 × 10?2 to 0.5 × 107 Hz) at different constant temperatures (?70 to 125 °C). Four phenomena, namely α‐, β‐, and γ‐relaxation processes and ionic conductivity are observed for all the measured samples.
