Suspension Polymerization of Thermally Expandable Microspheres Using Cinnamonitrile and Diethyl Fumarate as Crosslinking Agents

Abstract

Thermally expandable microspheres (TEMs) were synthesized via suspension polymerization using acrylonitrile as the major monomer. Methyl methacrylate and methacrylonitrile were used as supporting co‐monomers, and 1,4‐butanediol dimethacrylate was used as a crosslinking agent. In addition, cinnamonitrile (CN) and diethyl fumarate (DEF) were investigated as monomers to improve the expansion performance of the TEMs. However, the expandability of the TEMs using CN was diminished. When TEMs were prepared with DEF as the crosslinking agent, the expandability was highly affected. From the thermomechanical analysis of TEMs with various crosslinking agents, DEF showed better performance as crosslinking agent, yielding increased expansion properties. This is the first report using DEF as a TEM crosslinking agent.