Search for: All records

ABSTRACT A trithiol‐triacrylate gel system for frontal polymerization was explored to establish the gelation time, shelf life, and frontal kinetics. The free‐standing gels were created by triethylamine‐catalyzed Michael addition of trimethylolpropane tris(3‐mercaptopropionate) to trimethylolpropane triacrylate such that sufficient acrylate functional groups were left unreacted to allow free‐radical frontal polymerization with the initiator 1,1‐bis(tert‐butylperoxy)‐3,3,5‐trimethylcyclohexane (Luperox 231). Systems with gelation times between 30 and 60 min that support frontal polymerization after up to 28 days of storage were achieved. The front velocity was found to depend on the 1,1‐bis(tert‐butylperoxy)‐3,3,5‐trimethylcyclohexane concentration. However, the amount of triethylamine, which was used to catalyze gel formation, did not significantly affect front velocity. The gel diameter and addition of milled carbon fiber (Zoltek px35) affected the front velocity. Cracks during frontal polymerization were reduced when Zoltek px35 was added to the formulation, which also increased the mechanical strength. Complex geometries of free‐standing gels were successfully polymerized. This system is potentially useful in situations where molding and reshaping gels are required prior to frontal polymerization, as well as enabling the ability to examine how mechanical forces like stretching and compression can affect front kinetics.