AbstractFive desyl aryl sulfides were prepared for use as photoinitiators in the determination of the bulk polymerization rates of tetraethylene glycol dimethacrylate at 25°C. As a first approximation, the initial rates were first‐order with respect to monomer and one half‐order with respect to initiator. From this, approximate initial overall rate constants were determined. The data indicate that resonance stabilization of the dissociated radical seem to affect the polymerization rate. Complications arising from the auto catalytic gel effect were discu