What is "autoacceleration"

n. (context organic chemistry English) A local increase in the rate of polymerization of a viscous monomer

Autoacceleration (Gel Effect, Trommsdorff-Norrish Effect) is a dangerous reaction behavior that can occur in free radical polymerization systems. It is due to the localized increases in viscosity of the polymerizing system that slow termination reactions. The removal of reaction obstacles therefore causes a rapid increase in the overall rate of reaction, leading to possible reaction runaway and altering the characteristics of the polymers produced.