Facts

DO YOU KNOW - The Bulk Polymerization with a free radical catalyst of Acrylonitrile  becomes explosively fast after 40% conversion

 Cause - This happen because of the Viscosity build-up and the resulting Trommsdorff effect. This effect is due to a Decrease in thr rate at which the polymer chain diffuse through the viscous medium. Therefore there is a Decrease in the termination reaction and this step become diffusion controlled. Therefore this Trommsdorff effect, also called gel effect or auto acceleration, exhibitsa marked deviation from first-order kinetics in the direction of higher molecular means of avoiding thos danger.

Solution - In industry, for example , acrylonitrile is not polymerized in Bulk but generally polymerized either by precipitation polymerization from water or in solution using DMF,DMAC, or DMSO as solvents. In addition , chain transfer agent may be added to the system to limit the molecular weight and therefore the viscosity build-up.

References - Billmeyer,F.W., Textbook of polymer science and Polymer Science Study Guide-Gerald S. Kirshenbaum