Polymerization of acrylonitrile with <i>n</i>‐butyllithium at −78°C.

Abstract

Abstract The polymerization of acrylonitrile with n ‐butyllithium in toluene at −78°C. was studied at three monomer concentrations, 5.7, 13, and 27%, and at butyllithium concentrations from 0.5 to 1.5 × 10 −2 m./1. With high concentrations of monomer the conversion was reduced by a gel effect. At low monomer concentrations the dependence of polymerization rate on monomer and catalyst concentration was similar to the dependence observed by other workers in the polymerization of styrene with butyllithium at 20–30°C. At −78°C. in toluene there was no evidence for termination of polyacrylonitrile chains by monomer. Cyanoethylation and reactions which produce yellowing at higher temperatures were absent. The initial polymerization was rapid and the initial catalyst efficiency low. Molecular weights were from 250,000 to 1,300,000.