The polymerisation of styrene by solid catalysts derived from the reaction of titanium IV compounds with grignard reagents

Solid catalysts, prepared by treating alkyl or aryl magnesium halides with titanium tetrachloride or butyl o‐titanate, polymerize styrene rapidly to amorphous low molecular weight (104–105) polymer. The energy of activation for the process is approximately 20 kcal/mole for all active catalysts. Kinetic evidence indicates that initiation and propagation proceed by insertion of monomer molecules at a metal‐carbon bond and that termination is spontaneous. If the catalysts are pre‐heated to 150°C., the polymer produced contains a substantial proportion of high molecular weight (ca. 5·106) crystalline material.