Phosphinimide-ligated half-titanocene dichloride for the synthesis of polynorbornenes with controlled molecular weights and widely tunable thermal and mechanical properties

Abstract

A phosphinimide-ligated half-titanocene dichloride precatalyst enables coordination-insertion polymerization of norbornenes, affording soluble polymers with predictable molecular weights. This system also affords copolymers of norbornene with 5-tetradecyl-2-norbornene, where the combination of rigid backbones and long C14 alkyl side chains overcomes the inherent trade-off between enhanced glass transition temperature and mechanical toughness.