A Selective Route for Synthesis of Linear Polydicyclopentadiene

The present work looks at results recently obtained in polymerization of dicyclopentadiene to linear polydicyclopentadiene (LPDCPD) using two families of highly active and selective tungsten-based catalytic systems. In a first approach LPDCPD was obtained from endo-DCPD in excellent yields using catalytic systems consisting of WCl6 or WOCl4 and organosilicon compounds. IR and 13C NMR microstructure investigations indicated a prevailingly cis double bond configuration. The linear polymer displayed quite low glass-transition temperature and good thermal and electrical properties, combined with appreciable solubility in various organic solvents. From solutions of the linear polymer, elastic and resistant films having superior adhesion on many solid surfaces (wood, metal, plastic materials) could be produced. Conversely, the catalytic system derived from tungsten tetraphenyl-porphyrinate and diisobutylaluminoxane led to linear polydicyclopentadiene with a predominantly trans configuration of the backbone double bonds. This latter system behaved in a “living” fashion opening access to polymers with monomodal and narrow molecular weight distribution. Applying the examined strategy in copolymerization of dicyclopentadiene with other cycloolefins (cyclopentene and cyclooctene) afforded new copolymers with incorporated LPDCPD blocks recommending them as potentially valuable materials.