METATHESIS POLYMERIZATION OF NORMAL-PHENYLNORBORNENEDICARBOXIMIDE

This paper describes the ring-opening metathesis polymerization (ROMP) of N-phenylnorbornenedicarboximide (NDI). The exo isomer of NDI is found to polymerize into a high molecular weight straight-chain polymer with high conversion. Under similar conditions, the polymerization of the endo isomer leads to a low molecular weight polymer with low conversion. In the polymerization of isomer mixtures the molecular weight and molecular weight distribution and the total conversion decrease with an increase in the endo concentration in the monomer feed; the maximum amount of endo isomer incorporated in the polymer chain is found to be about 28%. The glass transition temperatures of polymers produced using ruthenium and osmium catalysts, having predominantly a trans structure of the double bond, are about 15-degrees-C higher than the polymers produced using tungsten catalysts, having a mixture of cis and trans double bonds. Copolymerization of NDI with 5-norbornene-2-carbonitrile (NN) produces random copolymers; the glass transition temperature increases linearly with an increase in the imide content in the copolymer.