Synthesis of vinyl-type functionalized polynorbornenes with cyclic pendant imide side groups by using palladium-based catalyst for low dielectric constant materials

A set of functionalized polynorbomenes with various substituted pendant imide groups (N-substituent imide group = adamantyl, cyclohexyl, tolyl, and phenyl) have been prepared via vinylic pathway by using di-mu-chloro-bis-(6-methoxybicyclo[2.2.1]-hept-2-ene-endo-5 sigma,2 pi)-palladium(II) catalyst as a means of developing materials for low dielectric constant. The effects of molar ratio of monomer to catalyst, solvent polarity, reaction time. and temperature on the polymerization of substituted norbornene-5,6-dicarboximide were investigated. Among the monomers used, exo-N-cyclohexyl-norbornene-5,6-dicarboximide recorded the highest activity, giving 90% conversion in 30 min. All the resulting functionalized polynorbornenes are characterized by good thermal properties (similar to 5% weight loss at 440 degrees C) and low dielectric constants (2.26-2.53), which are desirable for the next generation of microprocessors and memory for computers to provide insulation in the increasingly shrinking feature sizes of faster microprocessors. (C) 2008 Elsevier Ltd. All rights reserved.