Gradient porosity poly(dicyclopentadiene)

This article describes the preparation of gradient porosity thermoset polym ers. The technique used is based on polymerizing a solution of cross-linkab le dicyclopentadiene and 2-propanol. The forming polymer being insoluble in 2-propanol, phase separation occurs. Subsequent drying of the 2-propanol g ives porosities up to 80%. An apparatus was built to produce a gradient in 2-propanol concentration in a flask, resulting in polymerized gradient poro sity rods. The resulting materials have been characterized by scanning elec tron microscopy (SEM) and density measurements. A mathematical model which allows prediction of the gradient produced is also presented.