The penetration of epoxy resin into plant fibre cell walls increases the stiffness of plant fibre composites

Abstract

A treatment is described that enables epoxy resin to penetrate into the cell walls of plant fibres. This ensures a very good interface in the cured composites, mimicking the way that interfaces are formed in animal and plant materials. The treatment involves swelling the plant cell walls with urea solution, washing out the excess urea and then replacing the water with alcohol in a graded series. Epoxy resin can then penetrate into the swollen cell wall and mix with the alcohol. The alcohol is probably driven off during curing of the resin. This treatment increased the stiffness of composites made from flax fibres and epoxy resin.