Polypropylene, constitutes the most attractive matrix for commodity products in the automotive industry and other industrial sectors such as electrical appliances. Good adhesion with glass fibers is currently obtained by modifying the polypropylene matrix with polar chemical coupling agents, altering significantly the cost (10% increase) of the final composite products. Thus, there is a strong need of the automotive industry for low cost polypropylene based composites having higher mechanical performances.
The best results have been obtained with systems incorporating coupling agents both on the glass fiber and into the PP matrix. The ambitious first objective of GLASSPROP (cost reduction of 20%) can not be reached because the uncoupled composites (no coupling agent in the matrix) obtained with the new coupling agent (emulsified PP) achieved lower mechanical properties than the actual glass fiber / PP composite and as a result the expensive coupling agent in the matrix can not entirely be suppressed.
Nevertheless, the progresses in the understanding of the phenomena governing the reinforcement of PP composites will allow all partners to pursue the research in the field of PP compounds in order to improve cost/performance ratio