The present invention relates to wood pulp and polyareneazole pulp for use as reinforcement material in products including for example friction materials, fluid sealing materials, and papers. The pulp comprises (a) irregularly shaped, wood pulp fibrous structures, (b) irregularly shaped, polyareneazole fibrous structures, and (c) water, whereby wood pulp fibrils and/or stalks are substantially entangled with polyareneazole fibrils and/or stalks. The invention further relates to processes for making such wood pulp and polyareneazole pulp.