1. Research Department, ICI Paints, Wexham Road, Slough SL2 5DS, United Kingdom
2. Chemistry Department, University of Southampton, Highfield, Southampton S09 5NH, United Kingdom
3. Consejo Superior de Investigaciones Científicas, Instituto de Ciencia y Technología de Polímeros, Calle Juan de la Cierva 3, 28006 Madrid, Spain