1. Laboratory of Polymer Chemistry, Laboratories of Polymer Technology and Materials and Interface Chemistry, and Process Development Group, Technical University of Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, Department of Polymer Science and Structural Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, and Dutch Polymer Institute, P.O. Box 902, 5600 AX Eindhoven, The Netherlands