1. Laboratory of Polymer Chemistry, Eindhoven University of Technology, Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, Agrotechnology and Food Innovations, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands, and Dutch Polymer Institute, P.O. Box 902, 5600 AX Eindhoven, The Netherlands