1. Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa; Central Analytical Facility, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa; BASF Research, GKT/U−B1, D-67056 Ludwigshafen, Germany; and Lab of Polymer Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands