1. Laboratory of Polymer Technology, Department of Chemical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands, Dutch Polymer Institute, P.O. Box 902, 5600AX Eindhoven, The Netherlands, ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, United Kingdom, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany, and IPTME, Loughborough University, Loughborough, LE11 3TU, United Kingdom