1. German Institutes of Textile and Fiber Research; Körschtalstr. 26 D-73770 Denkendorf Germany
2. Leibniz Institute of Polymer Research Dresden; Hohe Straße 6 D-01069 Dresden Germany
3. Chair of Macromolecular Compounds and Fiber Chemistry; Institute of Polymer Chemistry; University of Stuttgart; Pfaffenwaldring 55 D-70550 Stuttgart Germany