1. Textile Research Division National Research Centre 33 El Bohouth St PO 12622 Dokki Giza Egypt
2. Polymer Department National Research Centre 33 El Bohouth St PO 12622 Dokki Giza Egypt
3. German Institutes of Textile and Fiber Research (DITF) Körschtalstr. 26 Denkendorf 73770 Germany
4. Institute of Polymer Chemistry University of Stuttgart Pfaffenwaldring 55 Stuttgart D‐70569 Germany