title: Permanent flame retardant finishing of textiles by allyl-functionalized polyphosphazenes.
abstract: Despite their excellent flame retardant properties, polyphosphazenes are currently not used as flame retardant agents for textile finishing, because a permanent fixation on the substrate surface has failed so far. Here, we present the successful synthesis and characterization of a noncombustible and foam-forming polyphosphazene derivative, that can be immobilized durably on cotton and different cotton/polyester blended fabrics using photoinduced grafting reactions. The flame retardant properties are improved, a higher limiting oxygen index is found, and the modified textiles pass several standardized flammability tests. As flame retardant mechanism a synergistic effect between the immobilized polyphosphazene and the textile substrate was observed. The polyphosphazene finishing induces an earlier decomposition of the material with a reduced mass loss in thermogravimetric analysis. The decomposition of cotton and polyester leads to the formation of phosphorus oxynitride, which forms a protecting barrier layer on the fiber surface. In addition, the permanence of the flame retardant finishing was proven by laundry and abrasion tests.
authors.affiliation: †Deutsches Textilforschungszentrum Nord-West gGmbH, Adlerstrasse 1, D-47798 Krefeld, Germany.|‡University Duisburg-Essen, Institute of Physical Chemistry and Center for Nanointegration, Duisburg-Essen, Universitätsstraße 5, D-45117 Essen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mayer-Gall
authors.affiliation: †Deutsches Textilforschungszentrum Nord-West gGmbH, Adlerstrasse 1, D-47798 Krefeld, Germany.
authors.forename: Dierk
authors.initials: D
authors.lastname: Knittel
authors.affiliation: †Deutsches Textilforschungszentrum Nord-West gGmbH, Adlerstrasse 1, D-47798 Krefeld, Germany.|‡University Duisburg-Essen, Institute of Physical Chemistry and Center for Nanointegration, Duisburg-Essen, Universitätsstraße 5, D-45117 Essen, Germany.
authors.forename: Jochen S
authors.initials: JS
authors.lastname: Gutmann
authors.affiliation: †Deutsches Textilforschungszentrum Nord-West gGmbH, Adlerstrasse 1, D-47798 Krefeld, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Opwis
keywords: cotton; permanent flame retardant finishing; photochemical immobilization; polyester/cotton blends; polyphosphazenes; textiles