IMPROVEMENT OF THE FLAME RETARDANT PERFORMANCE OF COTTON FABRICS USING SILANE-PHOSPHATE BASED SOL-GEL SYSTEM
TEKSTIL VE MUHENDIS, vol.33, no.143, pp.148-159, 2026 (Scopus, TRDizin)
- Publication Type: Article / Article
- Volume: 33 Issue: 143
- Publication Date: 2026
- Doi Number: 10.7216/teksmuh.1939122
- Journal Name: TEKSTIL VE MUHENDIS
- Journal Indexes: Engineering Source (EBSCO), Scopus, Central & Eastern European Academic Source (CEEAS), Compendex, TR DİZİN (ULAKBİM)
- Page Numbers: pp.148-159
- Dokuz Eylül University Affiliated: Yes
Abstract
In this study, a hybrid sol-gel formulation based on silane and phosphorus/nitrogen containing components was applied to cotton fabrics to enhance their flame-retardant properties. Prior to the application, a high concentration alkaline pretreatment was performed to induce intramolecular swelling within the cellulose structure, reorganize hydrogen bonding and increase the accessibility of reactive hydroxyl groups. The sol-gel system was developed by integrating flame retardant additives including phytic acid, phosphoric acid, guanidine phosphate and urea into a silanol network formed by TEOS and GPTMS precursors. The prepared formulation was applied onto the fabric surface via padding method followed by thermal curing to form a three-dimensional hybrid structure. FTIR and XPS analyses confirmed the successful formation of a Si-O-Si network on the fabric surface and the incorporation of phosphorus containing components into the system. TGA results demonstrated that the sol-gel coating improved the thermal stability by increasing the degradation temperature. LOI and flame spread tests revealed a significant enhancement in flame retardant performance after coating with LOI values exceeding 52%. However, post-washing FTIR and XPS analyses indicated a noticeable reduction in phosphorus- and nitrogen containing species, which corresponded to a decrease in LOI to approximately 28%. Optical microscopy further confirmed that although a homogeneous coating layer was initially formed on the fiber surface this layer became thinner after washing. The findings indicate that while the silane-based inorganic network forms a relatively stable structural backbone on the fabric surface, the flame-retardant performance is largely governed by phosphorus and nitrogen-containing additives. The partial loss of these components during washing suggests that the interaction between the additives and the substrate is not sufficiently strong. Therefore, this study demonstrates that achieving durable flame retardancy requires not only the deposition of functional additives onto the surface but also their covalent integration with both the cellulose structure and the silane network.