Hybrid silica-phytic acid coatings: Effect on the thermal stability and flame retardancy of cotton

0510622 - ÚFM 2020 RIV CH eng J - Článek v odborném periodiku
Barbalini, M. - Bertolla, Luca - Toušek, J. - Malucelli, G.
Hybrid silica-phytic acid coatings: Effect on the thermal stability and flame retardancy of cotton.
Polymers. Roč. 11, č. 10 (2019), č. článku 1664. E-ISSN 2073-4360
Institucionální podpora: RVO:68081723
Klíčová slova: Cotton * Durability * Flame retardancy * Phytic acid * Sol-gel processes * Solid state NMR spectroscopy * Thermal stability
Obor OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics
Impakt faktor: 3.426, rok: 2019
Způsob publikování: Open access
https://www.mdpi.com/2073-4360/11/10/1664/htm

New hybrid sol-gel coatings based on tetraethoxysilane (TEOS) and phytic acid (PA) were designed and applied to cotton, the flame-retardant properties of the treated fabrics were thoroughly investigated by means of flame-spread and forced-combustion tests. The first goal was to identify the TEOS:PA weight ratio that allowed the achievement of the best flame-retardant properties, with the lowest final dry add-on on the fabrics. Therefore, different TEOS:PA sols were prepared and applied to cotton, and the resulting coated fabrics were thoroughly investigated. In particular, solid-state NMR spectroscopy was exploited for assessing the condensation degree during the sol-gel process, even for evaluating the occurrence of possible reactions between phytic acid and the cellulosic substrate or the alkoxy precursor. It was found that a total dry add-on of 16 wt. % together with 70:30 TEOS:PA weight ratio provided cotton with self-extinction, as clearly indicated by flame-spread tests. This formulation was further investigated in forced-combustion tests: a significant reduction of heat release rate (HRR), of the peak of HRR, and of total heat release (THR) was found, together with a remarkable increase of the residues after the test. Unfortunately, the treated fabrics were not resistant to washing cycles, as they significantly lost their flameretardant properties, consequently to the partial removal of the deposited hybrid coatings.
Trvalý link: http://hdl.handle.net/11104/0301605