Preparation and Mechanism of Flame-Retardant Cotton Fabric with Phosphoramidate Siloxane Polymer through Multistep Coating

To improve the water solubility of phosphoramidate siloxane and decrease the amount of flame-retardant additives used in the functional coating for cotton fabrics, a water-soluble phosphoramidate siloxane polymer (PDTSP) was synthesized by sol-gel technology and flame-retardant cotton fabrics were prepared with a multistep coating process. A vertical flammability test, limited oxygen index (LOI), thermogravimetric analysis, and cone calorimetry were performed to investigate the thermal behavior and flame retardancy of PDTSP-coated fabrics. The coated cotton fabrics and their char residues after combustion were studied by attenuated total reflection infrared spectroscopy (FTIR-ATR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). All results presented that PDTSP-coated cotton fabrics had good flame retardancy and char-forming properties. PDTSP coating was demonstrated to posess gas-phase flame-retardant mechanism as well as a condensed phase flame-retardant mechanism, which can be confirmed by thermogravimetric analysis-Fourier transform infrared spectroscopy (TG-IR) and cone calorimetry test. Also, the preparation process had little effect on the tensile strength of cotton fabrics, although the air permeability and whiteness had a slight decrease. After different washing cycles, the coated samples still maintained good char-forming properties.

Vinyl-functionalized polysiloxane as radical scavenger during the degradation of poly(vinyl chloride)

Siloxane polymer containing vinyl groups was blended with poly(vinyl chloride) (PVC) to convey plasticization and stability against decomposition, that is likely to happen during thermal processing or following exposure to the ultraviolet (UV) light. The immiscibility between silicone rubber and PVC was proved from images acquired using scanning electron microscopy (SEM), which revealed worsening of the situation at higher loading (10 wt%) of silicone polymer. The thermal degradation profiles indicated that the inclusion of silicone polymer did not affect the thermal resistance significantly between 200°C and 350°C. However, it protected the matter from intensive decomposition at higher temperatures and increased the residual weight. Fourier transform infrared spectra were collected for the blends after exposure to UV radiation for 168 h, from which the absence of appreciable dehydrochlorination or change in the nature of the material was ensured. The hampering of dehydrochlorination is expected to have proceeded by instant attack of any appearing radicals on PVC backbone onto vinyl groups of the silicone polymer and buildup of a network structure.

Protective Coating Based on Siloxane Polymer Nanopatterned by Alkoxytitanate

The paper considers the problems of creating new protective coatings based on organosilicon polymer – polymethylphenylsiloxane, modified with tetraisopropyltitanate. The mechanisms of siloxane polymer nanostructuring have been suggested. The coating surface nanostructure and the impact of material components content and nature on its properties have been studied. To research protective surface nanostructure, the method of atomic-force probe microscopy applying IntegraAura device has been used. Nanoparticles formations with 10-20 nm effective scale have been revealed. Adhesive properties of the protective coating have been studied. Glass and metal adhesion was determined applying the method of detachment from the steel discs substrate using adhesive meter PSO-MG4. The modification was stated not to cause any substantial loss of coating adhesive properties. Simultaneously modification process was accompanied with the increase of relative coating firmness.The developed compounds and corresponding coatings are aimed at protecting buildings and constructions against negative impact of natural and anthropogenic factors.