Flameproofing modification of synthetic materials by laser radiation

Abstract

677.46.494:536.46 L. G. Panova, T. V. Kulikova, O. A. Grishina, V. A. Shteinle, and M. V. ZagoruikoV. I.A method of giving flameproof properties to materials and articles in light industry by modification with phosphorus-containing flame retardants under the effect of the energy from CO 2 laser radiation was developed. The optimum modification parameters (LR power density of 5.3 W/cm 2 , treatment time of 30 sec, concentration of flame retardant (FR) in 5-10% solution, impregnation time of 100-120 sec), which allow obtaining flameproof materials with high performance properties were determined. The oxygen index of the cloth increased to 29.5-42%, the breaking strength increased by 8.5-21%, and the abrasion resistance increased by 5-12% without worsening the hygroscopicity and air permeability. The activating effect of laser radiation on the modification process was demonstrated; it resulted in an increase in the sorption capacity of the fibre structure of the materials, diffusion of FR into the bulk of the fibres, uniform distribution of the fibres in the form of finely disperse particles, intensification of the reaction of the components, ordering of the structure, and improvement in the physicomechanical properties of materials and articles in light industry. The method saves on expensive raw materials flame retardants due to conducting the modification from lowconcentration solutions and allows expanding the line of flameproof materials.To increase the quality of textile materials or give them specific properties flameproofing, water-resistance, bactericidal, etc., physicochemical methods of treating the surface of fibres and fabrics are widely used to form active centers. They include treatment of the materials in the gaseous medium of corona glow discharge, high-frequency plasma treatment, photochemical treatment using UV radiation, radiation treatment with a fast electron beam [1][2][3][4][5], and treatment with laser radiation [6,7]. However, there are no studies on utilization of the energy of laser radiation (LR) in modification processes to give flameproof properties to materials and articles in light industry. For this reason, a method must urgently be developed to give materials and articles in light industry low combustibility by modification with different phosphorus-containing flame retardants using the energy of CO 2 laser radiation for activating their reaction.We used the phosphorus-containing compounds Phosdiol-A (PD) and dimethyl methylphosphonate (DMMP) and the phosphorus-nitrogen-containing compound methyl phosphonamide T-2 (T-2). Fabrics, nonwovens, and fibres made from synthetic fibre-forming polymers were modified poly(ethylene terephthalate) (lavsan), polyacrylonitrile (nitron), and polycaproamide (capron). Flameproofing treatment of the textile materials was conducted with aqueous solutions of the flame retardants investigated in a concentration of 3 to 50% under the effect of LR and impregnation without LR.We know [8-10] that polymers selectively absorb LR whose bond vibration frequenc...