Synthesis And Characterization Of Polyhedral Oligomeric Silsesquioxane And Study On Fire Resistance Property Of Cotton Treated By IT

Cotton fabric has been widely used in clothing, decoration materials and other fields because of its wide range of sources, good moisture absorption, favorable air permeability and degradation easy. It is the most popular textile in the world.However, the limiting oxygen index value(LOI) of cotton fabric is 18. It is flammable material and easy to cause fire. According to statistics, 50% conflagration are caused by the fire of the textile every year, so the flame retardant textiles in the occupation safety, interior decoration, fire materials and other fields have been widely used. Many years of life practice and scientific research show that the rational use of flame retardant is one of the strategic measures to prevent and reduce the fire. It is necessary to finish the flame retardant cotton fabric in order to broaden its application field.Polyhedral Oligomerie Silsesquioxane(POSS) is a kind of nano scale cage structure of the polymer, which was called cubic silane. POSS has a well-defined structure and very small scale(Its diameter is 1~3nm). It is composed by RSiO1.5. Its interior is composed of Si, O inorganic skeleton(kernel), external covered by the organic substituents R(shell). It is a organic / inorganic hybrid composite. So it has the character both organic and inorganic nano materials. Such as good reactivity and good heat resistance. POSS has broad applications in textiles, such as fabric water and oil repellent finishing, anti crease finishing, flame retardant finishing. But POSS insoluble in water, soluble in tetrahydrofuran, toluene and chloroform and other organic solvents. When it is used in flame retardant finishing, generally by meltspinning finishing or directly in the organic solvent on the fabric finishing, so for cotton fabric flame retardant finishing has certain limitations.First of all, the synthesis process of epoxy-POSS was studied. Epoxy POSS was synthesized with the catalyst 3-epoxy propyl silane oxygen radicals three oxygen radicals(KH-560) as raw materials under the action of tetramethyl ammonium hydroxide as catalyst. The synthesis process of epoxy POSS, including the effect of temperature and mass ratio on the properties of the product was discussed. The epoxy value of POSS was determined by chemical method.The thermal resistance of POSS was determined by thermogravimetric analysis. The structure of the synthesized POSS was analyzed by infrared spectroscopy and the molecular weight was measured by gel permeation chromatography. Then the preparation of the emulsion of epoxy group POSS was studied, The HLB value of the epoxy POSS was determined by using Span-60 and Tween-80. On the basis of this, a proper surfactant was selected to emulsify epoxy POSS to water as solvent. Finally, the flame retardant finishing of cotton fabric was carried out with POSS and ammonium phosphate(APP),The oxygen index, vertical combustion performance, thermal weight loss, etc. of the fabric were determined, and the suitable ratio of POSS and APP was determined. At the same time. the treated cotton fabric whiteness, water repellency and wrinkle resistance were tested. The results showed that:(1) The optimal mass ratio of KH-560 and 5% four methyl ammonium hydroxide was 4:1, the yield of the epoxy group POSS was 72%, the suitable dehydration and condensation temperature was 80℃, the epoxy value was 0.50moL/100 g. The main synthesized epoxy group POSS was T8, at the same time containing a small amount of T6 and no rule, trapezoid and partial condensation of epoxy group POSS. The thermal gravimetric analysis of the epoxy group POSS was carried out that the temperature at the weight loss 5% was 175℃, quick weight loss temperature was200℃, 33.5% and the carbon yield at 800℃ was 33.5%, so the epoxy group POSS had a good heat resistance.(2) The HLB value of the epoxy POSS was 7,that determined by emulsion method. Based on this, the compound emulsifier was selected as non ionic surfaceactive aglycerol monostearate(HLB=10.64)and anionic surfactant sodium dodecyl benzene sulfonate sodium(HLB=10.64). And the quality ratio of glycerol monostearate(HLB=3.8) and anionic surfactant sodium dodecyl benzene sulfonate sodium(HLB=10.64) was 9.1: 8. The quality of the compound emulsifier was 10% of the quality of epoxy group POSS.(3) The quality ratio of the epoxy group POSS and APP was 6:4, that determined by orthogonal test. The flame retardant finishing process was 15% epoxy group POSS and 10% APP as a composite flame retardant finishing agent, and the flame retardant finishing was carried out under the conditions of two dip two rolling, rolling fluid rate was 90%, 100℃ 3min preliminary drying and 150℃ 3min baking. Under the condition, the LOI of treated cotton fabrics was 40.70, continued burning and smoldering time were 0s and the damaged length was 1.5cm, the treated cotton fabric of rapid weight loss temperature was 210℃, carbon residue rate was 31%, flame retardant effect was obvious.(4) The whiteness, water repellency and anti wrinkle of pure cotton fabric and treated cotton fabric by epoxy group POSS and epoxy group POSS/APP were tested.The whiteness of cotton fabric treated by epoxy group POSS/APP was decreased, but not significantly. The static contact angle and wrinkle recovery angle of cotton fabric treated by epoxy group POSS/APP were 130.9° and 180°. The whiteness of cotton fabric treated by epoxy group POSS/APP was decreased, but water repellency and wrinkle resistance were higher than pure cotton fabric or cotton fabric treated by the epoxy group POSS or APP.