Synthesis And Application Of Flame Retardants For The Treatment Of Cotton Fabrics

Cotton is the most important textile fiber for apparel use and is preferred over synthetic fibers due to its better comfort and feel than synthetic fibers. However, the flammability of cotton fabrics and the emission of high levels of formaldehyde during its flame retardant treatment and uses limited its wide uses in many fields.Flame retardants, poly(1,2-dicarboxyl ethylene spirocyclic pentaerythritol bisphosphonate )(PEPBP) was synthesized and applied in flame-retardant treatment for pure cotton fabrics. Their chemical structures were characterized by FT-IR. Flammability of the treated fabrics was investigated by Limiting Oxygen Index (LOI) and Vertical Burning Test.The char-forming tendency and flame-retardant mechanism of PEPBP for cotton fabrics were investigated by thermogravimetric analysis (TGA), scanning electron microscope (SEM) and digital photograph. By investigating thermo-oxidative decomposition kinetics, we analyzed the effect of PEPBP on the decomposition process of cotton fabrics and its effect on flammability of the fabrics.The flammability of PET/Cotton blend fabrics was investigated after the fabrics were treated by lemon acid and APP simultaneously and respectively.Results show that PPPBP and APP can improve the fire resistance of cotton and PET/cotton fabrics to a great extent respectively. When the add-on of PEPBP reaches 21.2%, the LOI of the treated cotton fabric increases to 33.8. Besides, PEPBP improves after-flame of cotton fabrics during combustion. The char, most of which is the decomposing product of PEPBP, has outstanding thermal resistance. The char-forming property and the structure of PEPBP have direct relationship with the improved fire resistance of PEPBP treated cotton fabrics. Kinetic analysis shows that at low conversion rate, the Ea of untreated fabric is higher than that of the treated. However, at high conversion rate, the Ea of untreated fabric is lower than that of the treated. LOI of the APP treated PET/cotton fabric reaches 25.8. TGA curves show that APP lowers the initial decomposition temperature of cotton fabrics. However, at high temperature range, APP treated fabrics have higher residue rate. Flame retardancy of lemon acid and APP treated PET/Cotton (35/65) blend fabric is also improved, but it is not obvious. The LOI of the treated blend fabric just reaches 25.6.