Research On Poly Methyl Phosphonic Acid Glycol Ester(PEMP) Flame Retardant Treatment On Cotton Fabric

Cotton fabric has good air permeability,water-absorption,comfort and other excellent properties,which is often used for clothing fabrics,quilt,bed sheet,curtain and so on in daily life.But the cotton fabric is easy to burn.This feature largely limits the use of cotton fabric.Therefore,this paper involves researches about how to reduce the flammability of cotton fabrics.In this paper,dimethyl methyl phosphoric acid(DMMP)and ethylene glycol(EG)are performed as raw materials,creating a kind of intermediates--catalytic synthesis of organic phosphoric acid estercalled poly methyl phosphoric acid glycol ester(PEMP).After testing the acid value,phosphorus content,degree of polymerization of the PEMP,and analyzing structure of the product with Fourier infrared spectrum(FTIR)and nuclear magnetic resonance(NMR),through usingon-line with high performance liquid chromatography(HPLC)-mass spectrometry(HPLC-MS),analyzing the composition of the product and the degree of polymerization,gas chromatography-mass spectrometry(GC-MS)online analysis of the composition of by-product,and optimizing the PEMP synthesis conditions.To process the cotton fabric,the author used the independently-synthesized flame retardant,poly methyl phosphoric acid glycol ester(PEMP);in order to process the cotton fabric,PEMP on cotton fabric flame retardant properties,mechanics performance,thermal stability and the influence of fire behavior were studied.Mechanical properties showed that after adding this flame retardant,the mechanical properties of cotton cloth is not affected in a large degree.The limit oxygen index value(LOI)of cotton cloth increased as we added more and more flame retardant.Therefore,when the adding amount of flame retardant was 20%,the limit oxygen index of longitudinal cotton cloth reached to 31.4%,it is 10.4% higher than the blank cotton.And the limit oxygen index of latitudinal cotton cloth reached to 29.8%,which is higher than the blank cotton cloth by 10.0%.According to the results of vertical combustion,after adding the flame retardant,the continuous burning time of cotton cloth is reduced.Also,the smoldering time and damage length of cotton cloth were reduced.The results of Cone Calorimeter show that the ignition time of blank cotton cloth is 22 s,which means that it is easy to ignite;meanwhile,the ignition time of flame retardant cotton cloth was none,which means that it is not ignited at all.The pkHRR value of pure cotton cloth is 149.01 kW/m2,the pkHRR value of flame retardant cotton cloth was 15.40 kW/m2.The Peak heat release rate of flame retardant cotton cloth is far less than of pure cotton cloth.The THR of flame retardant cotton cloth is 0.76 MJm-2 kg-1,which is far less than 4.85 MJm-2 kg-1 of pure cotton cloth.According to the results of water tolerance,after five times' washing,the flame retardant of the cotton cloth was not significantly reduced.Through scanning electron microscopy(SEM)test,we observed and compared the microstructure of pure cotton cloth and flame retardant cotton cloth before and after the combustion.Then we found that during the combustion,the microstructure of blank cotton cloth was significantly changed,while that of flame retardant cotton cloth was not significantly changed.The result in thermo-gravimetric analysis observes that in the aspect of the initial decomposition temperature,the flame retardant cotton cloth is also lower than the pure cotton cloth.In the meantime,the degradation temperature range and the maximum thermal decomposition rate of thermal degradation peak of flame retardant cotton cloth both relatively move in the direction of low temperature as the pure cotton cloth,whereas the residual carbon of flame retardant cotton cloth under 800 ? significantly increased.And the hot weightlessness peak shape or the amount of carbon residue under 800 ? is basically the same no matter the pure cotton cloth or the one with 20% added PEMP.By using the Flynn-WallOzawa method to study the kinetics of thermal degradation of PEMP flame retardant cotton cloth,the results showed that the blank cotton cloth thermal degradation activation energy remained constant,while the thermal degradation activation energy of flame retardant cotton cloth was changed with temperature.At the first stage,the phenomenon that thermal degradation activation energy is lower than that of the pure cotton cloth is due to the thermal degradation of PEMP flame retardant.At the second stage,activation energy of this reaction rises obviously.According to the results of thermo-gravimetric infrared analysis,the thermal degradation temperature of blank cotton and flame retardant cotton range are different,they have different degradation products,for the flame retardant cotton cloth,its degradation products in different time is different,also,blank cotton thermal degradation products of infrared absorption peak height above the flame retardant cotton sample degradation products of infrared absorption peaks,the volatiles quantity of flame retardant cotton cloth reduced after pyrolyzed.