Preparation And Flame Retardant Properties Of Polyacrylic Acid Based Attapulgite Nanocomposites

Cotton fabric and leather are very popular because of their good hydrophilicity,excellent biodegradability and comfortable performance.However,it endangers human life and property safety because of its flammability.Therefore,it is a great significance to give cotton fabric and leather with excellent flame retardancy.Attapulgite(ATP)is a silicate flame retardant,which contains no halogen and does not produce toxic gas and smoke during combustion.In this study,attapulgite was introduced into acrylic acid matrix,to prepare polyacrylic acid / attapulgite nanocomposite flame retardant materials.The composite flame retardant materials were used in the leather retanning and cotton finishing process.Finally the effects of flame retardancy on the retanned leather and the finishing cotton fabrics were explored.The specific research contents were as follows:First,the acidification treatment of ATP is carried out,and then ATP after acidification treatment modified by gamma methacryl propyl tri methoxy silane(KH-570)modified,the modified ATP polymerized in situ with acrylic acid(AA)to abtain the polyacylic acid/attapulgite(PAA/ATP)nanocomposite was prepared.The results showed that the acidification of ATP had the best dispersibility when the concentration of hydrochloric acid was 8 mol/L.The contact angle of ATP surface was the largest when the mass ratio of KH-570 and ATP was 1:1.The static stability of PAA/ATP nanocomposites was the best when the dosage of ATP was 1%.Transmission electron microscopy(TEM)showed that the ATP could be dispersed uniformly in the composites.The results of thermogravimetric analysis(TGA)showed that introducing ATP into polyacrylic acid system could improve the thermal stability of composites siginificantly.The application results also showed the flame retardancy of retanned leather and finished cotton fabric were better when ATP was 1%.Compared with unfinished fabrics,the limit oxygen index(LOI)of cotton fabric treated with PAA/ATP nanocomposites increased from 18.5% to 22.7%.Compared with the PAA retanning leather,the LOI of the retanned leather treated with PAA/ATP nanocomposite was increased from 15.7% to 16.4%,and the combustion rate decreased from 0.072 mm/s to 0.045 mm/s.The bi-function modified attapulgite(BF-ATP)was prepared by KH-570 and isopropyl-three-(two-octyl-pyrophosphate)-titanate(NDZ-201),and then the polyacrylic acid/bi-function modified attapulgite(PAA/BF-ATP)nanocomposite was prepared by BF-ATP and AA in situ polymerization.When the mass ratio of KH-570 and NDZ-201 was 1:19,the grafting rate of NDZ-201 was the highest.When the amount of BF-ATP was 1.5%,the PAA/BF-ATP nanocomposite was the stablest.TEM results showed that BF-ATP could be dispersed uniformly in composite materials.The results of TGA showed that the thermal stability of the PAA/BF-ATP nanocomposites was better.The application results showed that when the BF-ATP content in PAA/BF-ATP was 1%,the flame retardancy of finished cotton fabric was the best.Compared with unfinished fabrics,the LOI of finished cotton fabric treated with PAA/BF-ATP nanocomposites increased from 18.5% to 23.5%.When the amount of BF-ATP in PAA/BF-ATP is 1.5%,the flame retardant of retanned leathers was best.Compared with the PAA retanning leather,the LOI of the retanned leather treated with PAA/ATP nanocomposite was increased from 25.0% to 26.1%,and the combustion rate decreased from 0.072 mm/s to 0.032 mm/s.Compared with the application results of PAA/ATP,the flame retardancy of retanned leather and finished cotton fabrics by PAA/BF-ATP had been improved,the LOI value of the finished fabric was increased by 0.8%,and the LOI value of the retanned leather sample increased by 0.4%.It was mainly due to the synergistic effect of ATP,Si and P elements in the modifier.In order to further improve the flame retardancy of cotton fabric and leather,nano Zn O was introduced into PAA/BF-ATP nanocomposites by in situ polymerization to prepare polyacrylic acid / bi-function modified attapulgite / zinc oxide(PAA/BF-ATP/ZnO)nanocomposites.TEM results showed that rod like BF-ATP and spherical Zn O were dispersed uniformly in the composites.The application results showed that when the amount of ZnO in PAA/BF-ATP/ZnO was 0.4%,the flame retardant performance of retanned leathers and finished cotton fabric was better.Compared with unfinished cotton fabric,the LOI of the finished cotton fabric by PAA/BF-ATP/ZnO increased from 18.5% to 24.4%.Compared with PAA retanned leather,the LOI of leather by PAA/BF-ATP/ZnO nanocomposites increased from 25.0% to 26.4%,the burning rate was reduced from 0.072 mm/s to 0.009 mm/s.Compared with the application results of PAA/BF-ATP,the flame retardancy of PAA/BF-ATP/Zn O retanning and finished fabrics has been improved because of the synergistic effect among ATP with P element and ZnO.The LOI value of the finished fabric was increased by 0.9%,and the LOI value of the retanned leather samples was increased by 0.3%.At the same time,the PAA/BF-ATP/ZnO nanocomposite finished cotton fabric had the better UV protection performance.