Preparation、Characterization And Flame Retardant Properties Of Silicate Intercalated Calcium Aluminum Hydrotalcite Flame Retardant For Flame Retardant Of Bamboo

The flammability of bamboo material greatly limits its wide application in construction,decoration and other fields.In order to improve the flame retardant and smoke suppression properties of bamboo,silicate intercalated calcium aluminum hydrotalcite(CaAl-SiO3-LDHs)flame retardant by using silicate intercalation modified technology were prepared in this article,the different modified preparation technology,structure and performance of calcium aluminum hydrotalcite,and the flame retardant treatment process,the flame retardant smoke suppression performance of bamboo materials treated with silicate intercalated calcium aluminum hydrotalcite were discussed.The main results are as follows:(1)CaAl-SiO3-LDHs were prepared by co-precipitation method and hydrothermal method,the two preparation processes of CaAl-SiO3-LDHs and their advantages and disadvantages in structure and performance were discussed.The results show that:CaAl-SiO3-LDHs prepared by coprecipitation has higher crystallinity,more uniform particle morphology,smaller particle size,and higher thermal stability.Therefore,the coprecipitation method is the preferred method for preparing CaAl-SiO3-LDHs;The best process parameters for preparing,crystallization time for 9h,the Ca2+concentration is 0.33mol/L(Ca2+:Al3+=2).(2)The bamboo samples were impregnated with CaAl-SiO3-LDHs suspension flame-retardant treatment by atmospheric impregnation,ultrasonic impregnation and pressure impregnation.The results show that the bamboo flame retardant drug loading rate increases with the increase of the pressure impregnation pressure.When the pressure exceeds 0.6 MPa,the bamboo drug loading rate tends to be stable.It can be up to 10.75%,so pressure impregnation is the best method for CaAl-SiO3-LDHs flame retardant treatment of bamboo.(3)After adopting CaAl-SiO3-LDHs to carry out flame retardant treatment on bamboo,the microstructure,element content,and flame retardant and smoke suppression properties of bamboo before and after flame retardant treatment were studied with SEM,EDX,and CONE calorimeter.The result shows:① CaAl-SiO3-LDHs flame retardant can enter bamboo thin-walled cells,ducts,pores and other structures,and the Ca,Al,Si content of bamboo surface is 1.91%,1.24%,0.23%respectively;②After the bamboo materials were flame-retarded by CaAl-SiO3-LDHs,the time for combustion to reach the peak of heat release rate(HRR)is delayed by 30s,the total heat release amount(THR)is reduced by 30.89%,and the average mass loss rate(pMLR)is reduced by 7.36%,the ignition time(TTI)is delayed by 14s,and the residual carbon rate is increased by 16.54%;③Compared with non-flame retardant materials,the total smoke emission(TSP)is reduced by 38.94%,and the carbon monoxide production(COP)and carbon monoxide production(Yco)both tend to zero;④CaAl-SiO3-LDHs flame retardant bamboo has good flame retardant and smoke suppression properties.