Study On The Synthesis And Application Of Nano Layered Mgal-Hydrotalcite

This paper studied Mg,Al-hydrotalcite preparation based on the coprecipitation method and hydrothermal method.The samples were characterized by XRD,FT-IR and TG-DTA,it was mainly discussed whether the crystallization time,crystallization temperature, the molar ratio of magnesium and aluminum,the variety and dosage of surfactant have an effect on particle size and stacking layers.The results show that particle size and stacking layers were wider by hydrothermal method,and they were smaller with adding surfants,?The crystallization time and temperature have an optimal value,but not the higher the better.Salicylate-pillared hyrotalcites have been successfully assembled by ion exchange of MgAl-CO32--LDHs precursor in alcohol under temperature of 150℃hydrothermal conditions.In order to prepare high efficient non-toxic composite thermal stabilizer,in this paper LDHs composited with Ca/Zn and organotin,then the complex was used in rigid PVC. Studied the thermal stability and processing theological property of PVC with thermal stabilizer through double-roll rolling thermal aging test, oven static thermal aging test Congo red test, chromatic meter, thermogravimetic analysis and torque rheometer.The resuts showed , as PVC thermal stabilizer,LDHs had positive synergic effect with Ca/Zn and organotin,but the adding dosage could not put overmuch ,otherwise it would happen reunion phenomenon,CaSt2 cannot only have long-term thermal stability,but also have good internal luricity , organozinc can improve the initial colour, but the adding dosage can not put overmuch ,otherwise it would cause"zinc burning",meanwhile,it can make system viscosity rise, torque rise and processing rheological become worse, studied the processing rheological of dibutyltindilaurate(DBTL),dibutyltinmaleate(DBTM)and methyltin mercaptide,and the results showed that DBTL had more luricity,and the others had same processing rheological, the effect of three tins on showed thermal stability of PVC was analyzed by dynamic thermal aging test,the result is as follows: methyltin mercaptide> DBTM > DBTL,the more methyltin mercaptide contents,the better thermal stability,but it can cause system viscosity, balance torque obviously higher, processing rheological become worse, and also improve the cost of stabilizers PVC processing.Compared self-made stabilizer with the products in the markets through dynamic,static thermal aging test and torque rheomety,the result showed that self-made stabilizer had better thermal stability and better processing theological property.The composite thermal stabilizer have been put into production in Chuzhou Hongyuan Paint Spraying company,which has replaced its former thermal stabilizer in PVC home applicances.