Preparation And Applied Research Of Organic Acid Lanthanum Montmorillonite To Thermal Stability Of PVC

It is well known that polyvinyl chloride (PVC) has been widely used in many fields for theiradvantages of easy processing, good performance, low flammability and low cost. However, the thermalinstability and brittleness of PVC is a main limitation to its use during practical processing. Moreover, PVCis one of the largest resin burning smoke production when forced combustion, the environment andpersonal safety have great harm, which seriously affected its widely application and service life. In recentyears, MMT has been extensively used as polymer nanocomposite filler. A great number of studies havedemonstrated that rare earth elements have an excellent thermal stabilization effect on PVC. Therefore,study of organic lanthanum montmorillonite on thermal, mechanical and flame retardant and smokesuppression performance of PVC is important.A series of thermally stable lanthanum organic montmorillonites (La-OMMTs) were successfullyprepared by modifying Na-MMT with anionic surfactants and lanthanum chloride. The La-OMMTs werecharacterized with XRD, FTIR, TGA and ICP. The effective of the La-OMMTs to polyvinyl chloride wastested by TGA, Congon Red, mechanical properties test and cone calorimeter. Obtain the followingconclusion:1. Optimized by single factor experiment, modify La-MMT by reacting with three anionic surfactantsto produce effectively intercalated La-OMMT. The pH of the Na-MMT suspension was then adjusted toapproximately5with hydrochloric acid. The LaCl36H2O solution was added dropwise to the MMTsuspension under continuous, vigorous stirring at60°C for2h.2. TGA result show that organic content of La-OMMT have reached about30%and the intercalationof SDSo into La-OMMT resulted in its excellent thermal stability. La-OMMT-SDDhas a higher amount ofLa (11.99%) observed by ICP.3. La-OMMT/PVC nanocomposites prepared by melt intercalation method. La-OMMT-SDDexhibitedsuperior thermal stability based on the TGA analysis, the onset decomposition temperature is31.64℃higher than pure PVC. Moreover, the mechanical properties test show that the impact strength of3%La-OMMT/PVC nanocomposites compared with pure PVC increased by69.51%.4. Flame and smoke suppression performance tests show, La-OMMT played a significant role in thePVC flame combustion process, the peak release rate of La-OMMT-SMDP/PVC nanocomposites reduced to131.48kw/m2. However, smoke suppression performance is not satisfactory.