Study On The Synergistic Effects And Application Performances Of Several Kinds Of Organic Thermal Stabilizers For Poly(Vinyl Chloride)

In this work, we broaden and deepen the research on the two kinds of organicthermal stabilizers for PVC, trihydroxymethyl aminomethane (TRIS) and1,3-dimethyl-6-aminouracil (DMAU).Their synergistic effects were studied,and the bestmass ratio were found.The results above were compared with the performances usingpentaerythritol(PER) and DMAU, or diethanolamine(DEA) and DMAU as synergisticthermal stabilizers,and mechanism were discussed.We also test the synergistic effects ofTRIS/DMAU with Ca/Zn composite stabilizer and some auxiliary stabilizers.The results indicated that: the best static and dynamic thermal stability of PVC wasobtained, when TRIS and DMAU was added at the mass ratio of2:1; These two thermalstability performances were better than those using pentaerythritol and DMAU, ordiethanolamine and DMAU as synergistic thermal stabilizers.Using discoloration test,the dehydrochlorination test and dynamic thermal stability test, the synergistic effects of1,3-dimethyl-6-aminouracil (DMAU) and trihydroxymethyl aminomethane (TRIS) asPVC thermal stabilizer were studied. As PER is able to synergize with DMAU whileDEA is not, we can suggest that the interaction between the alcoholic hydrogen of TRISand the chlorine atom might synergize with the preventing and remedying mechanismof DMAU,and the better HCl-absorbing ability of TRIS might increase the long-timestability of this systerm.TRIS/DMAU synergistic thermal stabilizer can not only act asauxiliary stabilizer with Ca/Zn composite stabilizer,but also be used together withepoxidizedsoybeanoil.However, β-diketone is not fit for this systerm because it canincrease the release of HCl.Furthermore,we studied the performances of two auxiliary stabilizers,SK-50andYS,with the Ca/Zn composite stabilizers of different Ca/Zn mass ratio,which providedhelp for the application of them.