Using the double replacement reaction

lanthanum nitrate

6-methyluracil (MUA)

and ammonia water were used as raw materials to prepare 6-methyluracil lanthanum (LMUA). The product was characterized by infrared spectroscopy

thermal analysis and elemental analysis. The molecular formula is determined to be La(C5H4N2O2)NO3· 1.5H2O. Through the Congo red experiment

high temperature aging experiment and electrical conductivity experiment

the effect of LMUA on the thermal stability of PVC was studied. The results showed that when LMUA alone was used as a heat stabilizer for PVC

its thermal stability and discoloration resistance performed excellent

the static thermal stability time reached 73min

and the dynamic thermal stability time reached 88min. Combining LMUA and other heat stabilizers for binary

ternary and quaternary compounding

not only the synergy of the product was good

but also the stability was improved. When the composite stabilizer is compounded according to the mass ratio of LMUA∶CaSt2∶pentaerythritol= 3∶1∶1

the static thermal stability interval reaches 88min

and the discoloration resistance and thermal stability are the best. The light stability was analyzed by ultraviolet absorption spectrophotometry

which preliminarily verified that LMUA has light stabilization effect. LMUA can react with the HCl generated during the degradation of PVC to generate LaCl3

which reduces the catalytic effect of HCl on the degradation of PVC

thereby achieving the purpose of enhancing the thermal stability of PVC.