Design of Nitrogen‐containing Organic Thermal Stabilizer with Resistance to “zinc Burning” and Its Application

Using maleic anhydride and 6-amino-1,3-dimethyluracil as raw materials, by adding zinc oxide and introducing metal ions, the aminouracil zinc maleate (AM-Zn) was synthesized. The structure of the product was analyzed by Fourier transform infrared spectroscopy and H-1 NMR spectroscopy. The molecule contains ester group, carbon-carbon double bond, carboxylate and diazo group, which can be used as the main thermal stabilizer for poly(vinyl chloride) (PVC). The thermal stability and excellent resistance to zinc burning of AM-Zn were characterized by Congo red method, thermal aging method, thermal weight loss method, electrical conductivity, and other detection methods. In addition, the compound use of AM-Zn and CaSt(2) could further improve the thermal stability performance, which was excellent compared with the commercially available CaSt(2)/ZnSt(2). The thermal stabilization effect was the best when CaSt(2)/AM-Zn = 2:1, the initial whiteness could reach 50 min, and it was not completely blackened and aged within 80 min. The static stabilization time was 65 min, and the thermal stabilization time is increased by 40 min compared with CaSt(2)/ZnSt(2). The thermal stabilization mechanism was analyzed, and the designed and synthesized AM-Zn, a multifunctional molecular structure, had a strong potential as a thermal stabilizer for PVC.