Improvement of the processability and thermal stability of poly(vinyl chloride) with 5,6-diamino-1,3-dimethyluracil

Uracil derivatives are potential nontoxic thermal stabilizers of poly(vinyl chloride) (PVC) and have a better stabilization effect. 5,6-diamino-1,3-dimethyluracil (DDU) was investigated as a thermal stabilizer for PVC. The stabilization effect of DDU was measured by thermogravimetric analysis, thermal aging test, and recording the time of the color change of the Congo red paper (Congo red test). Meanwhile, the processability of PVC stabilized by DDU was investigated through dynamic performance test. The results showed a better stabilizing effect compared with calcium stearate (CaSt 2 ) and zinc stearate (ZnSt 2 ). To explain the stabilization of DDU, the probable mechanism was suggested that DDU absorbed and chemically bonded with hydrogen chloride. Therefore, DDU could be used as a thermal stabilizer of PVC.