Stabilization of rigid poly(vinyl chloride) by 5,6,7,8-Tetrahydro-2-mercapto-4-(p-methoxyphenyl)-3-quinolinecarbonitrile

The chemical 5,6,7,8-Tetrahydro-2-mercapto-4-(p-methoxyphenyl)-3-quinolinecarbonitrile (TMQC) has been investigated as a thermal stabilizer for rigid poly(vinyl chloride) (PVC) at 180°C in air. The results reveal the higher stabilizing efficiency of the investigated material, as shown by the longer induction period obtained in its presence relative to those produced by commonly used industrial stabilizers. Ultraviolet irradiation of the polymer stabilized by TMQC gives a lower extent of discoloration compared to that of unstabilized PVC. Reaction of TMQC with the polymer in solution also has been studied in order to investigate the mechanism of stabilization.