On the thermal degradation of poly(vinyl chloride). Synergistic effect of mixtures of lead and zinc carboxylates

The effect of a mixture of lead and zinc carboxylates on the thermal decomposition of poly(vinyl chloride) in air is studied. The results obtained by weight loss determination and IR and UV spectroscopic analysis showed a marked influence of these compounds on the degradation of PVC. The greatest stabilization was achieved with lead dodecanoate. With a mixture of lead octadecanoate and zinc octadecanoate an indication of synergism was observed leading to enhanced stabilization. With the mixture of lead and zinc dodecanoate the level of stabilization was less; this mixture catalysed the degradation of PVC at 473 K. The mechanism of the stabilization of PVC by the studied compounds is discussed.