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

Abstract

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.

Thermogravimetric studies of the effect of lead decanoate on the thermal degradation of poly(vinyl chloride)

“…Decomposition in air was found to begin a t a much lower temperature (473 K) [17]. However, in both cases more than the theoretical quantity of hydrogen chloride was observed to be lost a t the end of degradation, an evidence that the end of dehydrochlorination was subsequently followed by breakdown of the conjugated system.…”

Epoxidized linolenic acid salts as multifunctional additives for the thermal stability of plasticized PVC

“…Iida et al 12,13 studied epoxidized polybutadiene as a thermal stabilizer alongside calcium and zinc stearate. Similarly, Odilora 23 showed that the time to reach one percent dehydrochlorination and the rate of dehydrochlorination at that time are both improved when metal carboxylates are used in addition to epoxidized oils. A study by Okieimen 15 examined the stabilizing effects of jatropha seed oil, khaya seed oil, and rubber seed oil along with metal soaps (Ba and Cd) of the epoxidized oils.…”