ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Influence of metal stearates on thermal stability of poly(vinyl chloride). 4. Lead stearate

P. Šimon, J. Oremusová, and L. Valko

Department of Physical Chemistry, Faculty of Chemical Technology, Slovak Technical University, CS-812 37 Bratislava

Abstract: Kinetics of dehydrochlorination of poly(vinyl chloride) stabilized with lead stearate is examined and the kinetic data are completed with viscosimetric determination of relative molecular mass of the samples thermally stressed. The results show that lead stearate is a very efficient scavenger of HCl split off from PVC. The values of effective rate constants of dehydrochlorination decrease hyperbolically with increasing relative mole fraction of lead stearate in the blend. This led to the conclusion that lead stearate exerts a blocking effect on the propagation stage of the zip reaction. A reaction mechanism of the dehydrochlorination is suggested and the rate constants of individual reaction steps are obtained by comparing the calculated and experimental kinetic runs. Some general aspects of the dehydrochlorination of PVC stabilized with metal stearates are discussed.

Full paper in Portable Document Format: 453a389.pdf

Chemical Papers 45 (3) 389–399 (1991)