Effects of mixed metal stearates on thermal stability of rigid PVC

As a representative commercial heat stabilizer, Al 4180 was characterized by spectroscopic and thermal analysis techniques and used in thermal stabilization of rigid PVC. Al 4180 was a mixture of stearates of Al(III), Zn(II), Pb(II) and Ca(II) and metal hydroxides such as Al(OH)(3). Observed acceleration of dehydrochlorination of PVC was explained by the inefficient mixing of the stabilizer with PVC and formation of dehydrochlorination catalyst, ZnCl2 and AlCl3 on heating the films. (C) 1999 Elsevier Science Ltd. All rights reserved