Synergistic effect of metal soaps and natural zeolite on poly(vinyl chloride) thermal stability

Abstract

The synergistic effect of metal soaps (zinc stearate and calcium stearate) and/or natural zeolite (clinoptilolite) on PVC thermal stability was investigated. For this purpose, PVC plastisol was prepared by mixing poly(vinyl chloride) (PVC) and dioctyl phthalate (DOP) and stabilized with different amounts of metal soaps and zeolite. Kinetic studies of dehydrochlorination at 140 and 160°C were done for unstabilized and stabilized PVC plastigels using 763 PVC Thermomat equipment. The stabilizing effect of zeolite on the increase in the induction period of the sample was considered to result from the absorption of HCl, a property that was thought to reduce the autocatalytic effect of HCl evolved at the initial stages of dehydrochlorination. Since the induction time of the sample having 0.53% of zinc stearate and 0.53% of zeolite was higher than those of the PVC plastigels having only zinc stearate or zeolite, the synergistic effect on thermal stability was observed at low levels of these additives.

Ammonium sorption by Gördes clinoptilolite rich mineral specimen

“…The isomorphic substitution of Si 4+ by Al 3+ causes a negative charge which is compensated by exchangeable cations such as Na . Due to its unique adsorption, cation exchange, catalytic, hydration and dehydration properties, clinoptilolite rich mineral specimen has been proposed for ammonium (Huang et al, 2010;Karapınar, 2009;Şenatalar and Sirkecioğlu, 1995;Ülkü, 1984) and heavy metal removal (Can et al, 2010;Motsi et al, 2009;Top and Ülkü, 2004), animal nutrition (Mumpton, 1999), gas adsorption (Armenta et al, 2003;Faghihian et al, 2008;Özkan and Ülkü, 2005), building and polymer industry (Atakul et al, 2005;Demir et al, 2008;Erdoğan et al, 2008;Savrık et al, 2010), as well as for biomedical applications (Pavelic et al, 2001(Pavelic et al, , 2002.…”

Stabilizing Effect of Biobased Additives on the Thermal Degradation of PVC

“…It can be seen that the dehydrochlorination curves can be divided into two sections: an initial low rate of HCl evolution followed by a more rapid dehydrochlorination after consumption of the stabilizers. The dehydrochlorination process was characterized in terms of induction time (period of time before incipient change in conductivity) [5], which also mean inhibition/retardation time. The dehydrochlorination characteristics in terms of inhibition/retardation time and the relative retardation index are given in Table 1.…”

“…Dehydrochlorination was monitored by conductivity measurement using the Thermomat 763 equipment. Detail description of the Thermomat equipment and its application in dehydrochlorination studies were given previously [5].…”

Effect of zinc soaps of rubber seed oil (RSO) and/or epoxidised rubber seed oil (ERSO) on the thermal stability of PVC plastigels

“…In a previous study [6], the measuring arrangement, experimental procedure and kinetic data obtained from conductivity measurements using the 763 PVC Thermomat have been discussed in detail. The rate of dehydrochlorination of PVC is determined by measuring the conductivity of the solution to which the evolved HCl gas is transferred.…”