Thermal stabilisation of poly(vinyl chloride) by organotin compounds

Abstract

The effect of LSN 117 (dioctyl tin bis isooctyl thioglycollate, an organotin compound) on the heat stability of plasticised PVC was investigated in this study. The organotin stabiliser had carbonyl and carboxylate groups and PVC contained traces of Fe, Zn, Ca, Cu and Sn. The heat stability of the films were tested at 140 C and 160 C or 180 C by heating in an air circulation oven up to 2 h and by measuring HCl evolved using a Metrohm 763 PVC thermomat and by thermogravimetric analysis. The onset of HCl evolution was at 14.3 and 2.5 h at 140 C and 160 C, respectively, for PVC film without LSN117. On the other hand, the film with LSN117 did not evolve HCl in 30.3 h at 140 C. HCl started to evolve from the films with LSN 117 in 14.3 h at 160 C. The TGA curve also indicated PVC film with LSN 117 degraded at higher temperatures than control films. LSN 117 was found to be a good heat stabiliser for plasticised PVC and it did not have any detrimental effect on mechanical properties.

Additives effects on the shrinkage behavior of PVC sheets

“…3,[6][7][8][9][10] Nevertheless, thermal degradation of PVC is one of the inherent problems associated with the manufacture and use of some polymers. 11 These problems can be minimized by introducing stabilizing additives, which generally contain heavy metals such as cadmium and lead, organotin compounds, 12 phosphites, 13 and calcium and zinc salts. 14,15 But it is shown that the latter ones have less toxicity and so they can be used as heat stabilizers in most applications, especially food packaging and medical devices.…”

Degradação biológica do PVC em aterro sanitário e avaliação microbiológica

“…O desenvolvimento da coloração na superfície das amostras foi atribuído ao conjunto de duplas ligações conjugadas, formadas no processo de degradação térmica (desidrocloração) [53] e as sequências de polienos podem conferir a coloração indesejada ao polímero [54] . As alterações na coloração dos filmes também são atribuídas à colonização dos microrganismos, pela excreção de pigmentos microbiais lipofílicos, caracterizando o processo de biodegradação do polímero [32] .…”

Effect of thermal stabilizers composed of zinc barbiturate and calcium stearate for rigid poly(vinyl chloride)

“…The thermal stability of prepared PVC films was determined by the following two methods: thermomat described in detail elsewhere [5,24]. 0.50 g of PVC film cut into about 2.0 mm  2.0 mm size was placed in the reaction vessel.…”

“…(5). ZnSt 2 as the product from such a reaction is another effective thermal stabilizer for PVC, and the other product CaCl 2 does not promote a sudden "zipper dehydrochlorination" as ZnCl 2 does [10].…”