Automatic equipment for studying the processes of low-temperature dehydrochlorination of chlorine-containing polymers

Nepochatykh, O.V.; Абдуллин, М. И.; Минскер, К. С.; Zaikov, G.Ye.; Jonge, C. R. H. I. De

doi:10.1016/0141-3910(87)90021-8

Cited by 2 publications

(1 citation statement)

References 2 publications

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“…The temperature was chosen because it was thought to be one at which it is possible to speculate that products could be exposed, when standing in a hot climate. Moreover, it is essential to recall that it has been shown that the Arrhenius parameters for the rate of dehydrochlorination of PVC are very different at temperatures above and below 858C (which may be associated with the glass transition temperature [16]). In fact, the activation energy at the lower temperatures is over twice as high as that at the higher temperatures.…”

Section: Discussionmentioning

confidence: 99%

Hydrogen chloride evolution from the heating of poly(vinyl chloride) compounds

Hirschler¹

2005

Fire and Materials

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SUMMARYThe dehydrochlorination and the thermal decomposition of five PVC materials was studied using two techniques: a batch analytical method, combining ion chromatography and atomic absorption and continuous thermogravimetry. The temperatures studied ranged from 608C to 1208C, over a period of almost one year (50 weeks). It was found that a very large proportion of the soluble chloride emitted early on by the PVC materials into the liquid phase is not hydrogen chloride. None of the five materials tested emitted significant amounts of HCl at temperatures lower than 1058C. The emissions at 908C after 50 weeks ranged from 50.01 Fg/g to 23.62 Fg/g. Furthermore, one of the materials tested emitted virtually no HCl, even at 1058C, as the amount of HCl measured was almost indistinguishable from the normal background of the analytical instruments (37.30 Fg/g after 50 weeks).Numerical calculations of kinetic reaction rates and extrapolation of the results to use temperatures (408C) indicate that properly stabilized PVC compounds will be unlikely to lose 1% of the mass of PVC as HCl until 2 billion years have passed. This number has no physical meaning as such and may be incorrect by a vast margin, but it clearly indicates that a 1% loss of HCl is unlikely to occur during the useful lifetime of a commercial product into which the PVC material has been fabricated. This is a conservative estimate, which ignores the much higher activation energy for dehydrochlorination at temperatures below the glass transition temperature (ca. 858C).

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Section: Discussionmentioning

confidence: 99%

Hydrogen chloride evolution from the heating of poly(vinyl chloride) compounds

Hirschler¹

2005

Fire and Materials

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Multilayer method as a tool for depth dependent polymer film photodegradation studies

Nepotchatykh¹,

Power²

2000

Polymer Engineering & Sci

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A new polymer film destructive depth profiling protocol is presented for the analysis of photo‐ and thermally degraded thin films on the depth scale of less than 100 microns. The method, demonstrated here on thin films of poly(vinyl chloride) (PVC), provides a means of preparation of thin laminates of high optical quality comprised of many (>20) thin layers of individual thickness less than 15 microns. The constituent layers are fused together under appropriate pressure, temperature and time treatment to yield a film assembly of high optical quality that behaves like a uniform single layer during photodegradation exposure, but which may still be separated after treatment. Compared to previous techniques, this new method is relatively simple and non‐labor intensive. Film adhesive properties are controlled to within ± 5% Concentration depth profiles of polymer photolysis products were reconstructed by analyzing each of the separated layers using UV‐visible spectrophotometry. The continuity of these film assemblies with respect to mechanical properties, adhesive properties and the depth distribution of key photolysis reagents and products was confirmed using photothermal and reference microscopy techniques. Optical absorption depth profiles examined in UV‐ photodegraded poly(vinyl chloride) (PVC) films exhibited the classic dependencies expected in the presence of nitrogen and oxygen atmospheres.

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Automatic equipment for studying the processes of low-temperature dehydrochlorination of chlorine-containing polymers

Cited by 2 publications

References 2 publications

Hydrogen chloride evolution from the heating of poly(vinyl chloride) compounds

Hydrogen chloride evolution from the heating of poly(vinyl chloride) compounds

Multilayer method as a tool for depth dependent polymer film photodegradation studies

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