On the thermal treatment of plastic mixtures of MSW: Pyrolysis kinetics

This paper presents an overview of the recent literature on flame retardancy of poly(vinyl chloride) (PVC). A short overview of mechanisms of thermal decomposition of PVC, especially those which lead to char formation, isalso presented because this gives insight into the mechanisms of flame retardant action. New developments in the area are mostly focused on combinations of various flame retardants and smoke suppressants in the search for synergistic effects. Because different additives show different mechanisms of action, synergistic combinations are very probable. New developments in phosphate ester plasticizers are reported in the literature.

Overview of the recent literature on flame retardancy and smoke suppression in PVC

Autocatalysis during the thermal dehydrochlorination of poly(vinyl chloride) (PVC) is shown to be a free-radical process that converts the ordinary monomer units of the polymer into chloroallylic structures that have low thermal stabilities. In the first stage of dehydrochlorination, conjugated polyene sequences are created by a nonfree-radical route. They react with HCl to give cation monoradicals and/or excited cation diradicals. One or both of these species, or other radicals formed from them, can then abstract methylene hydrogen in order to produce new radicals that are also carbon-centered. These are converted by chlorine-atom β scission into the chloroallylic segments, which start the growth of new polyenes in the usual (nonradical) way. At 180 °C in solid PVC, autocatalysis was inhibited by free-radical scavengers (a hindered phenol, triphenylmethane, and metallic mercury) but greatly enhanced by an increased concentration of HCl when all-trans-β-carotene, a model for PVC polyene sequences, was int...

Mechanism of Autocatalysis in the thermal dehydrochlorination of poly(vinyl chloride)

Pyrolysis or combustion of plastics are of interest from different points of view: on the one hand polymers from which harmful substances may arise are involved in fires or are fed to incinerators; on the other hand plastic refuses are an alternative resource of energy or chemical raw materials. For designing recycling procedures the behaviour of the decomposition of polymers with regard to the decomposition products and the kinetics of decomposition must be known. Plastic refuses encompass chlorine- and/or nitrogen-containing polymers which may form toxic or corrosive products under pyrolytic conditions or in combustion. These components must be separated before processing or the troublesome elements have to be eliminated by pretreatment. The aim of this work was to investigate the kinetics of pyrolysis of polyfvinyl chloride) and mixtures of poly(vinyl chloride) with polyethylene, polypropylene, polystyrene and polyamide 6. By means of simultaneous thermogravimetry-mass spectrometry the kinetic...

Investigation of the Kinetics of Pyrolysis of PVC by TG-MS-Analysis

Stabilization of PVC by epoxidized sunflower oil in the presence of zinc and calcium stearates

Thermal dehydrochlorination and stabilization of poly(vinyl chloride) in solution: Part V. Influence of structural defects in the polymer

Polaron mechanism in the thermal degradation of poly(vinyl chloride)

Thermal dehydrochlorination and stabilization of poly(vinylchloride) in solution: Part IV—Synergistic effects of β-diketone compounds and metal soap stabilizers

Hoang Tran Van

Papers

Thermal dehydrochlorination and stabilization of poly(vinyl chloride) in solution: Part V. Influence of structural defects in the polymer

Polaron mechanism in the thermal degradation of poly(vinyl chloride)

Thermal dehydrochlorination and stabilization of poly(vinylchloride) in solution: Part IV—Synergistic effects of β-diketone compounds and metal soap stabilizers