Polyvinyl acetate pyrolysis

More recently, several studies on the pyrolysis of various adhesives either used or proposed for use as seam pastes in cigarette fabrication were conducted by Best (25A06, 25A07). He reported that, in contrast to a starch pyrolysate, the pyrolysate from polyvinyl acetate showed high levels of... 

These polymers possess rather low thermal stability. Thus, at temperatures above 190 °C polyvinyl acetate readily decomposes under vacuum to release acetic acid. The formation of acetic acid by a chain reaction which is initiated via the scission of the acetic acid molecule at the end of the polymer and the formation of a double bond leads to the formation of two main substances polyacetylene and acetic acid. However, the chain reaction leading to the formation of acetic acid may proceed via the cleavage of the ester bond. These bonds are less strong than the carbon - carbon bonds and, during pyrolysis of the polymer, should decompose first. Such cleavages of the ester bond should proceed randomly at any site in the polymer chain. The removal of the acetate radical is accompanied by the abstraction of an hydrogen atom from the neighbouring carbon atom to form acetic acid, and in this case the double bond appears in the polymer chain i.e., acetic acid is produced as a result of the intramolecular transformation ... 

Ethylene-vinyl acetate copolymers were investigated by simultaneous thermal analysis and pyrolysis gas chromatography. Both devices were coupled to a mass spectrometer. Calibration with polyvinyl acetate led to sufficient accuracy in relation to the vinyl acetate content, because of the linear calibration plot. Quantitative determination of vinyl acetate was carried out at both 500 and 700 C. The calibration plot was linear provided that the mass of vinyl acetate did not exceed a critical value. 18 refs. 

Thiolane 1,1-dioxide, known by the trivial name sulfolane, is obtained industrially by catalytic hydrogenation of 3-sulfolene. Sulfolane, colourless crystals, mp 27.5°C, bp 285°C, is water soluble. Sulfolane is a polar aprotic solvent and is used for the extraction of sulfur compounds from industrial gases and for the extraction of aromatic substances from pyrolysis fractions. It also serves as a solvent for cellulose acetate, polyvinyl chloride, polystyrene, and polyacrylonitrile. 

Computational Results Equilibrium thermochemical calculations (using STANJAN [35] and SOLGASMIX [36] codes) of a mixture of nonplastic and plastic surrogate solids were carried out under conditions of pyrolysis and combustion see Table 15.9. A large thermodynamic data file compiled from JANAF tables is used in these codes [37]. The nonplastic material is assumed to be cellulose while the plastic material may contain any or all of the following plastics polyethylene, polyvinyl chloride, polystyrene, polypropylene, polyethylene ter-aphathalic, nylon, latex in the form of rubber, polyurethane, and acetate. Cellulose represents the organic portion of the waste such as paper and cardboard. 

Products obtained by pyrolysis of other polymers is reviewed in Table 4.5. Some specific applications of the chromatography-MS technique to various types of polymers include the following PE [34,35], poly(l-octene) [29], poly(l-decene) [29], poly(l-dodecene) [29], CPE [36], polyolefins [37, 38], acrylic acid-methacrylic acid copolymers [39, 40], polyacrylate [41], nitrile rubber [42], natural rubbers [43, 44], chlorinated natural rubber [45, 46], polychloroprene [47], PVC [48-50], polysilicones [51, 52, 53], polycarbonates [54], styrene-isoprene copolymers [55], substituted olystyrene [56], PP carbonate [57], ethylene-vinyl acetate [58], Nylon 66 [59], polyisopropenyl cyclohexane-a-methyl styrene copolymers [60], cresol-novolac epoxy resins [61], polymeric flame retardants [62], poly(4-N-alkyl styrenes) [63], polyvinyl pyrrolidone [64], polybutyl-cyanoacrylate [65], polysulfides [66], poly(diethyl-2-methacryl-oxy) ethyl phosphate [67, 68], polyetherimide [69], bisphenol-A [70], polybutadiene [71], polyacenaphthalene [72], poly(l-lactide) [73], polyesterimide [74], polyphenylene triazine [75], poly-4-N-vinyl pyridine [76], diglycidylether-bisphenol-A epoxy resins [77], polyvinylidene chloride [78] and poly-p-chloromethyl styrene [79]. 

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