Polyethylene thermal

Fiber glass provides effective inhibition of polyethylene thermal destruction up to 400°C. The inhibitive efficiency increases with increased content of sodium oxide from 0.7-16% (Table 5). 

Table 5 Inhibition of Polyethylene Thermal Destruction by Filler—Fiberglass of Varying Alkalinity...

At the first stage of polyethylene thermal destruction the metallizing of polyethylene macroradical by the metal radical takes place. 

Boric acid esters provide for thermal stabilization of low-pressure polyethylene to a variable degree (Table 7). The difference in efficiency derives from the nature of polyester. Boric acid esters of aliphatic diols and triols are less efficient than the aromatic ones. Among polyesters of aromatic diols and triols, polyesters of boric acid and pyrocatechol exhibit the highest efficiency. Boric acid polyesters provide inhibition of polyethylene thermal destruction following the radical-chain mechanism, are unsuitable for inhibition of polystyrene depolymerization following the molecular pattern and have little effect as inhibitors of polypropylene thermal destruction following the hydrogen-transfer mechanism. 

Inhibition of polyethylene thermal destruction by polypyrocatechin borate could be represented as follows. The initial molecular-chain scission of branched... 

The effect of thermal aging on polyethylene and isotactic polypropylene have been studied by Konar et al. [49]. They used contact angle, contact angle hysteresis, and XPS to characterize the modified surfaces of the polymers. Hysteresis increased with aging temperature. In the case of polyethylene, thermal aging led to a significant increase in adhesion strength of polyethylene with aluminium, but the increase in the case of polypropylene was much less marked. 

Fourier transform NMR spectroscopy, polyethylene thermal oxidation, 695 Fourier transform-Raman spectroscopy hydroperoxides, 692 nitrile hydrolysis, 702 see also Raman spectroscopy Four-memhered peroxides, 164, 1212-13 FOX (Xylenol Orange-ferric complex) assay hydrogen peroxide determination, 628, 632, 657, 658... 

The study of polyethylene thermal decomposition is important in relation to the polymer resistance to heating [2], to various attempts to use waste containing polyethylene as a combustible or as a source of other useful materials [3-7], or to environmental issues when polyethylene is burned [8]. Various other studies on polyethylene pyrolysis were reported [9-22], etc. 

Keywords Catalysis intercalation polymerization kinetics layered clay nanocomposite oxidation polyethylene thermal degradation... 

Although the general outlines of polyethylene thermal oxidation with molecular oxygen are understood generally, traditional investigative methods have left some questions unanswered. The exact nature of the oxidation products is not completely clear (10,11,12,13). This is caused by heavy reliance on ir spectroscopy. IR spectroscopy suffers from band overlap, particularly in the important carbonyl stretch region near 1725 cm"1, and from the necessity of establishing reliable extinction coefficients. 

Figure 3 Changes in the fractions of gases, oils and wax produced from tion of polyethylene thermal decomposition products over a silica-alumina catalysts correlate with the Brensted acidity ...

Figure 9.2 shows the volume versus temperature for polyethylene. Thermal expansion coefficients are derived from the slopes of such plots by using... 

Bocchini S, Frache A, Camino G, Claes M. Polyethylene thermal oxidative stabilisation in carbon nanotubes based nanocomposites. Eur Polym J 2007 43 3222-3235. 

E. Richaud. Kinetic modelling of phenols consumption during polyethylene thermal oxidation. European Polymer Journal 49(8), 2223-2232, August 2013. 

X. Colin, B. Fayolle, L. Audouin, J. Verdu. About a quasi-universal character of unstabilised polyethylene thermal oxidation kinetics. Polymer Degradation and Stability 80(1), 67-74, (2003). 

Derivatives of polyisobutylene (6. in Figure 9.1) offer the advantage of control over the molecular weight of the polyisobutylene obtained by cationic polymerization of isobutylene. Condensation on maleic anhydride can be done directly either by thermal activation ( ene-synthesis reaction) (2.1), or by chlorinated polyisobutylene intermediates (2.2). The condensation of the PIBSA on polyethylene polyamines leads to succinimides. Note that one can obtain mono- or disuccinimides. The mono-succinimides are used as... 

Phosphoms-containing additives can act in some cases by catalyzing thermal breakdown of the polymer melt, reducing viscosity and favoring the flow or drip of molten polymer from the combustion zone (25). On the other hand, red phosphoms [7723-14-0] has been shown to retard the nonoxidative pyrolysis of polyethylene (a radical scission). For that reason, the scavenging of radicals in the condensed phase has been proposed as one of several modes of action of red phosphoms (26). 

A variety of cellular plastics exists for use as thermal iasulation as basic materials and products, or as thermal iasulation systems ia combination with other materials (see Foamed plastics). Polystyrenes, polyisocyanurates (which include polyurethanes), and phenoHcs are most commonly available for general use, however, there is increasing use of other types including polyethylenes, polyimides, melamines, and poly(vinyl chlorides) for specific appHcations. 

About 35% of total U.S. LPG consumption is as chemical feedstock for petrochemicals and polymer iatermediates. The manufacture of polyethylene, polypropylene, and poly(vinyl chloride) requires huge volumes of ethylene (qv) and propylene which, ia the United States, are produced by thermal cracking/dehydrogenation of propane, butane, and ethane (see Olefin polymers Vinyl polymers). 

Organic peroxides are used in the polymer industry as thermal sources of free radicals. They are used primarily to initiate the polymerisation and copolymerisation of vinyl and diene monomers, eg, ethylene, vinyl chloride, styrene, acryUc acid and esters, methacrylic acid and esters, vinyl acetate, acrylonitrile, and butadiene (see Initiators). They ate also used to cute or cross-link resins, eg, unsaturated polyester—styrene blends, thermoplastics such as polyethylene, elastomers such as ethylene—propylene copolymers and terpolymers and ethylene—vinyl acetate copolymer, and mbbets such as siUcone mbbet and styrene-butadiene mbbet. 

SolubiHty parameters of 19.3, 16.2, and 16.2 (f /cm ) (7.9 (cal/cm ) ) have been determined for polyoxetane, po1y(3,3-dimethyl oxetane), and poly(3,3-diethyloxetane), respectively, by measuring solution viscosities (302). Heat capacities have been determined for POX and compared to those of other polyethers and polyethylene (303,304). The thermal decomposition behavior of poly[3,3-bis(ethoxymethyl)oxetane] has been examined (305). 

Sihcone products dominate the pressure-sensitive adhesive release paper market, but other materials such as Quilon (E.I. du Pont de Nemours Co., Inc.), a Werner-type chromium complex, stearato chromic chloride [12768-56-8] are also used. Various base papers are used, including polyethylene-coated kraft as well as polymer substrates such as polyethylene or polyester film. Sihcone coatings that cross-link to form a film and also bond to the cellulose are used in various forms, such as solvent and solventless dispersions and emulsions. Technical requirements for the coated papers include good release, no contamination of the adhesive being protected, no blocking in roUs, good solvent holdout with respect to adhesives appHed from solvent, and good thermal and dimensional stabiUty (see Silicon COMPOUNDS, silicones). 

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