High-density polyethylene thermal degradation

W. Ding, J. Liang, and L.L. Anderson, Thermal and catalytic degradation of high-density polyethylene and commingled post-consumer plastic waste. Fuel Process. Technol., 51, 47 (1997). 

A. Garforth, S. Fiddy, Y. H. Lin, A. G. Siakhali, P. N. Sharratt, and J. Dwyer, Catalytic Degradation of High Density Polyethylene an Evaluation of Mesoporous and Microporous Catalysts using Thermal Analysis, Thermochim. Acta, 294, 65-69 (1997). 

S. Karagoz, J. Yanik, S. Ugar, M. Sa-lam and C. Song. Catalytic and thermal degradation of high-density polyethylene in vacuum gas oil over non-acidic and acidic catalysts. Applied Catalysis A General, 242, 51-62 (2003). 

There have been many reports on the thermal and catalytic degradation of high-density polyethylene (HDPE), as it is one of the main polymers in mnnicipal solid wastes [1]. 

N.S. Allen, A. Parkinson, F.F. Loffelman, and P.V. Susi, Photo-stabilizing action of a p-hydroxybenzoate compound in polyolefins. Part II. Thermal and photochemical behavior in high density polyethylene film, Polym. Degrad. Stab. 1984, 6, 65-79. 

Detrimental effects in WPC, 96 Thermal degradation, 95 Hemicellulosic materials, 77, 92, 94, 95, 180 Hemp fiber, 82, 83, 86, 101, 110 Cellulose content, 110 Eiber diameter, 110 Lignin cintent, 110 Specific gravity, 110 Heteropolysaccharides, 92 High density polyethylene (HDPE), 52, 55, 67, 68, 363, 371,... 

Though there are metals other than copper (such as iron, manganese and cobalt) that can accelerate thermal oxidation of polyolefins and related polymers such as EPDM, in practice, however, the inhibition of copper-catalyzed degradation of polyolefins is of paramount importance because of the steadily increasing use of polyolefin insulation over copper conductors. Among polyolefins, polyethylene is still the most common primary insulation material for wire and cable. In the United States, high-density polyethylene and ethylenepropylene copolymers are used in substantial amounts for communications wire insulation. 

Polyethylene (PE) waxes, i.e lov/ molecular weight poly-ethylenes, are useful materials in various applications PE waxes available on the market are usually polymers of 1000 to 10000 molecular weight obtained by telomerization, i e the polymerization of ethylene mder conditions able to assure only the formation of low-molecular-wei t polymers Some of these waxes are obtained by the thermal degradation of the usual-molecular-weight polyethylenes No information seems to be available about the use of waxes resulting as by-products in high-density polyethylene (HDPE) plants ... 

Figure 12.10 shows the release of volatiles during thermal degradation of polypropylene. Mica reinforces the polypropylene stability, while halogenated flame retardant reduces it. Both composite polymers are compared with the pure polymer. The thermal stability of low, medium and high-density polyethylenes has its linkage to the number of branches in the main polymer chain. It is of interest that the flammabihty expressed in the amount of oxygen consumed follows the similar tendency (Fig. 12.11). 

One early study of thermal degradation of polyethylene was carried out on low molecular weight polymers [453]. Later the work was repeated with high-density polyethylene [454]. The volatile products were identified by gas chromatogrq)hy. The biggest portiOTi of the volatiles was found to be propylene. 

Mukhopadhyay S, Srikanta R (2008) Thermal properties of high density polyethylene Composites with natural fibres coupling agent effect. Polym Degrad Stab 93 2048-2051... 

High-density polyethylene, Sholex 6050, may serve as an example. The materials were subjected both to thermal degradation and y-irradiation together with 2,4,6-tri-tert-butyl nitrosobenzene. As in the case of mechanical degradation of polymers in the presence of nitrosobenzene, ESR spectra from nitroxide radicals were observed... 

Rideal, G. R. and Padget, J. C, The thermal-mechanical degradation of high density polyethylene, J. Ptdym. Sri, Pofym. Sympos. Ed., 57,1-15 (1976). 

The thermal stability of high-density polyethylene and PE-HD/MDH composites is summarized in Table 4.4. High-density polyethylene degraded at a single step at temperature with maximal mass loss T ,=474.9 °C with remaining residue of about 0.1%. The thermal profile of PE-HD/MDFI composites was characterized by two main mass loss steps at temperature with maximal mass loss rate and... 

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