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Thermooxidative degradation polyethylene

The Course of Thermooxidative Degradation of LD- and HD- Polyethylene under Accelerated Testing Conditions... [Pg.45]

The extent of oxidative bond scissions in the insoluble R fractions (in analogy to polyethylene data (12)) may be concentrated in the noncrystalline isotactic PP chain segments (total initial crystallinity is about 50%, but increases presumably owing to secondary crystallization, particularly during thermooxidative degradation at 150°C). [Pg.119]

Afaunov V. V. Kozlov, G. V. Mashukov, N. 1. Zaikov, G. E. Fractal analysis of polyethylene inhibited thermooxidative degradation processes. Journal Apphed Chemistry, 2000, 73(1), 136-140. [Pg.303]

Stoehler et al. [44] studied the thermal properties of polyethylene-montmorillonite nanocomposites and found evidence for accelerated formation and decomposition of hydroperoxides during the thermooxidative degradation of the nanocomposites in the range of 170°C to 200°C, as compared to unfilled polyethylene, as weU as the formation of intermolecular chemical cross-links in the nanocomposites above 200°C due to recombination reactions involving the radical products of hydroperoxide decomposition. [Pg.156]

Related very much to practical considerations are the results of thermooxidation in the melt, or of immersion in boiling water, followed by extrusion, of pyrolysis in a fluidized bed reactor and of thermo-oxidation of an oriented film, whilst under stress. Depending upon the stress applied the rate of oxidation may either be increased, or decreased. A study has also been made of the effects of layer thickness, temperature, oxygen pressure, and antioxidants on the thermo-oxidative degradation of both polypropylene and polyethylene. The degradation mechanisms are discussed in detail. [Pg.382]

Pearce, E. M. et al. Fourier Transform IR Spectroscopy for the Study of Polymer Degradation, Thermal and Thermooxidative Degradation of Polyethylene Terephthalate, American Chemical Society (1983)... [Pg.1413]

Holmstrom, A. and Sorvik, E.M. (1978) Thermooxidative degradation of polyethylene. 1.. 2. Structural-changes occurring in low-density polyethylene, high-density polyethylene, and tetratetracontane heated in air, J. Polym. Sci., Polym. Chem. 16,2555-2586. [Pg.67]

During photo-oxidation, dicarboxylic acids were the class of products that clearly increased in the most severely degraded samples. As during thermooxidation, the most abundant of the dicarboxylic acids was butanedioic acid. Comparison between the number average molar mass and the relative amount of butanedioic acid, Fig. 6, showed a connection between the formation of butanedioic acid and the degree of degradation in the polyethylene matrix. However, the relative sum of all the carboxylic acids correlated even better with the number of chain scissions than the amoimt of only butanedioic acid. Fig. 7. [Pg.11]


See other pages where Thermooxidative degradation polyethylene is mentioned: [Pg.360]    [Pg.309]    [Pg.228]    [Pg.576]    [Pg.307]    [Pg.58]   
See also in sourсe #XX -- [ Pg.45 , Pg.46 , Pg.47 , Pg.48 , Pg.49 , Pg.50 , Pg.51 , Pg.52 , Pg.53 , Pg.54 , Pg.55 , Pg.56 , Pg.57 , Pg.58 , Pg.59 ]




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