Alpha relaxation polyethylene

Babovich et al. [63] studied creep and stress relaxation of low-density polyethylene film cross-linked with beta radiation as a function of irradiation dose. They showed that both storage modulus and alpha relaxation were influenced by irradiation. Creep results showed an increase in the creep strain when the polymer was irradiated with a dose below 4 Mrad, in comparison with a nonirradiated low-density polyethylene. This increase corresponded to a disorientation in the amorphous phase, which took place as a result of the film heating during irradiation. 

Figure 10.12 Propagation of a localised smooth twist along the chain. As the twist starts ( ) it leaves behind it a translational mismatch. As the twist proceeds (2) the mismatch becomes attenuated at large distances from the twist by elastic distortion of the stem valence angles and bond length. (Reproduced with Mansfield, M. and Boyd, R.H. (1978) Molecular motions, the alpha-relaxation and chain transport in polyethylene crystals, /. Polymer Sci., Phys Ed., 16, 1227. Copyright (1978) John Wiley Sons, Ltd.)...

Mansfield, M. and Boyd, R.H. (1978) Molecular motions, alpha-relaxation and chain transport in polyethylene crystals. /. Polym. Sci. Phys. Ed., 16,1227. 

Popli R, Glotin M, Mandelkern L and Benson R S (1984) Dynamic mechanical studies of alpha-relaxation and beta-relaxation of polyethylene, J Polym Sci Polym Phys Ed 22 407-448. 

Alberola N, Cavaille J, Perez J. Mechanical spectrometry of alpha-relaxations of high-density polyethylene. J Polym Sci Part B Polym Phys 1990 28 569-86. 

Hoffman, J.D., Williams, G. and Passaglia, E. (1966) Analysis of alpha beta and gamma relaxations in polychlorotrifluoroethylene and polyethylene - dielectric and mechanical properties. /. Polym. Sci., C, 14, 173. 

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