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Effects of mechanical and thermal stresses on electric degradation of polyolefins and related materials
Author(s) -
Mamedov Shaval,
Alekperov Vilayet,
Can Nursel,
Aras Faruk,
Yilmaz Gunes
Publication year - 2004
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200450833
Subject(s) - arrhenius equation , materials science , activation energy , low density polyethylene , electric field , composite material , polyethylene , degradation (telecommunications) , thermal , thermodynamics , chemistry , physics , electrical engineering , quantum mechanics , engineering
Degradation under the simultaneous effects of mechanical stress and temperature in polyolefins (PE, PP), composites on their basis (PE+PP fibre, PP+PP fibre, PP+glass fibre) and radiation low‐density polyethylene (X‐LDPE) used in high‐voltage cables obeys the thermofluctuation theory of Zhourkov (in certain σ and τ 0 intervals) based on the theory of Arrhenius is presented in the following form: τ σ = τ 0 exp[( U 0 − γσ )/ RT ] (1) where τ is durability. τ 0 is a constant (10 −12 ‐10 −13 s) equal to period of vibrations of atoms around equilibrium position, U 0 is the activation energy of the mechanical destruction process (at σ = 0), γ is a structure‐sensitive parameter, T is absolute temperature and R is universal gas constant. Electric degradation under the effects of electric field and temperature in the materials mentioned above obeys the equation: τ E = τ 0 exp[( W 0 − χE )/ RT ] (2) Here, τ E , W 0 and χ are analogous to τ σ , U 0 and γ , respectively. It is assumed that the following equation is valid under the simultaneous effects of E , σ and T : τ σ,E = τ 0 exp[( U 0 − ( γσ + χE ))/ RT ].(3) electric degradation