Dielectric spectroscopy of diglycidyl ether of bisphenol-A at glass transition temperature

• 作者: Soheil Sharifi
• 来源期刊: 自然科学期刊(英文)
• 学科: 化学
• 关键词: DIELECTRIC RELAXATION NANO-SIZE MOTION SECONDARY RELAXATION PRESSURE and Temperature
• 年，卷（期）: zrkxqkyw,（2）
• 页码范围: 136-141
• 页数: 6页
• 分类号: O6

摘要

We used broadband dielectric spectroscopy in the frequency range from 10–2 Hz up to 107 Hz and we found dynamics of the primary α- and intermolecular Johari-Goldstein (JG) β-processes are strongly correlated in diglycidyl ether of bisphenol-A over a wide temperature from 193 to 283K and pressure P range from 0.1 to 600 MPa. Analysing the temperature and pressure behavior of the α - and (JG) β-processes, a clear correlation has been found between the structural relaxation time, the Johari-Goldstein relaxation time and the dispersion of the structural relaxation. These results support the idea that the Johari-Goldstein relaxation acts as a precursor of the structural relaxation and therefore of the glass transition phenomenon.