Acoustic and relaxation behaviors of polydimethylsiloxane studied by using brillouin and dielectric spectroscopies

• Published in: Journal of the Korean Physical Society Vol. 68; no. 7; pp. 896 - 900
• Main Authors: Lee, Byoung Wan, Ko, Jae-Hyeon, Park, Jaehoon, Shin, Dong-Myeong, Hwang, Yoon-Hwae
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.04.2016; 한국물리학회
• Subjects: Mathematical and Computational Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Theoretical; 물리학; Relaxation process; Brillouin scattering; Dielectric; Elastic property; PDMS
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.68.896

The temperature dependences of the acoustic properties and the dielectric relaxation times of polydimethylsiloxane were investigated by using high-resolution Brillouin and broadband dielectric spectroscopies. The longitudinal sound velocity showed a large increase upon approaching the glass transition temperature while the acoustic absorption coefficient exhibited a maximum at ~263 K. Comparison of these results with previous ultrasonic data revealed a substantial frequency dispersion of the acoustic properties of this silicone-based elastomer. The relaxation times derived from the acoustic absorption peaks were consistent with the temperature dependence of the dielectric relaxation time of the structural a process, indicating a strong coupling between the acoustic waves and the segmental motions of the main chains.