Influence of the molecular structure on the dynamics in poly(ester-imide)s

✍ Scribed by Merenga Abdallah; Herbert Groothues; Friedrich Kremer; Hans R. Kricheldorf

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 337 KB
• Volume: 198
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1997.021980912

✦ Synopsis

Abstract

Dielectric spectroscopy in the frequency range from 0.1 to 10^5^ Hz was employed to study the molecular dynamics of main‐chain poly(ester‐imide)s (PEIMs) with varying spacer lengths from 5 to 12 methylene units. For all samples three relaxation processes were observed. The β‐process shows an Arrhenius‐like temperature dependence with activation energies between 50 and 55 kJ/mol. This process is assigned to a local libration of the ester groups. The α^*^‐process shows a WFL‐like temperature dependence. It is assigned to a main‐chain‐coupled motion of the mesogens around their short molecular axes. The α‐process also follows a WFL‐like temperature dependence. It is assigned to cooperative main‐chain motion of PEIM and it is correlated to the glass transition.