Spin label study of phase morphology and polymer segmental motion in poly(acrylic acid)–poly(ethylene oxide) complex

✍ Scribed by Li Tan; Guangqiang Lu; Shiming Chen; Zhenghua Ping; Yimin Shen

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 119 KB
• Volume: 41
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1276

✦ Synopsis

Abstract

The ESR lineshapes of nitroxide radical end‐labeled on poly(ethylene oxide) (SLPEO) for the pure polymer and for different weight ratio complexes with poly(acrylic acid) (PAA) were studied as a function of temperature. For SLPEO one spectral component was detected in the entire temperature range, indicating that the spin label was in the homogeneous phase domain. For all PAA–PEO complexes two spectral components with different rates of motion, a ‘fast’ and a ‘slow’ component, were observed, which indicates the existence of microheterogeneity at the molecular level: the more mobile the PEO‐rich microphase, the more rigid is the PAA‐rich microphase. On the other hand, the SLPEO polymer segmental motion was restricted owing to the hydrogen bond interaction between the carboxyl proton in PAA and the ether oxygen in PEO. This restriction was exacerbated with increasing the PAA content in the complex, which could be further substantiated through the calculated S and τ~c~ values. Copyright © 2003 John Wiley & Sons, Ltd.