Abstract
We investigate the composition dependence of the segmental dynamics of poly(methyl methacrylate) [PMMA] in miscible binary blends with poly(ethylene oxide) [PEO] using quasi-elastic neutron scattering [QENS] in combination with deuterium labeling. Blends with 10, 20, and 30 wt % PEO are considered. Our main finding is that in all cases the segmental mobility of PMMA is controlled simply by the distance above the glass transition temperature. This holds for pure PMMA and all three blends and at all spatial scales over the 4−10 Å range of observation. The best fits to the chain connectivity model are obtained with a self-concentration of zero, indicating that the local “effective” concentration defined over length scales comparable to our experiment is equal to the bulk composition. This is again consistent with segmental dynamics that follow the bulk [mixture] composition. Within the temperature range measured, the relaxation times are consistent with Arrhenius behavior: the resulting activation energy is independent of composition and consistent with that obtained from dielectric spectroscopy for the merged αβ-process of pure PMMA.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
