Segmental Dynamics of Poly(methyl Acrylate)-d₃ Adsorbed on Anopore: A Deuterium NMR Study
The segmental dynamics of poly(methyl acrylate-d3) (PMA-d3) adsorbed in the pores of anopore membranes has been investigated using deuterium NMR over the temperature range 25-80 C. The onset of the NMR glass-transition temperature (Tg) for the adsorbed samples was approximately 15 C higher than that for the bulk sample. The adsorbed polymer contained segments with restricted mobility (glassy), even at the highest temperatures studied, at which the bulk polymer showed only mobile segments. The spectra from samples with different adsorbed amounts of PMA-d3, between 1.1 and 4.2 mg/m2, were similar in their temperature-dependent mobilities. Neither was there much difference in the spectra of PMA-d3 on anopore samples with pore sizes of 0.2 and 0.02 m. However, for a solvent-washed sample with an adsorbed amount of 0.7 mg/m2, additional restriction in PMA-d3 mobility was observed.
M. O. Okuom et al., "Segmental Dynamics of Poly(methyl Acrylate)-d₃ Adsorbed on Anopore: A Deuterium NMR Study," Langmuir, American Chemical Society (ACS), Feb 2008.
The definitive version is available at http://dx.doi.org/10.1021/la703103j
National Science Foundation (U.S.)
Keywords and Phrases
Deuterium; Glass transition temperature; Nuclear magnetic resonance
Article - Journal
© 2008 American Chemical Society (ACS), All rights reserved.