Studies of polymer morphology with 13C inversion recovery cross polarization NMR

Dynamics of poly(vinyl butyral) studied using dielectric spectroscopy and 1H NMR relaxometry

“…15 13 C solid state NMR spectroscopy experiments highlighted the formation of regions with different polymer mobility in plasticized PVB and the dynamics of some functional groups could be qualitatively investigated at room temperature as a function of the plasticizer content. [16][17][18] All this considered, the dynamic properties of PVB remain largely unexplored.…”

Application of NMR cross‐polarization/modulus correlations to a series of polyurethane elastomers

“…Typical 90" pulse widths were 4.4 ps, the CP contact times were 1.5 ms, and the recycle delays were 3.0 s. Average cross-polarization time constants, ( TcH), were calculated as described previously.',2. 6 Dynamic mechanical analyses of the polyurethane samples were obtained utilizing a Polymer Laboratories dynamic mechanical thermal analyzer (DMTA) fitted with a low-temperature control unit. The sample sizes were approximately 2 X 5 X 50 mm.…”

“…If we make an assumption that 7, is equal to a + E, (6) If we then define a term, 0, as and plot D vs. E', such a plot should yield a straight line having a slope of c2 (which would be the proportionality constant between TcH and 7 , ) and an intercept of E,.…”

Molecular Correlations to Macroscopic Wood Performance Using CP/MAS NMR

“…For example, Schaefer et al (1977) successfully correlated the impact strength of several glassy polymers with the ratio of the cross-polarization (T CH ) and carbon rotating-frame relaxation (Ti p C) time constants. More recently it has been shown that crosspolarization measurements can be used to study the motional and morphological heterogeneities in solid polymers (Cory and Ritchey 1989;Parker et al 1989). With this technique, Parker et al (1990Parker et al ( , 1993 and Marcinko et al (1992Marcinko et al ( , 1994 have established a correlation between dynamic storage modulus (E') and the mean cross-polarization time constant, <T C H>, for a wide variety of synthetic polymers.…”

“…It is this motional effect that provides the correlation between <T C H> and the dynamic modulus in polymeric materials (Parker et al 1990). The biexponential behavior of protonated carbons can be described by the following equation (Parker et al 1989):…”