Determination of Orientational Order in Deformed Glassy PMMA from Solid-State NMR Data

Abstract

The orientational distribution function for polymer chain segments in plain-strain compressed glassy poly(methyl methacrylate) is evaluated, as a function of two polar angles, from a series of one-dimensional deuterium NMR spectra. The experimental data are analyzed using a tailored regulatory approach. For low degrees of orientational order, the choice of the regularization scheme is shown to become critical and two-dimensional Tikhonov-Phillips regularization yielded the best results for the present study.

Segmental orientation in plastically deformed glassy PMMA

“…6-8. Relative scatter of order parameters was estimated from simulated data by comparison with experimental NMR spectra as described in detail by Wendlandt et al (2005b) and yielded DD 2 00 =D 2 00 % 0:13 and DD 2 02 =D 2 02 % 0:17. In principal, an infinite number of order parameters could be calculated from an experimentally determined ODF.…”

“…In a previous study (Wendlandt et al, 2005b) a one-dimensional quadrupolar 1 H solidstate NMR experiment was described, which is sensitive to even low degrees of spatial orientation of deuterium-labeled chain segments in glassy PMMA. In Fig.…”

Structures and Unexpected Dynamic Properties of Phosphine Oxides Adsorbed on Silica Surfaces

“…[15] For averaging out a Pake pattern completely, an isotropic reorientation is needed. For example, 2 H MAS gives a Pake pattern for solid poly([D 3 ]methyl methacrylate) (PMMA), [16] although the CD 3 groups rotate rapidly around a C 3v axis. [6b] Similarly, solid ([D 1 ]Cp) 2 Fe gives a Pake pattern [9] despite fast Cp ring rotation, [6b] and also confined, but rotating benzene.…”

Numerical computation of relaxation spectra from mechanical measurements in biopolymers

“…The algorithms are available online and, in the present work, they will be denoted as Hansen (1994Hansen ( , 2002, Wendlandt (2005), Wendlandt, van Beek, Suter, and Meier (2005) and Marino (2007) following the names of the authors. The first two algorithms use Tikhonov's regularization with different approaches in their structure, whereas the third routine is a MATLAB implementation of the CONTIN algorithm (Provencher, 1982a(Provencher, , 1982b.…”