Molecular glasses glass transition regime

Jamieson, A. M., Simha, R., Lee, H., Tribone, J., Laser-light scattering studies of bulk polymers in the glass-transition regime, in Structure and Mobility in Molecular and Atomic Glasses" Annals of the New York Academy of Sciences, 371, pp. 186-198 (1981). 

Fig. 1.2 Richness of dynamic modulus in a bulk polymer and its molecular origin. The associated length scales vary from the typical bond length ( A) at low temperatures to interchain distances ( 10 A) around the glass transition. In the plateau regime of the modulus typical scales involve distances between entanglements of the order of 50-100 A. In the flow regime the relevant length scale is determined by the proper chain dimensions...

The crystalline melting point and the glass transition temperature of a polymer, in themselves, provide a rough characterization of the polymer properties they also provide reference points for the various regimes within which the quantitative evaluation of properties must be made. How do Tjij and Tg depend on molecular structure ... 

The purpose of this paper is to discuss certain property sets from a uniBed point of view, which results in correlations between such sets. This point of view is based on a particular statisticd model of a molecularly disordered state. We start with the melt, proceed to the glass transition region, and thence to the glassy state. Here the concerns are boA the steady state and the relaxational regimes. 

Polymeric solids exhibit a wide spectrum of local molecular motion. In the classical subdivision into thermosets, rubbers and thermoplastics, both the thermosets and the thermoplastics below the glass transition temperature would exhibit transverse relaxation time on the sub-millisecond timescale, the so-called solid regime of NMR. It is these materials which require specialised solid state imaging methods rather than the elastomeric materials where... 

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