Narayanaswamy theory

R. NarayanaswamI and Howard M. Adelman, Evaluation of the Tensor Polynomial and Hoffman Strength Theories for Composite Materiais, Journal of Composite Materials, October 1977, pp. 366-377. 

One theory that describes the temperature dependence of relaxation time and structural recovery is the Tool-Narayanaswamy-Moynihan (TNM) model developed to describe the often nonlinear relationship between heating rate and Tg. In this model, the structural relaxation time, x, is referenced as a function of temperature (T), activation enthalpy (Ah ), universal gas constant (R), hctive temperature (7)), and nonlinearity factor (x) (Tool, 1946 Narayanaswamy, 1971 Moynihan et al., 1976) ... 

Although use of the Narayanaswamy equation is successful in the predictions of the data in Figs. 4-18 and 4-19, for polymeric liquids it fails badly and should be replaced by the Adam-Gibbs equation (Matsuoka 1992). For additional discussion of phenomenological theories of nonlinear relaxation, see Scherer (1992) and McKenna (1989, 1994),... 

Guthrie, A.J., Narayanaswamy, R. and Russell, D.A. (1988). Application of Kubelka-Munk diffuse reflectance theory to optical fibre sensors. Analyst 113,457-461. Narayanan, S. (1989). Principles and Applications of Laboratory Instrumentation. ASCP Press, Chicago, pp. 192-195. 

Tool-Narayanaswamy-Moynihan (model of kinetics of the glass transition) [Tool, 1946a,b Narayanaswamy, 1971 Moynihan et al., 1976] two-parameter theory... 

From the above discussion one can see that the kinetics of glasses exhibit a rich variety of behaviors which offer a severe test of any model. Until the development by Narayanaswamy in 1971 of a mathematical formalism analogous to that of reduced variables used in viscoelasticity theories, there was no model which incorporated all of the ingredients necessary to explain the major features of the phenomenology described in the previous section. 

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