Optical configuration parameter

V. Galiatsatos, R.O. Neaffer, S. Sen and B.J. Sherman, Refractive index, stress optical coefficient, and optical configuration parameter of polymers. In J.E. Mark (Ed.), Physical Properties of Polymers Handbook, Springer-Verlag, New York, 1996, p. 535. 

RIS theory is used to predict values of the optical-configuration parameter Aa for ethylene - propylene copolymers as a function of chemical composition, chemical sequence distribution, and stereochemical structure of the propylene sequences. The calculations are based on information available for ethylene and propylene homopolymers, and on the model used to interpret the unperturbed dimensions of these copolymers. Values of Aa are generally found to decrease significantly with increase in the fraction of propene units, but to be relatively insensitive to chemical sequence distribution and stereochemical structure. Geometries and conformational energies are the same as those used for the interpretation of the unperturbed dimensions of these chains. The conformational energies used are E(q) = 0, EM 2.09, and E a>) = 0.37 kJ mol-1. 

Galiatsatos V, "Refractive Index, Stress-Optical Coefficient and Optical Configuration Parameters of Polymers", in Mark JE (Ed), "Physical Properties of Polymers Handbook", Springer-Verlag, 2nd Ed 2007. Chap. 50. 

Mean-square end-to-end distance Mean-square radius of gyration Mean-square dipole moment Mean-square optical anisotropy Optical configuration parameter... 

The relationship between the measured relative retardation (R) and the stress-induced birefringence (An) is given by R = fAn (2), in which t is the sample thickness. The stress optical coefficient C is defined by An = Ct (2), in which t is the true stress (t = f/A f is the force in newtons per square millimeter, and A is the cross-sectional area of the network sample). This coefficient is thus simply the slope of the line in a plot of An versus t. Finally, the optical configuration parameter An is defined by... 

Figure 3. Temperature dependence of optical configuration parameter for PDMS network containing 90.8 mol % short chains.

Refractive Index, Stress-Optical Coefficient, and Optical Configuration Parameter of... 

The stress-optical coefficient has units of mm /N. It is related to the optical configuration parameter, Aa, a cOTifig-uration-dependent property of a polymer, through... 

The optical configuration parameter may be calculated theoretically through the rotational isomeric state model. Its units are typically in cm. Stress-optical coefficient and optical configuration parameter data for polymers and copolymers can be found in Tables 50.3 and 50.4, respectively. In both tables wavelength is 6,328 A. The data in Tables 50.1-50.4 have been compiled from more than 100 references. For consistency the polymeric material names are reported exactly as in the original references. In some cases computer databases, given the material names listed here, may be able to provide structural information about the materials. 

TABLE 50.3. Optical configuration parameters (Aa) and stress-optical coefficients (C) of polymers. All values reported are at a ... 

Galiatsatos, V. Neaffer, R. O. Sen, S. Sherman, B. J., Refractive Index, Stress Optical Coefficient, and Optical Configuration Parameter of Polymers. In Physiccd Properties of Polymers Handbook, Mark, J. E., Ed. Springer-Verlag New York, 1996 pp 535-543. 

Pol5miers have many important optical properties, such as refractivity, reflection, scattering, absorption, clarity, haze, birefringence, stress—optical coefficient, optical configuration parameter, yellowness index, fight transmission, gloss, color, and surface texture among others (1). 

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