Specific heat stretch dependence

Local temperature increases resulting from light absorption contribute to the shrinkage of this stretched rubber, similar to that observed in the contraction behavior of swollen gels with azobenzene chromophores, as described earlier. Such an effect could result from insufficient heat exchange in the solid polymer sample and be dependent on the specific heat capacity and the density of the polymer. The experimental difficulty in measuring simultaneously in situ temperature increases in the rubber and contraction under irradiation leaves an uncertainty in the interpretation of the photocon-... 

Specific volume v J, thermal expansion coefficient, heat capacity at constant pressure (cj, heat capacity at constant volume (cj, enthalpy, entropy, and thermal conductivity (X) are thermal characteristics relevant for processing and applications. They depend on PE grade, temperature, pressure, average molecular weight, branching, crystallinity or density, stretching ratio, heating rate, spherulite size, and so on. 

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