Papers Published

  1. Hill, A. J. and Jones, P. L. and Lind, J. H. and Pearsall, G. W., POSITRON ANNIHILATION LIFETIME STUDY OF ISOTHERMAL STRUCTURAL RELAXATION IN BISPHENOL-A POLYCARBONATE., Journal of Polymer Science, Part A: Polymer Chemistry, vol. 26 no. 6 (1988), pp. 1541 - 1552 [pola.1988.080260605] .
    (last updated on 2007/04/10)

    Abstract:
    Positron annihilation lifetime spectroscopy has been used to study the isothermal relaxation response of compression molded bisphenol-A polycarbonate at temperatures of 263, 273, and 303 K. The temperature dependence of both the lifetime and intensity of the ortho-Positronium (o-Ps) pickoff component is discussed in terms of ductile-to-brittle transition behavior and free volume theory. An additive exponential model and the Williams-Watt model were used to analyze the relaxation as a function of temperature and provided results consistent with the anticipated molecular mobility of polycarbonate at sub-T//g temperatures.

    Keywords:
    POLYMERS - Glass Transition;