ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
In this paper experimentally determined values are reported for the thermal diffusivity (k) of various rubberlike polymers. Corresponding values of the thermal conductivity (W) can be computed from the well-known relationship, W = kpcp, where p and cp denote the density and specific heat at constant pressure of the composition. Measurements were made on (a) pure gum stocks prepared with natural rubber, Butyl (GR-I), Perbunan 18, Perbunan 26, Perbunan 35, Buna S (GR-S), polybutadiene, neoprene GN, polyisoprene, Silastic 160, and Silastic 180; (b) pure gum stocks of the first five rubbers listed under (a) containing in addition 20 parts of a hydrocarbon softener (Bardol), based on 100 parts by weight of the polymer; and (c) the Bardol stocks containing in addition 54 parts of carbon black (Kosmobile 66). From measurements of the rate of change of temperature within a rubber sphere suddenly subjected to a change in its surface temperature, it was found possible to determine the dependence of k on temperature. A satisfactory definition of the “mean” temperature of a sphere under these conditions is described. In a discussion of the effect of chemical composition and structure on heat conduction, the bearing of hindered rotation, cross linking and branching and interatomic bond strength on the results is pointed out. Values are derived for certain other properties of some of the polymers, including their characteristic Debye temperatures, specific heats at constant volume, flexibility of the main valence chains, compressibilities, and sound velocities.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1947.120020302
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