Abstract
Random chain scission constants have been determined for the photolysis of polyisobutylene in n-alkane solutions. These rate constants are diffusion controlled since they are due to chain radicals escaping from medium cages. Plots of these rate constants vs. 1/η (where η is the solvent viscosity) and plots of the rate constants vs. Mn−3/2 and Mn−1/2, respectively, give straight lines. Discussion shows that the case of translational diffusion for kexp as a function of 1/η and 1/Mn1/2 is the one which gives the most reasonable results. About 103 scissions are mended for each permanent chain scission undergone by the polymer. It is suggested that about 24 Å separation of radicals (i.e., 4 times the radius of one solvent molecule) by translational diffusion are sufficient for effecting a permanent chain scission. A translation of ca. 370 Å, as required by the case where kexp is a function of Mn−3/2, seems to be unrealistic.
Similar content being viewed by others
Article PDF
References
S. W. Benson and A. M. North, J. Am. Chem. Soc., 84, 935 (1962).
H. H. G. Jellinek and M. D. Luh, Eur. Polym. J., Supplement, 1969, pp 149—171.
(See also J. J. Lichorat, Ph.D. Thesis, Clarkson College, Potsdam, N.Y., 1977.)
P. Carstensen and B. Rånby, “Radiation Research,” North Holland Publ. Co., Amsterdam, 1967, p 297.
J. Brandrup and E. H. Immergut, “Polymer Handbook,” 2nd ed, John Wiley & Sons, New York, N.Y., 1975.
J. Durup, J. Chim. Phys., 51, 64 (1954).
M. v. Smoluchowski, Z. Phys. Chem., 92, 129 (1918).
A. Einstein, Ann. Phys., 17, 549 (1905).
A. M. North, “The Collision Theory of Chemical Reaction in Liquid,” Methuen and Co. Ltd., London, 1964.
K. Horie and I. Mita, Polym. J., 9, 201 (1977).
H. K. Mahabadi and K. F. O’Driscoll, J. Polym. Sci., Polym. Chem. Ed., 15, 283 (1977).
K. Horie and I. Mita, Polym. J., 4, 341 (1973).
G. Beck, D. Lindenau, and W. Schnabel, Eur. Polym. J., 11, 761 (1975).
(See also W. Schnabel, in “Aspects of Degradation and Stabilization of Polymers,” H. H. G. Jellinek, Ed., Elsevier Scientific Publ. Co., New York, N.Y., 1978, Chapter 4, p 184.)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Jellinek, H., Lichorat, J. Recombination of Random Chain Scissions of Polyisobutylene in n-Alkane Solutions. Polym J 12, 347–353 (1980). https://doi.org/10.1295/polymj.12.347
Issue Date:
DOI: https://doi.org/10.1295/polymj.12.347