ISSN:
0449-2951
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Various self-diffusion and nuclear relaxation experiments are reported for a polyisobutylene of rather low molecular weight, in bulk and in solution. In the bulk, the self-diffusion coefficient obeys the Arrhenius relation, yielding an activation energy of 5.5 kcal./mole. In solution the activation energies are lower, approaching the value for the solvent at low concentration. The self-diffusion coefficient of the polymer at infinite dilution is 1.2 × 10-5 cm.2/sec. in CS2 and 0.44 × 10-5 cm.2/sec. in CCl4. The ratio is close to the inverse ratio of the solvent viscosities. Measurements of self-diffusion of the solvent have been made for cyclohexane in polyisobutylene. A simple interpretation of the data in terms of Stokes-Einstein models yields molecular dimensions which are too small by a factor of two or three.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1963.100010523
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