ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Moments of the molecular weight distribution have been measured in the equilibrium ultracentrifuge under ideal conditions for two rough fractions of polyisobutylene (Mw 1.6 × 104 and 1.31 × 105). Flow and elastic recovery measurements were made on these materials and on a series of blends; the non-Newtonian flow at small shear stresses was characterized by the reciprocal of the Ferry “internal shear modulus,” Gi, and the magnitude of the elastic recovery by the steady-state elastic compliance, Je. This was found to be about two to three times the magnitude of 1/Gi. Measured values of Mz+1 for the fractions appeared unreasonably high compared to values obtained by assuming a Lansing-Kraemer distribution. With either set of values of Mz+1 for the fractions, it was found that Je was proportional to the square of (MzMz+1/Mw) for these materials, in disagreement with the results of molecular theories, which predict proportionality with the first power of this function.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1959.1203613019
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