| Résumé : |
An analysis of some of the shear adhesion data was attempted in an earlier study but could not completed due to some problems with the static shear test and its inability to measure high-sehar values. At that time, however, a strong correlation was noted between some of the log of the shear values obtained and the log of Mn.
The main problem with the static shear test is that adhesives based on S-I-S block copolymers have such high room temperature shear values, that only highly plasticized formulations can be evaluated in a convenient period of time.
Work by Adriane Moser at Virginia Tech under the direction of Prof. John Dillard has made some progress towards the development of a dynamic test that would still correlate with the static test. Unfortunately, this work is not yet complete and only the 15 percent oil compositions, A and C, could be evaluated here.
Shear adhesion values were evaluated in the same manner as the viscosity results. A Correlation between log shear and log Mn,was still noted but, it was no longer particularly strong. Also, no significant correlation was observed between log shear and any of the variables relating to compatibility or aromatic content. A good model for the characterisation of shear adhesion will have to await further development. |
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Under the microscope in ADHESIVES AGE, Vol. 42, N° 10 (10/1999)
