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An experimentally disigned melt rheological characterization of starblock polymers

The melt rheological behavior of structurally defined starblock polymers was investigated using the experimental design technique of response surface methodology. A rotatable central composite design (ccd) was employed with linear 2⁵ factorial structure and with axial points to fit the pure quadratic terms. Regression analysis of rheological data from styrene-isoprene and t-butyl styrene-isoprene starblock polymers was used to generate four models whose terms have a p-value ≤ 0.1. The fitted models of viscosity and elasticity were a function of temperature, weight percent uncombined diblock, frequency, casting solvent, and annealing time.

Changes in melt behavior were hypothesized to be dependent on mechanisms related to phase separation and/or architecture. The modeled behavior verified the proposed mechanisms enabling a generalization of the results to the melt behavior of block polymer systems. The guidelines for the applicability of the well known Cox-Mertz relation and WLF superposition technique, as well as the transition to the Forced High Elasticity State, are discussed in terms of melt connectivity and elasticity. / M.S.

Identiferoai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/90960
Date January 1986
CreatorsScott, James Marvin
ContributorsChemical Engineering
PublisherVirginia Polytechnic Institute and State University
Source SetsVirginia Tech Theses and Dissertation
Languageen_US
Detected LanguageEnglish
TypeThesis, Text
Formatx, 124 leaves, application/pdf, application/pdf
RightsIn Copyright, http://rightsstatements.org/vocab/InC/1.0/
RelationOCLC# 15788178

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