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.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/90960 |
| Date | January 1986 |
| Creators | Scott, James Marvin |
| Contributors | Chemical Engineering |
| Publisher | Virginia Polytechnic Institute and State University |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Thesis, Text |
| Format | x, 124 leaves, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 15788178 |
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