ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The thermodynamic theory of bulk ABA copolymers developed by Leary and Williams is extended to copolymer-solvent systems. Free energy expressions are derived for five hypothetical phase-separated morphologies and evaluated specifically for a polymer with approximately 25% of the A component. The separation temperature, Ts, at which a given morphology will be in equilibrium with a homogeneous mixture, is also evaluated. The major result is the prediction of the Ts(φS) depression, where φs is the solvent fraction. Depression is maximized when δS is equidistant between δA and δB, but becomes rapidly less when δS is outside the δA-δB range. Morphological favoritism is independent of φS and δS (model does not apply to preferential precipitation), with a planar microstructure being favored along with microstructures containing domains of B in continuous A for the 25% A polymer.
Additional Material:
13 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1977.180150906
