Synthesis and physical properties of styrene-vinylpyridinium ionomers of various architectures

• Main Author: Gauthier, Sylvie, 1955-
• Format: Others
• Language: en
• Published: McGill University 1985
• Subjects: Ionomers.; Polymers > Mechanical properties.; Polymers > Thermal properties.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72029

Styrene-4-vinylpyridinium ionomers of different architectures, random and ABA blocks, were synthesized and their thermal and dynamic mechanical properties investigated. === The Tg's of the random ionomers were found to increase regularly with increasing ion content, at a rate of about 3.5(DEGREES)C per mole % of ions. In contrast with other ionomeric systems studied before, however, these materials showed only one peak in their tan delta curves, associated with the Tg of the matrix. The absence of a second, high temperature peak suggests the absence of clusters in these vinylpyridinium ionomers, at least at temperatures above their Tg. The storage modulus curves were in agreement with this conclusion. === An elaborate polymerization line was constructed for the production of the block copolymers by living anionic polymerization; a basic design was modified considerably and two new units were completely designed in this laboratory. Only one Tg, associated with the Tg of the polystyrene phase, was observed in DSC measurements for the resulting ionomers. The glass transition of the ionic domains was detected in dynamic mechanical measurements as a shoulder on the low temperature side of the polystyrene transition. This unexpected low value for the Tg of the ionic domains was attributed to plasticization by water.