Selective plasticization of the ionic domains in a segmented thermoplastic ionene cationomer

Authors

  • L. N. Venkateshwaran,

    1. Department of Chemical Engineering and Polymer Materials & Interfaces Laboratory, Virginia Polytechnic Institute & State University, Blacksburg, Virginia 24061
    Current affiliation:
    1. Amoco Chemical Company, Amoco Research Center, P.O. Box 3011, Naperville, IL 60566
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  • C. E. Leir,

    1. Specialty Chemicals Division, 3M Company, 3M Center, St. Paul, Minnesota 55144
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  • G. L. Wilkes

    Corresponding author
    1. Department of Chemical Engineering and Polymer Materials & Interfaces Laboratory, Virginia Polytechnic Institute & State University, Blacksburg, Virginia 24061
    • Department of Chemical Engineering and Polymer Materials & Interfaces Laboratory, Virginia Polytechnic Institute & State University, Blacksburg, Virginia 24061
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Abstract

The use of zinc stearate as an ionic plasticizer has been demonstrated to function effectively in a segmented ionene cationomer thereby permitting its melt processability. The ionene polymer is prepared by reacting dimethylamino-terminated polytetramethylene oxide (PTMO) oligomers with various benzyl dihalide compounds, leading to a segmented cationomer. Since the unplasticized ionene polymer undergoes degradation near the softening temperature (ca. 180°C), an ionic plasticizer was incorporated as a means of lowering the softening temperature to prevent degradation and permit melt processability. Zinc stearate was utilized in this study as it has been demonstrated to function well in other ionomers (essentially anionomers) in this capacity. Through the utilization of melt rheological and solid-state morphological investigations, it has been clearly shown that zinc stearate will function effectively as an ionic plasticizer in these quite different ionomer materials by lowering the softening temperature to ca. 120°C, thereby permitting melt processability. In addition, due to the crystallization of the zinc stearate following cooling, this same species also serves to enhance the mechanical properties in the solid state.

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