ITEC 2014 Paper 41: Butyl Ionomers--A New Class of Butyl Rubber for Tire Inner Liner Applications

Butyl rubber possesses many unique properties including high impermeability to gases and liquids, low temperature flexibility, and broad damping characteristics.  These properties make butyl rubber ideal for numerous consumer end products ranging tire inner liners to adhesives and sealants.  The continued long term growth of butyl rubber for inner liners is driven by the demand for improved air retention and reduced fuel consumption for high performance tires in the modern automobile industry.   A new material based on brominated butyl rubber has been developed which contains a persistant ionic charge attached to the butyl backbone.   The presence of aggregates of the ionic charges within the polymer network act as reversible physical crosslinks resulting in significant changes in the mechanical and rheological properties of the raw polymer.  The resulting compounds show improved green strength, providing improved dimensional stability needed during extrusion and calendering processes.  The final cured article shows significant improved crack growth resistance and adhesion to carcass compounds without impacting the other compound properties.  Such properties may lead to longer lasting tire inner liners, which can be of benefit for retreading operations.  With higher green strength (dimensional stability) and aging resistance (crack growth resistance) the addition of low levels of the butyl ionomer may be of value for OTR tire manufacturing.  Presented by Kevin Kulbaba, Ph.D., Technical Marketing Manager--NAFTA, Butyl Rubber Business Unit, LANXESS Inc.