Adventures in Dynamically Vulcanized TPEs
Thermoplastic Elastomers
Charles P. Rader
Akron, Ohio
ABSTRACT
Over the past three decades thermoplastic elastomers (TPEs) have had a major impact on the rubber products marketplace. These materials with the processability of a conventional thermoplastic and functional properties of a thermoset rubber have had an unusually high growth rate for the past five decades. Leading this growth has been those TPEs produced by the high-shear/high-temperature mixing of (1) a conventional elastomer, (2) a thermoplastic and (3) a vulcanization system. The resulting product consists of a finely-divided dispersion of crosslinked rubber in a continuous matrix of thermoplastic. Decades of development effort have found these thermoplastic vulcanizates (TPVs) to have useful properties closely approaching those of compounded thermoset rubber. This paper embraces the technical effort required for the successful commercialization of EPDM/polypropylene TPVs, the most widely used class of thermoplastic elastomers (TPEs). This effort required the communication of the science and technology inherent in these materials, as well as the removal of hundreds of barriers to their commercial use. Specific examples will be given of the technical solutions which enabled the meteoric growth of these thermoplastic vulcanizates during the last two decades of the 20th century.