Effect of Carbon-Black Filler and Processing Oil on Ultrasound Devulcanization of Isoprene Rubber

ORAL

Abstract

In support of a novel approach to rubber recycling, we continue our investigation of the effects of intense ultrasound on isoprene rubber by studying molecular and segmental mobilities of the host rubber vulcanized in the presence of 35 phr carbon-black filler with and without 10 phr plasticizing processing oil. We measured wide-line transverse NMR relaxation (T$_{2})$. The magnetization decays followed a bimodal distribution, distinguishing physical and chemical network (short T$_{2})$ from lighter sol, dangling chain ends, and trace oligomers (long T$_{2})$. Pulsed-gradient diffusion measurements failed because the high melt molecular weight contained insufficient longer-T$_{2}$ sol components. It was found that, corrected for oil where present, chemically extractable sol fractions were reduced to about 2/3 of those in unfilled vulcanizates at equal ultrasound exposure. Black filler modestly decreased all segmental mobilities, whereas processing oil slightly increased them. This relative insensitivity to additives supports earlier conclusions that the efficiency of the ultrasound method is uncompromised by the solid filler and extender oils used in rubber-based industrial products.

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Authors

  • Ernst von Meerwall

  • William H. Rauckhorst

    Gothenburg University, Denison University, Bowling Green State University, NASA Glenn Research Center, Ohio Wesleyan University, Nitronex Corporation, 2305 Presidential Drive, Durham, NC, AFRL/MLPS, Wright-Patterson AFB, OH, Miami University, Ursinus College, Purdue University Calumet, GSI, Florida State University, Carnegie Mellon University, Dept. of Health Sciences, Cleveland State University, Physics Dept., Cleveland State University, University of Rochester, OMI College of Applied Science, University of Cincinnati, Davis and Elkins College, WV, Schlumberger-Doll, Korea Institute of Science and Technology, University of Cincinnati, Lock Haven University of Pennsylvania, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372, Albion College, Albion, MI 49224, University of Toledo, Toledo, OH 43606, Youngstown State University, Joint Institute for Nuclear Research (Dubna), Naval Research Laboratory, ManTech SRS Technologies, Inc., Ecopulse, Inc., Army Research Laboratory, University of Surrey, The Ohio State University, Univ. Akron, Owens Community College, Toledo, OH

  • William H. Rauckhorst

    Gothenburg University, Denison University, Bowling Green State University, NASA Glenn Research Center, Ohio Wesleyan University, Nitronex Corporation, 2305 Presidential Drive, Durham, NC, AFRL/MLPS, Wright-Patterson AFB, OH, Miami University, Ursinus College, Purdue University Calumet, GSI, Florida State University, Carnegie Mellon University, Dept. of Health Sciences, Cleveland State University, Physics Dept., Cleveland State University, University of Rochester, OMI College of Applied Science, University of Cincinnati, Davis and Elkins College, WV, Schlumberger-Doll, Korea Institute of Science and Technology, University of Cincinnati, Lock Haven University of Pennsylvania, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372, Albion College, Albion, MI 49224, University of Toledo, Toledo, OH 43606, Youngstown State University, Joint Institute for Nuclear Research (Dubna), Naval Research Laboratory, ManTech SRS Technologies, Inc., Ecopulse, Inc., Army Research Laboratory, University of Surrey, The Ohio State University, Univ. Akron, Owens Community College, Toledo, OH

  • William H. Rauckhorst

    Gothenburg University, Denison University, Bowling Green State University, NASA Glenn Research Center, Ohio Wesleyan University, Nitronex Corporation, 2305 Presidential Drive, Durham, NC, AFRL/MLPS, Wright-Patterson AFB, OH, Miami University, Ursinus College, Purdue University Calumet, GSI, Florida State University, Carnegie Mellon University, Dept. of Health Sciences, Cleveland State University, Physics Dept., Cleveland State University, University of Rochester, OMI College of Applied Science, University of Cincinnati, Davis and Elkins College, WV, Schlumberger-Doll, Korea Institute of Science and Technology, University of Cincinnati, Lock Haven University of Pennsylvania, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372, Albion College, Albion, MI 49224, University of Toledo, Toledo, OH 43606, Youngstown State University, Joint Institute for Nuclear Research (Dubna), Naval Research Laboratory, ManTech SRS Technologies, Inc., Ecopulse, Inc., Army Research Laboratory, University of Surrey, The Ohio State University, Univ. Akron, Owens Community College, Toledo, OH