Nonisothermal Vulcanization of Devulcanized GRT with Reversion Type Behavior
Ground rubber tire (GRT) is devulcanized using a coaxial ultrasonic devulcanization reactor at different ultrasonic amplitudes. The devulcanized samples are revulcanized isothermally using a sulfur-based recipe at various temperatures utilizing an advanced polymer analyzer (APA 2000). The curves obtained showed a reversion in the cure that is more pronounced at higher temperatures. A simple vulcanization model is used to fit these cure curves and the corresponding kinetic model parameters are determined. Devulcanized samples are cured nonisothermally in the APA at various constant heating rates and multiple heating steps to verify the ability of this model to predict nonisothermal curing behavior, including reversion. In addition, the cross-link density and gel fraction of the samples cured in the APA are measured and correlated to the state of cure at different times during the curing reaction. Using this information along with the cure kinetics the cross-link density distribution of compression-molded disks are predicted and compared to experimental data.
Journal of Elastomers and Plastics
Isayev, Avraam I. and Sujan, Brijesh, "Nonisothermal Vulcanization of Devulcanized GRT with Reversion Type Behavior" (2006). College of Polymer Science and Polymer Engineering. 38.