Journal of Applied Polymer Science, Vol.115, No.2, 692-701, 2010
Effect of the Temperature on the Kinetic of Natural Rubber Vulcanization with the Sulfur Donor Agent Dipentamethylene Thiuram Tetrasulphide
The effect of the temperature on the kinetics of vulcanization of natural rubber with the sulfur donor agent dipentamethylene thiuram tetrasulphide (DPTT) was investigated. The oscillatory disk rheometer and differential scanning calorimetry under dynamic and isothermal conditions were used. The Coran's model was applied to set the kinetic constants within each distinct step of the vulcanization process using the obtained values of the rheometer curves. During the curing period it was observed that there were two stages. Either the torque increment (AS) or the crosslink density arise a maximum value at 130 C. The dynamic and isothermal thermograms showed two overlapped peaks during the curing reaction. These results were in concordance with those obtained by curemeter testing. In addition, the activation energy of the vulcanization process was also calculated by means of both techniques. (C) 2009 Wiley Periodicals, Inc. J Appl Polyrn Sci 115: 692-701, 2010
Keywords:kinetic;torque rheometer;differential scanning calorimetry;sulfur free vulcanization;elastomers