Comparison of using DHBP and TMCH peroxides on the mechanicalproperties of PP/POE thermoplastic vulcanizates prepared by reactiveextrusion

Thermoplastic vulcanizates (TPV) are prepared using dynamic vulcanization of the elastomeric phaseduring melt mixing. One of the most common types of these mixtures is the combination ofpolypropylene (PP) and polyolefin elastomer (POE). While curing the elastomeric phase in the meltmixing process, peroxides cause the breakdown of the PP chain and the loss of physical-mechanicalproperties of the final mixture. In addition, it is necessary to complete the curing process of theelastomeric phase during the residence time in the extruder. Therefore, it is important to achieve anoptimal time for POE vulcanization and prevent PP degradation by using a peroxide with a suitablehalf-life time. In this research, the effect of two different peroxides with different structures and halflifetime has been investigated in order to complete the curing of the elastomeric phase as much aspossible in the reactive extrusion stage. It was found that using ۱,۱-Di(tert.butylperoxy)-۳,۳,۵-trimethylcyclohexane (TMCH) instead of ۲,۵-Dimethyl-۲,۵-di(tert.butylperoxy)hexane (DHBP)improved the mechanical properties of TPV while maintaining the hardness, due to the shorter halflifetime and the completion of the curing reaction during the residence time in the extruder. TMCHcaused the fracture energy density of the samples to increase more than twice in the tensile test incomparison with DHBP.

کلیدواژه ها:

Sustainable Solution ، Thermoplastic Vulcanizate ، Reactive Extrusion ، PolyolefinElastomer ، Dynamic Vulcanization