Process for devulcanizing rubber
A process for devulcanizing EPDM rubber comprising the step of introducing sulfur-cured EPDM to an extruder, introducing from about 0.5 to about 20 wt % scavenging agent, based upon the total weight of the EPDM and scavenging agent, and mixing and masticating the EPDM at a temperature sufficient to at least partially devulcanize the sulfur-cured EPDM.
1. A process for devulcanizing EPDM rubber comprising the steps of:
introducing sulfur-cured EPDM to an extruder;
introducing an oxide or a carbonate of an alkali metal or alkaline earth metal to the extruder, wherein the oxide or a carbonate of an alkali metal or alkaline earth metal is introduced so as to protect against degradation of the extruder; and
mixing and masticating the EPDM within the extruder in the presence of the oxide or a carbonate of an alkali metal or alkaline earth metal at a temperature sufficient to at least partially devulcanize the sulfur-cured EPDM.
2. The process of claim 1 , further comprising the step of removing volatiles from the extruder.
3. The process of claim 2 , where the volatiles are removed from a vent.
4. The process of claim 1 , where said step of introducing includes introducing from about 0.5 to about 20 wt % of the oxide or a carbonate of an alkali metal or alkaline earth metal based upon the total weight of the EPDM and the oxide or a carbonate of an alkali metal or alkaline earth metal.
5. The process of claim 1 , where said step of introducing includes introducing from about 1.0 to about 10 wt % of the oxide or a carbonate of an alkali metal or alkaline earth metal based upon the total weight of the EPDM and the oxide or a carbonate of an alkali metal or alkaline earth metal.
6. The process of claim 1 , where said step of introducing includes introducing from about 1.5 to about 5 wt % of the oxide or a carbonate of an alkali metal or alkaline earth metal based upon the total weight of the EPDM and the oxide or a carbonate of an alkali metal or alkaline earth metal.