ABSTRACT
Quinone diimine antidegradant (Q-Flex QDI) reacts faster than conventional antidegradants to stabilize broken chains and minimize the oxidative chain degradation that occurs during mixing of natural rubber (NR) compounds in intensive mixing equipment. The balance of productivity and performance improves by mixing NR compounds in the presence of Q-Flex QDI antidegradant. QDI has significantly greater probability to react since the Lowest Unoccupied Molecular Orbital surface area is so much larger than that of p-phenylene diamines (PPDs). QDI having a larger reaction surface area, and gaining energy of stabilization through the aromatization process, provides for higher reaction rate with radicals compared to the PPD molecules. The unit power to mix can be generally described as a function of the rotor surface area, the revolutions per minute used during mixing, the time required to reach dump temperature for the first pass mix, and a treatment for the type of antidegradant used.
