Analysis on Partition Behavior of Hydrocarbon Resins in Tire Compounds of an Immiscible Blend

摘要

There has appeared intensive interests in using various resins for improvement of tire tread compound performance characteristics.A proper understanding of how resin molecules distribute in and interact with matrix polymers is of obvious importance for such purpose.Here cured carbon black-filled compounds made of an immiscible blend of high-cis polybutadiene rubber(BR)and natural rubber(NR)are employed as model systems for revelation of resin interactions with different polymers.The relationship between the shift in compound glass transition temperature as measured via dynamic mechanical testing and the resin concentration in the compound is first established for compounds of a single polymer(BR or NR).Such a relationship is then assumed to also hold for the same polymer phase in compounds of an immiscible blend.In this way,the resin partition behavior in a blend of BR and NR can be systematically analyzed.Such analysis is applied to four different resins of similar softening point at about 100 °C.The estimates indicate that with increasing resin polarity,partition of resin changes from primarily residing in the NR phase to mainly residing in the BR phase.Hence a full spectrum of partition behavior has been detected with these four different resins.