EXXPRO(TM) elastomers are used in the manufacturing of tires as well as in a broad range of other automobile and industrial applications. This elastomer (denoted as BIMS) is a random copolymer of p-methylstrene (MS) and polyisobutylene (I) with varying degrees of PMS content and bromination (B) on the p-methyl group. BIMS is highly impermeable to gases, and exhibits outstanding heat, ozone and flex resistance. In a number of applications, general purpose elastomers are blended with BIMS materials. In order for these materials to adhere it is important to understand their interfacial properties. The interfacial width between polybutadiene and BIMS is a sensitive function of both the bromination level and PMS content. Using neutron reflectivity (NR), we studied the dynamics of interface formation as a function of time and temperature for BIMS with varying degrees of PMS and bromine. We found that in addition to the bulk parameters, the total film thickness and the proximity of an interactive surface can affect the interfacial interaction rates. Furthermore, the interfacial properties can be modified by the inclusion of particles, such as carbon black (a filler component in tire rubbers). Results will be presented on the relation between the interfacial width as measured by NR and compatibilization studies via atomic force microscopy and lateral force microscopy.
