Study on Processing and Performance Characteristics of Compouns Based on Emulsion / Solution Sbrs

Styrene Butadiene Rubbers (SBRs) are among the most useful synthetic rubbers which can be produced by two different methods of polymerization: emulsion and solution. These two polymerization methods lead to different final properties. In general, SBRs produced by the solution method (S-SBRs) have narrower Molecular Weight Distribution (MWD), higher content of cis-1,4 structure and lower glass transition temperature (Tg), compared to the SBRs produced by the emulsion method (ESBRs). So, compounds based on the solution SBR grades have better dynamic properties; namely higher elasticity, more flexibility and lower heat build-up, which make them suitable to be used in the passenger tire tread compounds. Generally using S-SBRs in tire tread compounds leads to better grip, longer life and lower rolling resistance. In this work two solution grades of SBR, Buna KA8973 and Buna KA8974 (denoted respectively by S-1 and S-2), and an emulsion grade, SBR1712 have been used. SBR1712 contains 23.5% styrene and both solution grades contain 25%; and all three grades are extended with 37.5 phr oil.