Deciphering the silica/silane reaction mechanism for the development of a new generation of low rolling resistance: Part 2 – Transfer of results from model examinations into practice

By use of suitable organic silanes and controlled mixing conditions, silica/silane systems have proven to be well suited for tire tread formulations with reduced rolling resistance. The bifunctional organosilane is able to react with the silica surface as well as with the polymer. However, silica compounds still present considerable difficulties in processing. The kneader is not only a mixing aggregate but has to fulfill the role of a chemical reactor. It is known from former studies, that the reaction between the silica and the silane is complex. It is up to now not sufficiently understood. Therefore, a better understanding would help many tire producers to control the mixing process more efficiently. Part 1 has shown how Operando IR spectroscopy can be employed to decipher the reaction mechanism. In part 2 the method is used to investigate the reaction of several silica samples with different silanol group densities. Molecular modelling has been used in order to understand the sterical aspects of the reaction. The gained knowledge was used to develop two new silica/silane systems for passenger car tire treads. Their properties in tire treads have been investigated