Synthesis and Application of Polybutadiene-g-Polypentafluorostyrene in Rubber

Perfluorinated aromatic rings (electron-deficient) interact with aromatic hydrocarbons (electron-rich) by pi-pi stacking interactions. Since many rubber fillers, such as carbon black and lignin, are based on electron-rich aromatic systems, coupling agents containing aromatic fluorocarbons may improve the interaction between these non-polar and polar fillers and the non-polar rubber matrix. Graft copolymers of polybutadiene grafted with poly(pentafluorostyrene) combine the non-polar polybutadiene backbone, typical of rubber matrices, with grafts containing multiple perfloroarene groups that are capable of interacting with typical fillers. This talk will present the synthesis of polybutadiene-graft-polypentafluorostyrene (PB-g-PPFS), including the effects of temperature, initiator concentration, and reaction time on the graft efficiency, graft frequency and graft ratio from benzyoyl peroxide-initiated polymerizations of pentafluorostyrene in the presence of polybutadiene. Arene-perfluoroarene interactions between electron-rich lignin and electron-deficient pentafluorostyrene (PFS) in PB-g-PPFS lead to improved strength and a reduction in the rolling resistance indicators. Applying the same concept to carbon black-filled rubber, the cure rate improved and the rolling resistance decreased by 13%.