| NUKLEONIKA 2009, 54(2):71-75
RADIATION CURING OF SILICA FOR SILICA-RUBBER COMPOSITESDaniele Dondi1, Claudia Palamini1, Fabio Pepori1, Armando Buttafava1, Pietro Galinetto2, Antonio Faucitano1 1 General Chemistry Department, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy 2 Department of General Physics, University of Pavia, Via Bassi 6, 27100 Pavia, Italy The functional modification of silica samples based on the reaction of “grafting” of polybutadiene olygomers carried out by gama-irradiation in the presence of air at room temperature has been investigated. The yield of grafted PB reaches a maximum at doses of about 30 kGy, then decreases as a consequence of the oxidative degradation. The reaction is accompanied by the build up of carbonyls and peroxides up to 0.1 moles/kg and it leads to a rapid consumption of the double bonds concentration as determined by both FTIR and Raman spectroscopy. The results of the EPR analysis are diagnostic of a mechanism of immobilization of the olygomer based on cross-linking of polybutadiene which is initiated by the SiO2 radiolytic species. Depending on the nature of the SiO2 species, the mechanism of initiation leads to immobilized PB either really grafted to the silica surface or simply physically absorbed. Close X |