Synthesis Of Pb/silica Hybid Nanoparticles And Preliminary Study Of The Influence On Rubber Reinforcement

PB/SiO₂hybrid nanoparticles were synthesized by two methods:hydrolization of chlorosilane-functionalized PB and using anionicpolymerization techniques together with the “grafting to” approach.1. PB/silica hybrid materials were synthesized by hydrolization ofchlorosilane-functionalized PB prepared by anionic polymerization.Structure of the PB/silica hybrid material was characterized by GPC, TGand FT-IR, microstructure of the product was characterized by TEM,HRTEM and laser diffraction particle size analyzer. The factors that affectproduct such as molecular weight of PB, reaction time, concentration andamounts of SiCl4, amounts and introducing way of H₂O and ways ofremoving solvent were discussed. The results indicated that the PB/SiO₂hybrid material was spherical nanoparticles. The PB/silica hybrid contentin product increased with extending reaction time, decreasing molecularweight of PB, the PB/SiO₂hybrid nanoparticles content in product washigher, when solvents were removed gradually by evaporating and adding H₂O to chlorosilane-functionalized PB. PB/SiO₂hybrid nanoparticlescontent in product was the maximum when n（H₂O）/n（Cl） was2.2. Polymer/silica hybrid materials were prepared using “grafting to”technique for functionalizing commercial silica particles with anionicpolymers of PS and PB. The factors that affect dispersion of silica such asdrying, dispersion medium, solubilizer, time and way of dispersion werediscussed. The results indicated that water content of precipitated silicawas about7.0%, water content of fumed silica was about1.6%, silicaparticles agglomerated more serious after being dried, silica particlesagglomerations were dendritic and difficult to be destroyed, adding（CH3）3SiCl, phenyl isocyanate and BuLi as solubilizer can improveddispersion of silica of which （CH3）3SiCl had the best effect, high-speedmechanical agitation and extending time of external mechanical forcescan improved dispersion of silica, when SBR was reinforced by thePB/silica hybrid material, curing time was increased. Although the basicmechanical properties of the SBR vulcanizate were improved, thereinforcing effect was not very ideal, the value of elongation at break ofthe SBR vulcanizate was high and the value of tensile stress at100%and300%was low.