Effect of Organo-Functionalized Silica Particles on the Mechanical Properties of PU

Monodisperse, spherical, organo-functionalized silica particles were prepared by a one-pot method. Vinyl-silica and amine-silica were prepared by the hydrolysis of tetraethyl orthosilicate in aqueous alcohol solutions with the addition of vinyl triethoxysilane and 3-aminepropyl triethoxysilane, respectively, while thiol-silica was prepared by the hydrolysis of 3-mercaptopropyl in water without ethanol. The organo-functionalized silica particles were characterized by transmission electron microscopy, scanning electron microscopy and energy dispersive spectrometer. Organo-silica particles had lower water swell by introduction of organic groups on the surface of silica particles. Afterwards, organo-functionalized silica particles were dispersed in polyurethane (PU) to improve the mechanical properties of PU. The mechanical properties of PU films were measured by universal testing machine and sclerometer. The results showed that the tensile strength, Flexural strength and hardness of PU films were obviously improved with the addition of organo-silica particles.