MECHANICAL PROPERTY OF SURFACE MODIFIED SILICA NANOPARTICLE FILLED POLY (ETHYLENE 2,6-NAPHTHALATE)

摘要

The effect of stearic acid on the mechanical property of silica nanoparticle reinforced poly (ethylene 2, 6-naphthalate) (PEN) composites were investigated. Melt viscosity of the composites were decreased by employing silica nanoparticle into the PEN. Tensile modulus of the composites reinforced with unmodified silica nanoparticle was increased with the silica contents, while tensile strength and elongation of those were decreased. However, the stearic acid modified silica nanoparticle reinforced PEN composites exhibited increased elongation and decreased tensile modulus with the contents, because stearic acid which adsorbed on the surface of silica nanoparticle more than monolayer could act as plasticizer. Stearic acid modification of the silica nanoparticle did not have an effect on the crystallization behaviors of the composites. Theoretical tensile modulus values were calculated using Einstein, Kerner, and Nielsen's equations, and compared to experimental values of the composites, and dispersion state of the nanoparticle were observed by FE-SEM.