Preparation and characterization of cyclo olefin copolymer (COC)/silica nanoparticle composites by solution blending

A series of organic cyclo olefin copolymer (COC)/SiO₂ nanocomposites, containing 1, 5, 10 and 15 wt% SiO₂ nanoparticles, were prepared by solution blending. The differential scanning calorimetric (DSC) analysis indicated that the glass transition temperature (T _g) of composites were higher than that of pure COC and raised significantly as the SiO₂ content increased from 1 to 15 wt%. The decomposition temperatures (Td) of composites were investigated by thermogravimetric analyzer (TGA) and showed 13 °C increase by the addition of 15 wt% SiO₂ when compared to pure COC. From the scanning electron microscopic (SEM) observation, finer size of silica was dispersed in the COC matrix without large agglomerates. The light transmittance of COC/SiO₂ composites was still higher than 85% as the SiO₂ content up to 10 wt%. The oxygen barrier property of the composite film show significant improvement when compared to pure COC.