文摘
Carbodiimide based UV curable coating materials, which were developed as a high refractive raw coating material, were prepared by dispersion with fumed silica inorganic particles in order to overcome low hardness and strength of the cured films. Three kinds of fumed silica particles were dispersed having various reactive surfaces, and the rheological behavior of the dispersions was observed. Compared to the hydrophilic silica (Si-hi) dispersion, two types of hydrophobic silica (Si-ho-n and Si-ho-a) dispersion showed sol behavior in high concentrations. In particular, the Si-ho-a dispersion showed viscous sol characteristics for high shear rates. The surface hardness of the film obtained by UV curing of the fumed silica dispersion increased in the more highly concentrated dispersion, and the haze of the film also increased. Further, the film was highly refractive. The slurry polymerization reactors on the industrial scale operate in continuous mode at low monomer conversion per pass to minimize mass and heat transfer limitations. Nevertheless, for the screening of catalytic systems, the laboratory tests are carried out using batch or semi-batch reactors. In this work, ethylene/propylene copolymers were synthesized in a semi-continuous reactor under similar conditions, where the only difference involves the modification of the feed ratio during the reaction. The key point of the control system is a micro-gas chromatograph (MGC), which analyzes the molar ratio ethylene (C 2) to propylene (C 3) in the gas phase during the reaction, and the composition in the liquid phase was calculated using the Soave-Redlich-Kwong equation of state. The effect of the ethylene/propylene copolymer microstructure has been studied using different techniques that allow us to conclude that the method of synthesis influences the comonomer distribution and the final copolymer properties.