碳酸二甲酯相关体系黏度和密度的测定及关联

Measurement and Correlation of Densities and Viscosities for Correlative Systems of Dimethyl Carbonate

在常压下采用U形振动管密度计测定了碳酸二甲酯与正己烷在293.15~333.15K下的密度以及碳酸二甲酯分别与正庚烷和异辛烷所组成的二元混合液在293.15~343.15K下的密度;用乌氏黏度计测定了这3个二元混合溶液在相应温度下的黏度.密度测量误差低于±1×10-5g/cm3,黏度测量误差低于±0.003mPa/s,并由密度数据计算出超额摩尔体积VE,由黏度数据计算出了不同温度和组成下的混合黏度的变化Δη.计算所得VE全部为正值,Δη全部为负值.对不同温度下的超额摩尔体积、混合黏度的变化与组成的关系按多项式方程进行了关联,并给出了多元回归系数和标准偏差.

Densities and dynamic viscosities for the binary system of dimethyl carbonate and hexane at the (temperatures) (293.15~333.15 K) and the binary systems of dimethyl carbonate and heptane and dimethyl (carbonate) and isooctane at the temperatures (293.15~343.15 K) were measured over the whole mole fraction range at atmospheric pressure by using a vibrating U-shaped sample tube densimeter and Ubbelohde (suspendedlevel) viscometer. The measurement errors were less than ±1×10^(-5) g·cm^(-3) for density and (±0.003) mPa·s for viscosity. Densities were used in calculation of excess molar volumes. Viscosities were used in calculation of deviations in viscosity. All the excess molar volumes were positive for the three systems. The dynamic (viscosity) deviations for the three systems were all negative in all the composition range. The (correlations) between (composition) and excess molar volume and composition and deviation in viscosity data were carried out respectively with polynomial equation to evaluate their feasibility for these systems. The polynomial fitting coefficients and standard deviations were given.