甲苯二异氰酸酯相关合成体系密度的测定与关联

Measurement and correlation of density for related toluene diisocynate synthesis system

甲苯二异氰酸酯是重要的有机中间体,为了提供其相关合成反应的工业化设计所必需的密度、超额体积等关键物性数据,选定基础原料甲醇、乙醇、氨基甲酸甲酯为研究对象.分别用激光法测定了常压下甲醇+氨基甲酸甲酯和乙醇+氨基甲酸甲酯体系在293.15、308.15K下固体溶质在液体中的溶解度,用间接测量法得到了相应条件下体系的混合密度,然后通过密度进一步计算得到了超额体积.对于上述体系,不同条件下各混合液的过量体积均为负;溶液组成一定时,超额体积随着温度的增加而减小;体系温度一定时,超额体积随着氨基甲酸甲酯摩尔分数的增加而减小.同时,对于不同温度下甲醇+氨基甲酸甲酯、乙醇+氨基甲酸甲酯体系密度与组成的关系,超额体积与组成的关系进行了线性关联,回归所得模型系数的最大标准偏差小于0.5%;用Redlich-Kister方程拟合了不同温度下的超额体积与组成的关系,回归所得模型参数的最大标准偏差小于5%.结果表明模型方程可适用于回归上述体系的物性数据.

Toluene diisocynate is an important organic intermediate. Methanol, ethanol and urethylane are key raw materials of toluene diisocynate synthesis. They are chosen to be the research object in order to provide the industry design of necessary physical data density and excess volume. Solubilities of the binary mixtures of methanol-urethylane and ethanol-urethylane at different compositions were determined at the temperature range from 293.15 K to 308. 15 K and under atmospheric pressure by laser method, and mixture densities were measured by indirect method, then excess molar volumes were calculated by the density data. For the systems, excess molar volumes were negative; in addition, it decreased with the temperature rise as composition unchanged, and it decreased with the temperature rise as composition unchanged. Densities and compositions were correlated with linear model, and the standard deviations of the regression coefficients were lower than 0. 5% ; excess molar volumes and compositions were correlated with the Redlieh-Kister equation, and the standard deviations of the regression coefficients were lower than 5 %. Results show that the linear model and Redlich-Kister can be used to correlate the two mentioned physical properties of the two systems.