Abstract: The critical temperature( T c)is a key parameter for prediction of thermodynamic and transport properties by the principle of corresponding states.However,reliable experimental measurements of T c are restricted to stable substances.As a result,numerous estimation methods have become popular for calculation of T c.Among various methods for extimating T c,the group-contribution approach has been widely used.However most methods meed T b of the compounds,and it is difficult to measure T b of unstable substances. In this paper, an estimating method using the d 20 4 for critical properties in group-contribution method was presented and assessed.For correcting the influence of adjacent group and differentiating isomers, the new methods including first-level group-contribution method and second-level group-contribution method are proposed.70 first level groups and 34 second level groups were divided, and the contribution parameters of the groups for T c were obtained by correlating the experimental critical temperature of 325 substances, which are divided into 12 types. The average correlation error of GR1 method and GR2 method for T c is 2.950% and 1.937%,respectively.If the experimental T b is not available, the new method can be used to give satisfactory estimation. The T c of 31 compounds were predicted using the new method and Constantinou-Gani method,respectively, and the results show that the new method demonstrates singnificant improvements in accuracy.

摘要： 提出了不用沸点 (Tb)的估算临界温度 (Tc)的方法———第 1水平基团法和第 2水平基团法 .对烷烃、烯烃、炔烃和二烯烃、环烷烃、芳香烃、醇、酯、醚、酮、酸、含硫化合物、含氮化合物以及卤烃等 12类物质的32 5个Tc 进行了关联 ,得到方程参数及 70个第 1水平基团对Tc 的贡献值以及 34个第 2水平基团对Tc 的贡献值 .新方法不依赖于Tb 的实验值 ,而用更易得到的相对密度d4 2 0 值 ,同时还对分子中相邻基团间的相互作用及同分异构体进行了校正 .新方法用于极不稳定的精细化学品也有良好的精度