Abstract: In this work, the equation of state for Methyl tert-butyl ether (MTBE) has been developed based on the published experimental data using the Helmholtz energy as the fundamental property with independent variables of density and temperature. Overall, the uncertainty of the equation of state is 1.0% in vapor pressure bellow 430 K, and increases as the temperature increases due to a lack of experimental data. The uncertainty in density ranges from 0.1% in the liquid region to 1.0% elsewhere, including the critical and vapor regions. The uncertainties in the properties related to energy (such as heat capacity and sound speed) are estimated to be 0.5%. In the critical region, the uncertainties are higher for all properties except vapor pressure. The behavior of the equation of state is reasonable within the region of validity and at higher and lower temperatures and pressures. A detailed analysis has been performed in the article.

摘要： 利用公开发表的实验数据开发了甲基叔丁基醚（MTBE）的状态方程，方程以Helmholtz自由能为显式、以温度和密度为自变量。方程计算饱和蒸气压的不确定度430 K以下为1.0%，随着温度的升高，由于缺少实验数据不确定度增大为2.0%。方程计算密度的不确定度由液相区的0.2% 变到临界区和气相区的1.0%。方程计算能量相关物性（如比热容和音速）的不确定度为0.5%。临界区，除了饱和蒸气压，方程计算所有其它热力学性质的不确定度都较高。正如文中分析，本文方程不但能准确的复现实验数据，而且方程的外推性也是合理的。文中对方程进行了详细的分析。

关键词: 甲基叔丁基醚, 状态方程, 热力学性质