Heat Capacities and Thermodynamic Properties of 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic Acid  

作　　者：XUE Bin WANG Jian-ya TAN Zhi-cheng WU Tong-hao 

机构地区：[1]School of Petrochemical Engineering, Shenyang University of Technology, Liaoyang 111003, P. R. China [2]College of Chemistry, Jilin University, Changchun 130021, P. R. China [3]Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, P. R. China

出　　处：《Chemical Research in Chinese Universities》2007年第4期460-464,共5页高等学校化学研究（英文版）

基　　金：Supported by the Education Bureau Science Foundation of Liaoning Province,China(No.20040261).

摘　　要：The heat capacities of 3-（ 2,2-dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic acid （a racemic mixture, molar ratio of cis-/trans-structure is 35/65） in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% （ molar fraction）. A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and en- tropy of fusion, △fusHm, △fusSm, of the acid were determined to be （331.48±0.03 ） K, （16.321±0.031） kJ/mol, and （49.24±0.19） J/（ K·mol）, respectively. The thermodynamic functions of the sample, Ht-H298.15, Sr-S298.15 and Gr-G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric（TG） analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7.3 ×10^7 min^-1 , E =70.64 kJ/mol, respectively.The heat capacities of 3-（ 2,2-dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic acid （a racemic mixture, molar ratio of cis-/trans-structure is 35/65） in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% （ molar fraction）. A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and en- tropy of fusion, △fusHm, △fusSm, of the acid were determined to be （331.48±0.03 ） K, （16.321±0.031） kJ/mol, and （49.24±0.19） J/（ K·mol）, respectively. The thermodynamic functions of the sample, Ht-H298.15, Sr-S298.15 and Gr-G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric（TG） analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7.3 ×10^7 min^-1 , E =70.64 kJ/mol, respectively.

关 键 词：3-（2 2-Dichloroethenyl）-2 2-dimethylcyclopropanecarboxylic acid Adiabatic calorimetry Heat capacity Thermodynamic function Thermal decomposition 

分 类 号：TQ453[化学工程—农药化工]