Acta Phys. -Chim. Sin. ›› 2002, Vol. 18 ›› Issue (02): 166-169.doi: 10.3866/PKU.WHXB20020215

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Low Temperature Heat Capacities and Thermal Analysis of N-(p-methylphenyl)-N′-(2-pyridyl)urea

Lu Qin-Ying;Song Yong-Ji;Meng Shuang-He;Xing Jun;Tan Zhi-Cheng   

  1. Thermochemistry Laboratory, Dalian Institute of Chemical Physics,Chinese Academy of Sciences, Dalian 116023;Department of Chemical Engineering,Beijing Institute of Petrochemical Technology, Beijing 102600;Dalian Technology Center,the Lubrication Company of China National Petroleum Corporation, Dalian 116031
  • Received:2001-08-15 Revised:2001-10-08 Published:2002-02-15
  • Contact: Song Yong-Ji

Abstract: Heat capacities of N-(p-methylphenyl)-N′-(2-pyridyl)urea were determined by low temperature adiabatic calorimetry in the temperature range of 80 to 370 K. It is found that there is no heat anomaly in this temperature region. With the experimental heat capacities thermodynamic functions were calculated. To investigate the thermal stability and decomposition characteristics of N-(p-methylphenyl)-N′-(2-pyridyl)urea, DSC and TG experiments were carried out. The results indicated that N-(p-methylphenyl)-N′-(2-pyridyl)urea started to melt at 153 ℃ and the melting peak located at 173.86 ℃. The melting enthalpy is 204.45 kJ•mol-1. The decomposition peak of N-(p-methylphenyl)-N′-(2-pyridyl)urea was found at 226.11 ℃ from DSC curve. This result is similar with that from TG and DTG experiment, in which the weight loss peak was determined as 227.2 ℃.

Key words: N-(p-methylphenyl)-N′-(2-pyridyl)urea, Adiabatic calorimetry, Thermodynamic function, Thermal analysis