用精密自动绝热量热计测定了苯氧乙酸嘧霉胺盐在81~380K之间的低温热容.结果表明,该化合物在81-328K之间无相变和热异常现象发生,在328~354K之间发生固-液熔化,其熔化温度、摩尔熔化焓和摩尔熔化熵分别为(349.380.03)K,(34279±10)kJ/mol和(98.13±0.05)J/(K·mol).根据热力学函数关系式计算出苯氧乙酸嘧霉胺盐在80~325K之间以标准状态(298.15K)为基准的热力学函数值.
Low-temperature heat capacities of Pyrimethanil phenoxyacetate ( C20H21N3O3 ) were precisely measured with a high-precision automated adiabatic calorimeter over the temperature range between 81 to 380 K. The compound was observed to melt at(349.38 ±0.04) K. The molar enthalpy △fusHm, and entropy of fusion, △fusSm of the compound were determined to be (34 279 ± 10) J/mol, (98.13 ± 0.05 ) J/( mol · K), respectively. The thermodynamic function data relative to the reference temperature(298.15 K) were calculated based on the heat capacities measurements in the temperature range from 80 K to 325 K.