Estimativa por DSC das entalpias de sublimação da etilenouréia e da propilenouréia: algumas correlações empíricas envolvendo amidas e tioamidas Estimative by DSC data of the sublimation enthalpies for ethyleneurea and propyleneurea: some empirical correlations with amides and tioamides

• Main Author: Robson Fernandes de Farias
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 1999-07-01
• Series: Química Nova
• Subjects: amides; sublimation enthalpy; vaporization enthalpy
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40421999000400008

<abstract language="eng">By using DSC data, the enthaplies of sublimation for ethyleneurea and propyleneurea, are calculated as 84 and 89 kJ mol-1 respectively. Using the vaporization enthalpy values for dimethylethyleneurea and dimethylprophyleneurea, as obtained from literature, the empirical relation: <FONT FACE="Symbol">D</font>crg Hmo (1)/ <FONT FACE="Symbol">D</font>crg Hmo (2) = <FONT FACE="Symbol">D</font>lg Hmo (1)/ <FONT FACE="Symbol">D</font>lg Hmo(2) = constant, that relate sublimation or vaporization enthalpies of two different substances and of its methylated derivatives, is obtained. Correlations like that are found to another ureas and thioureas.