Orientational Effects and Random Mixing in 1-Alkanol + Alkanone Mixtures

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• 作者：Juan Antonio Gonz谩lez ; 脕ngela Mediavilla ; Isa铆as Garc铆a de la Fuente ; Jos茅 Carlos Cobos ; Cristina Alonso Trist谩n ; Nicol谩s Riesco
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：July 31, 2013
• 年：2013
• 卷：52
• 期：30
• 页码：10317-10328
• 全文大小：504K
• 年卷期：v.52,no.30(July 31, 2013)
• ISSN：1520-5045

文摘

1-Alkanol + alkanone systems have been investigated through the data analysis of molar excess functions, enthalpies, isobaric heat capacities, volumes and entropies, and using the Flory model and the formalism of the concentration-concentration structure factor (S_CC(0)). The enthalpy of the hydroxyl-carbonyl interactions has been evaluated. These interactions are stronger in mixtures with shorter alcohols (methanol-1-butanol) and 2-propanone or 2-butanone. However, effects related to the self-association of alcohols and to solvation between unlike molecules are of minor importance when compared with those which arise from dipolar interactions. Physical interactions are more relevant in mixtures with longer 1-alkanols. The studied systems are characterized by large structural effects. The variation of the molar excess enthalpy with the alcohol size along systems with a given ketone or with the alkanone size in solutions with a given alcohol are discussed in terms of the different contributions to this excess function. Mixtures with methanol show rather large orientational effects. The random mixing hypothesis is attained to a large extent for mixtures with 1-alkanols 鈮?methanol and 2-alkanones. Steric effects and cyclization lead to stronger orientational effects in mixtures with 3-pentanone, 4-heptanone, or cyclohexanone. The increase of temperature weakens orientational effects. Results from S_CC(0) calculations show that homocoordination is predominant and support conclusions obtained from the Flory model.