Assessment of the thermodynamic properties of poly(2,2,2-trifluoroethyl methacrylate) by inverse gas chromatography

• Published in: Journal of Chromatography A 2014-01, Vol.1324, p.207-214
• Main Authors: Papadopoulou, Stella K., Panayiotou, Costas
• Format: Article
• Language: English
• Subjects: Applied sciences; Assessments; Dilution; Exact sciences and technology; Fluorinated polymethacrylates; Interaction parameters; Inverse gas chromatography; Organic polymers; Physicochemistry of polymers; Properties and characterization; Solubility parameter; Solubility parameters; Solution and gel properties; Solvents; Thermal and thermodynamic properties; Thermodynamic properties; Thermodynamics
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2013.11.044

•Temperature and functional group dependence of thermodynamic parameters.•Why δp and δhb increase with increasing temperature?•PTFEMA soluble in chloroform, 1,4-dioxane and ketones at high temperatures.•PTFEMA more soluble than poly(fluoroalkyl methacrylates) of higher fluorine content. The thermodynamic properties of poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) were determined by the aid of the inverse gas chromatography technique (IGC), at infinite dilution. The interactions between the polymer and 15 solvents were examined in the temperature range of 120–150°C via the estimation of the thermodynamic sorption parameters, the parameters of mixing at infinite dilution, the weight fraction activity coefficients and the Flory–Huggins interaction parameters. Additionally, the total and the partial solubility parameters of PTFEMA were estimated. The findings of this work indicate that the type and strength of the intermolecular interactions between the polymer and the solvents are strongly depended on the functional groups of the polymer and the solvents. The proton acceptor character of the polymer is responsible for the preferential solubility of PTFEMA in chloroform which acts as a proton donor solvent. The results also reveal that the polymer is insoluble in alkanes and alcohols whereas it presents good miscibility with polar solvents, especially with 2-butanone, 2-pentanone and 1,4-dioxane. Furthermore, the total and dispersive solubility parameters appear diminishing upon temperature rise, whereas the opposite behavior is noticed for the polar and hydrogen bonding solubility parameters. The latter increase with temperature, probably, due to conformational changes of the polymer on the solid support. Finally, comparison of the solubilization profiles of fluorinated methacrylic polymers studied by IGC, leads to the conclusion that PTFEMA is more soluble compared to polymers with higher fluorine content.