1-Propanol-water mixture, properties

Sato, T., Chiba, A., and Nozaki, R. (2000). Composition-dependent dynamical structures of 1-propanol-water mixtures determined by dynamical dielectric properties J. Chem. Phys., 113, 9748-9758. 

Table 8.10 displays some important thermodynamic properties of the reactive mixture. The components form azeotropes each other. The ester is the highest boiler, followed by the acid, and at large distance by water and 1-propanol. The RD column operates by diluting the product with some alcohol, which can be recycled after product conditioning. Without further treatment, the top distillate would be the azeotrope n-propanol/water. 

A test set of 6 to 13 aroma compound partition coefficients between different food contact polymers (low density polyethylene (LDPE), high density polyethylene (HDPE) polypropylene (PP), polyethylene terephthalate (PET), polyamide (PA)) and different food simulant phases (water, ethanol, aqueous ethanol/water mixtures, methanol, 1-propanol) were taken from the literature (Koszinowski and Piringer, 1989, Baner, 1992, Franz, 1990, Koszinowski, 1986, Franz, 1991, Baner, 1993, Piringer, 1992). Table 4-2 shows the test set of 13 different aroma compounds, with their properties and their structures. The experimental data were compared to estimations using different estimation methods of UNIFAC-FV, GCFLORY (1990), GCFLORY (1994) and ELBRO-FV. 

The effect cf the addition of F to the starting mixture on the adsorption and the catalytic properties is quite significant. For example, the hydrophobicity of purely ailioecua sasplea ia conaide-rably enhanced (lesa Si-OH groupa). Figure 6 ahows that such a material adsorbs acre n-propanol frea a dilute n-propanol + water solution than a aaterial which was prepared in alkaline aediua. 

The solvent properties of alcohols with short carbon chains are similar to those of water and such alcohols could be used as the nonaqueous catalyst phase when the products are apolar in nature. The first commercial biphasic process, the Shell Higher Olefin Process (SHOP) developed by Keim et al. [4], is nonaqueous and uses butanediol as the catalyst phase and a nickel catalyst modified with a diol-soluble phosphine, R2PCH2COOH. While ethylene is highly soluble in butanediol, the higher olefins phase-separate from the catalyst phase (cf. Section 2.3.1.3). The dimerization of butadiene to 1,3,7-octatriene was studied using triphenylphosphine-modified palladium catalyst in acetonitrile/hexafluoro-2-phe-nyl-2-propanol solvent mixtures [5]. The reaction of butadiene with phthalic acid to give octyl phthalate can be catalyzed by a nonaqueous catalyst formed in-situ from Pd(acac)2 (acac, acetylacetonate) and P(0CeH40CH3)3 in dimethyl sulfoxide (DMSO). In both systems the products are extracted from the catalyst phase by isooctane, which is separated from the final products by distillation [5]. 

If a compound is poorly soluble in water, the pKa may be difficult to measure. One way around this problem is to measure the apparent pKa of the compound in solvent and water mixtures and then extrapolate the data back to a purely aqueous medium using a Yasuda-Shedlovsky plot. The organic solvents most frequently used are methanol, ethanol, propanol, dimethylsulphoxide (DMSO), dimethyl formamide (DMFA), acetone and tetrahydrofuran (THF). However, methanol is by far the most popular because its properties are closest to water. A validation study in water-methanol mixtures has been reported by Takacs-Novdk et al. (1997) and the determination of the pfCas of ibuprofen and quinine in a range of organic solvent-water mixtures has been reported by Avdeef et al. (1999). 

A great deal of work with different experimental and theoretical techniques has been performed in the past on characterizing liquid binary mixtures of simple alcohols with water [46,58-78]. Water mixtures with a short-chain alcohol up to 1-propanol [50,58-81], which mix with water over the whole concentration regime, have been studied the most extensively. Nevertheless, one can also find some similar studies with long-chain alcohols that are practically insoluble in water [46,76,77,82-86]. The motivation for such abundant work lies in the anomalous behavior of such mixtures. Namely, when simple alcohols are mixed with water the entropy of the system seems to increase far less than would be expected for an ideal solution of randomly mixed molecules [75]— a phenomenon that is also clearly expressed in the anomalous behavior of some other measurable properties. Furthermore, one can find two completely different concepts to explain these anomalous properties existing in the literature, which makes these binary mixtures even more intriguing nowadays. 

Propylene oxide is a colorless, low hoiling (34.2°C) liquid. Table 1 lists general physical properties Table 2 provides equations for temperature variation on some thermodynamic functions. Vapor—liquid equilibrium data for binary mixtures of propylene oxide and other chemicals of commercial importance ate available. References for binary mixtures include 1,2-propanediol (14), water (7,8,15), 1,2-dichloropropane [78-87-5] (16), 2-propanol [67-63-0] (17), 2-methyl-2-pentene [625-27-4] (18), methyl formate [107-31-3] (19), acetaldehyde [75-07-0] (17), methanol [67-56-1] (20), ptopanal [123-38-6] (16), 1-phenylethanol [60-12-8] (21), and / /f-butanol [75-65-0] (22,23). 

Flo. 19. Dependence of solVMt properties pertinent to RPC on composition of water-fl-propanol mixtures at 25 C, Sur ce tension y data were obtained from Tim mermans ilS4) the viscosity and dielectric constant c data were taken from Timmermans (134) and Aketlof (/id), respe vely. 

A mixture of benzene and methanol (19 to 1) was used for spreading the alkyl phosphonates. To minimize the influence of benzene on the film properties, the concentrations of the spreading solutions were > 1.5 X 10 3 gram per ml., and the experiments were performed at tt > 4 dynes per cm. (25). Moreover, higher proportions of methanol in the spreading solution did not alter the film properties under study for selected monolayers. For the sulfates, a mixed solvent containing water-benzene-2-propanol (1 10 10) was used because with the benzene-methanol solutions the properties of the films depended on the age of solution from which the films were prepared. Stearic and palmitic acids were spread from either hexane or the benzene-methanol solvent used for the phosphonates. Identical desorption results were obtained with the two solvents. 

Fig. 6.25. Effect of the percentage of 1-propanol in the porogenic mixture on the porous properties of monolithic polymers (Reprinted with permission from [64], Copyright 1998 American Chemical Society). Reaction conditions polymerization mixture ethylene dimethacrylate 16.00 wt.%, butyl methacrylate 23.88 wt.%, 2-acrylamido-2-methyl-l-propanesulfonic acid 0.12 wt.%, ternary porogen solvent 60.00 wt.% (consisting of 10 wt.% water and 90 wt.% of mixtures of 1-propanol and 1,4-butanediol), azobisisobutyronitrile 1 wt.% (with respect to monomers), polymerization time 20 h at 60°C.

The data in Table 1 show that clustering occurs in the water-rich region of solutions of propanols and tert-butyl alcohol, for alcohol molar fractions <0.3—0.4. Numerous models have been suggested to explain the properties of water-alcohol mixtures. They can be roughly subdivided in the following groups (a) Chemical models 29-33 qj) chemical equilibrium between clusters and the constituent components, which can explain some thermodynamic properties of these solutions, but involve... 

The 2-D TLC was successfully applied to the separation of amino acids as early as the beginning of thin-layer chromatography. Separation efficiency is, by far, best with chloroform-methanol-17% ammonium hydroxide (40 40 20, v/v), n-butanol-glacial acetic acid-water (80 20 20, v/v) in combination with phenol-water (75 25, g/g). A novel 2-D TLC method has been elaborated and found suitable for the chromatographic identification of 52 amino acids. This method is based on three 2-D TLC developments on cellulose (CMN 300 50 p) using the same solvent system 1 for the first dimension and three different systems (11-IV) of suitable properties for the second dimension. System 1 n-butanol-acetone -diethylamine-water (10 10 2 5, v/v) system 11 2-propanol-formic acid-water (40 2 10, v/v) system 111 iec-butanol-methyl ethyl ketone-dicyclohexylamine-water (10 10 2 5, v/v) and system IV phenol-water (75 25, g/g) (h- 7.5 mg Na-cyanide) with 3% ammonia. With this technique, all amino acids can be differentiated and characterized by their fixed positions and also by some color reactions. Moreover, the relative merits of cellulose and silica gel are discussed in relation to separation efficiency, reproducibility, and detection sensitivity. Two-dimensional TLC separation of a performic acid oxidized mixture of 20 protein amino acids plus p-alanine and y-amino-n-butyric acid was performed in the first direction with chloroform-methanol-ammonia (17%) (40 40 20, v/v) and in the second direction with phenol-water (75 25, g/g). Detection was performed via ninhydrin reagent spray. 

Results and Discussion. Figure 14 demonstrates the principal of separation through Ion-exchange membranes, where the counter-lon/permeate Interactions determine the mass transport properties of the system. In this set of experiments, the feed mixture was an azeotropic composition of 2-propanol and water (88.5/11.5 wt.X). A Naflon hollow fiber permeator was used In pervaporatlon mode. The... 

Here Y denotes a general bulk property, Tw that of pure water and Ys that of the pure co-solvent, and the y, are listed coefficients, generally up to i=3 being required. Annotated data are provided in (Marcus 2002) for the viscosity rj, relative permittivity r, refractive index (at the sodium D-line) d. excess molar Gibbs energy G, excess molar enthalpy excess molar isobaric heat capacity Cp, excess molar volume V, isobaric expansibility ap, adiabatic compressibility ks, and surface tension Y of aqueous mixtures with many co-solvents. These include methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-2-propanol (tert-butanol), 1,2-ethanediol, tetrahydrofuran, 1,4-dioxane, pyridine, acetone, acetonitrile, N, N-dimethylformamide, and dimethylsulfoxide and a few others. 

Type I mixtures have continuous gas-liquid critical line and exhibit eomplete miseibil-ity of the liquids at all temperatures. Mixtures of substances with eomparable eritieal properties or substances belonging to a homologous series form Type I unless the size difference between components is large. The critical locus could be convex upward with a maximum or concave down with a minimum. Examples of Type I mixtures are Water -l-1-propanol, methane -i- n-butane, benzene -I- toluene, and carbon dioxide -I- n-butane. 

---