Tetrahydrofuran solubility parameter

A more interesting example is given with PVC and the polycarbonate of bis-phenol A, both slightly crystalline polymers. It is noticed here that whilst methylene dichloride is a good solvent and tetrahydrofuran a poor solvent for the polycarbonate the reverse is true for PVC yet all four materials have similar solubility parameters. It would seem that the explanation is that a form of hydrogen bonding occurs between the polycarbonate and methylene dichloride and between PVC and tetrahydrofuran (Figure 5.7). In other words there is a specific interaction between each solvent pair. 

The solubility parameter is about 19.2MPa and being amorphous they dissolve in such solvents as tetrahydrofuran, mesityl oxide, diacetone alcohol and dioxane. Since the main chain is composed of stable C—C and C—O—C linkages the polymer is relatively stable to chemical attack, particularly from acids and alkalis. As already mentioned, the pendant hydroxyl groups are reactive and provide a site for cross-linking. 

As the data in Table 4.3 show, the solubility parameter reflects how a chemist might rank these solvents in terms of polarity, e.g. water as the most polar (highest 5) and hexane as the least polar (lowest 8) but also one of the difficulties with this measurement of polarity is highlighted. The solubility parameter suggests that tetrahydrofuran (THE) and carbon tetrachloride are very similar even though carbon tetrachloride is immiscible with water whilst THE is miscible with water in all proportions. A similar comparison may be made between chloroform (8 = 19.1, water-immiscible) and acetone (8 = 20.2, water-miscible). 

FIGURE 3 The dependences of macromolecular coil fractal dimension on polymer and solvent solubility parameters difference A5 for copolymers SAN-MMA. The solvents 1— toluene, 2—ethyl benzene, 3— benzene, 4—chlorobenzene, 5—chloroform, 6—tetrahydrofuran, 7—pyridine, 8—methyl ethyl ketone, 9-1,4-dioxane, 10—N, N-dimethylformamide. The same conventional signs are used in Figs. 4-11. 

The authors [97] proposed the Eq. (82) for the dimension 8 evaluation with using the solvent 8 and polymer 8 solubility parameters. The calculation according to this equation has shown that for star-like PS-Cg 8 value changes from 9.78 (cal/cm ) fgj- usual PS in tetrahydrofuran solution up to 30.7 (cal/cm ) 2 for star-like PS-C with 22 beams in chloroform solution. It is obvious, that the effective 8 value characterizes polymer dissolution complication at dimension Z) growth or macromolecular coils densification. In Fig. 106 the dependence 8 (e) is adduced, from which the... 

The values a for seven polyarylates of different chemical structure, obtained by high-temperature (equilibrium) and interfacial polycondensation, determined in three solvents (sirmn-tetrachloroethane, tetrahydrofuran and 1,4-dioxane) are accepted according to the data of work [53]. The fractal dimension Dj. experimental values (o ) in the indicated solvents were determined according to the Eq. (4). The values of solubility parameter s for these solvents are taken from hterary sources [25, 36, 56]. The fractal dimension 5 of solvent molecules stracture was determined according to the equation [71] ... 

Figure 3.27 Dependence of equilibrium swelling on the solubility parameter in a number of solvents (I) diethyl ether (II) diethylene glycol diethyl ether (III) butyl acetate (IVO ethyl acetate (V) tetrahydrofuran (VI) dioxane. Pohoirethane networks based on PTMG and PPG mixture without additives (4) and containing various KEP-2 mass fractions (1) 1.5 x 10 " (3) 5 X 10 (2) 7.5 x 10 (5) 1.5 x 10...

An understanding of the solubility of polysulfones is important for applications in which the polymer must be dissolved, such as in coatings and membrane applications. Solubility of the three commercial polysulfones follows the order PSF > PES > PPSE All three polysulfones can be dissolved in a small number of highly polar solvents to form stable solutions at room temperature. NMP, DMAc, pyridine, and aniline are suitable solvents for polysulfones. Also 1,1,2-trichlorethane and 1,1,2,2-tetrachloroethane are suitable but are unattractive for health reasons. Because of the lower solubility parameter of PSF, it can also be dissolved in several less polar solvents such as tetrahydrofuran (THF), 1,4-dioxane, chloroform, dichloromethane, and chlorobenzene. Solvent choices for PES and PPSF are fewer because these polymers have a propensity to undergo solvent-induced crystallization in many solvents. 

PECA is soluble in several highly polar solvents including nitromethane, DMF, acetone, tetrahydrofuran, and acetonitrile. Donnelly and Pepper have presented a more complete list of solvents and non solvents for polymethyl, polyethyl, and poly-n-butyl cyanoacrylate. These authors calculated the solubility parameter of PECA to be 11.2. Water absorption by PECA at room temperature and 50% RH is negligible.""... 

Equation 2.42 illustrates that the polymer and the solvent mix when their solubility parameters are close and do not when they differ a lot. However, this is not always the case. For instance, polyethylene and 1,4-dioxane have similar solubility parameters but do not mix partly because of crystallinity of polyethylene. Poly(methyl methacrylate) dissolves well in tetrahydrofuran, although the solubility parameters are greatly different. Furthermore, Eq. 2.42 is always positive. It fails to describe specific interactions that may make x negative such as the hydrogen bonding. We should regard Eq. 2.42 as one of the possible ways to describe x for some polymer-solvent systems. 

Ethylene oxide/styrene block copolymers have been further free-radical copolymerized with other ethylenically unsaturated compounds such as methyl methacrylate and methacrylic acid in benzene, tetrahydrofuran, and dimethylformamide (176). Correlations were made between reactivity ratio and solvent dielectric constant, as well as between solubility parameters of reaction solvent and growing polymer chains with marked effects apparent. Gel permeation chromatography of diblock and triblock copolymers based on polystyrene and poly(ethylene oxide) has revealed interesting molecular characteristics (177). Such block copolymers have an amphiphilic character. In aqueous solution, the polymers form spherical micells with a polystyrene core and a poly(ethylene oxide) outer sheath. The investigations used an aqueous-methanolic solution and were able to ascertain block copolymer structures and to estimate the impurities in the diblock copolymer. 

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