Solvent-free compositions

A typical EB curable formulation will generally consist of a relatively high molecular weight solid or semi-solid difunctional acrylic resin reduced to application viscosity with combinations of liquid mono- and multifunctional acrylic monomers. These acrylic monomers, along with a few other selected polymerizable monomers, serve as reactive diluents and allow formulation of solvent-free compositions. Usually, small amounts of additives are also used in order to provide special properties, such as slip. 

Structural adhesives are solvent-free compositions and can be formulated to give varying pot-lives, making them suitable for temperate as well as tropical climatic conditions. A long pot-life makes the adhesive suitable for use with form work or where additional steel reinforcement has to be fitted. 

Adhesives and sealants are manufactured from a variety of polymers. Their selection and their combinations used impact solvent selection. Most solvent systems are designed to optimize the solubility of the primary polymer. Adhesives can be divided into ones which bond by chemical reaction and ones which bond due to physical processes. Chemically reactive adhesives are further divided into three more categories for those that bond through polymerization, polyaddition, or polycondensation. Physically bonding adhesives include pressure sensitive and contact adhesives, melt, or solution adhesives, and plastisols. Polymerization adhesives are composed of cyanoacrylates (no solvents), anaerobic adhesives (do not contain solvents but require primers for plastics and some metals which are solutions of copper naphthenate), UV-curable adhesives (solvent-free compositions of polyurethanes and epoxy), rubber modified adhesives (variety solvents discussed below). 

Removal of fhe solvent from the raffinate and extract, which can (for example) be accomplished by distillation, results in the solvent-free compositions located at R and These points lie on the straight-line extrapolations of RB and EB, as required by the mixing rule. We note in addition that a maximmn in the solute concentration results when the product extract is located on the tangent drawn through B to the solubility cmve, leading to point Es. 

If 1000 kg/h of a cottonseed oil-oleic acid solution containing 25% acid is to be continuously separated into products containing 2 and 90% acid (solvent-free compositions) by countercurrent extraction with propane, make the foUowing computations on the coordinate tems of parts (a) and (b) of Prob. 10.12 ... 

Analysis of current patents shows that solvents are still important components of technology in aerospace applications. Solvent-based primer modifies the smface of the rigid substrate and then contributes to chemical bonding. Many applications of materials require that they are solvent resistant, when solvents are used for cleaning, jointing, or other purposes. Environmentally safe solvent compositions are also actively piusued and solvent-free compositions are developed." ... 

CHUN, S.W., XIANG, W.Z., APPLEBY, A.J., Solvent-free composite PEO-ceramic fiber/mat electrolytes for hthium secondary cells, J. Electrochem. Soc., 2005, 152(1), 205-9. 

Several patents describe solvent-free bulk-phase halogenation (67—69). Dry soHd butyl mbber is fed into a specially designed extmder reactor and contacted with chlorine or bromine vapor. The by-product HCl or HBr ate vented directly without a separate neutralization step. Halogenated butyl mbbers produced are essentially comparable in composition and properties to commercial products made by the solution process. 

High Solids Costings. High soHds coatings resemble the technology of solvent-free coatings but the compositions contain ca 70% by volume of soHd resin and are modified by reactive diluents, low viscosity multifunctional resins, or backbone stmctures other than the bisphenol A moiety. 

There are different ways in which the nanoparticles prepared by ME-technique can be used in catalysis. The use of ME per se [16,17] implies the addition of extra components to the catalytic reaction mixture (hydrocarbon, water, surfactant, excess of a metal reducing agent). This leads to a considerable increase of the reaction volume, and a catal5fiic reaction may be affected by the presence of ME via the medium and solubilization effects. The complex composition of ME does not allow performing solvent-free reactions. 

A primary role of crystallization is to purify the desired product and exclude impurities. Such impurities are frequently related in chemical structure to the desired product, through the mechanisms of competitive reaction and decomposition. Where the impurities are similar in structure it is likely that their interactions with the solvent in the liquid phase will also be similar. In this instance the selectivity of crystallization is mainly attributed to the difference between the respective pure solid phases. The ideal solubility equation can be applied to such systems [5, 8] on a solvent free basis to predict the eutectic composition of the product and its related impurities. The eutectic point is a crystallization boundary and fixes the available yield for a single crystallization step. 

Raman often is evaluated as an alternative to an existing high performance liquid chromatography (HPLC) method because of its potential to be noninvasive, fast, simple to perform, and solvent-free. Raman was compared to HPLC for the determination of ticlopidine-hydrochloride (TCL) [43], risperidone [44] in film-coated tablets, and medroxyprogesterone acetate (MPA) in 150-mg/mL suspensions (DepoProvera, Pfizer) [45] it was found to have numerous advantages and performance suitable to replace HPLC. In an off-line laboratory study, the relative standard deviation of the measurement of the composition of powder mixtures of two sulfonamides, sulfathiazole and sulfanilamide, was reduced from 10-20% to less than 4% by employing a reusable, easily prepared rotating sample cell [46]. 

Rn = composition of solvent-free raffinate from nth theoretical stage... 

Bj = composition of solvent-free extract from first theoretical stage (no reflux)... 

E = composition of extract (solvent-free) from treater with reflux... 

The composition of mixed solvent (free of salt) was calculated from the amounts of methanol and water before mixing. The reproducibility of the preparation of the mixed solvent was within 0.001 mole fraction over the whole composition range. 

Figure 13.23. Examples of vapor-liquid equilibria in presence of solvents, (a) Mixture of-octane and toluene in the presence of phenol, (b) Mixtures of chloroform and acetone in the presence of methylisobutylketone. The mole fraction of solvent is indicated, (c) Mixture of ethanol and water (a) without additive (b) with 10gCaCl2 in 100 mL of mix. (d) Mixture of acetone and methanol (a) in 2.3Af CaCl2 ip) salt-free, (e) Effect of solvent concentration on the activity coefficients and relative volatility of an equimolal mixture of acetone and water (Carlson and Stewart, in Weissbergers Technique of Organic Chemistry IV, Distillation, 1965). (f) Relative volatilities in the presence of acetonitrile. Compositions of hydrocarbons in liquid phase on solvent-free basis (1) 0.76 isopentane + 0.24 isoprene (2) 0.24 iC5 + 0.76 IP (3) 0.5 iC5 + 0.5 2-methylbutene-2 (4) 0.25-0.76 2MB2 + 0.75-0.24 IP [Ogorodnikov et al., Zh. Prikl. Kh. 34, 1096-1102 (1961)].

Other nomenclature is identified on the flowsketch. The solvent-free reflux point R0 s located on the extension of line SEx. Operating point Q is located at the intersection of lines SRC and RnM. Lines through Q intersect the binodal curve in compositions of raffinate and reflux related by material balance for instance, R and E +l. When the line QF is crossed, further constructions are... 

The melt used in this work was prepared from the residue of hydrogen-donor extraction of Colstrip coal with tetralin solvent in such a way as to simulate the composition of an actual spent melt. The extraction was conducted in the continuous bench-scale unit previously described (17) at 412°C and 50 min residence time. The residue used was the solvent-free underflow from continuous settling (17) of the extractor effluent. The residue was then precarbonized to 675°C in a muffle furnace. The melts were blended to simulate the composition of a spent melt from the direct hydrocracking of the Colstrip coal by blending together in a melt pot zinc chloride, zinc sulfide, and ammonium chloride, ammonia, and the carbonized residue in appropriate proportions. Analysis of the feed melt used in this work is given in Table I. 

Tie lines of the system can be generated from the equilibrium compositions for each run and selectivities computed. The results of measurements obtained for the 5% by volume of ammonia/ethylene are represented in the binodal diagram in Fig. 3. Butene is represented as the distributed component between the solvent phase and the butadiene-rich phase. The ammonia-solvent gas mixture was considered to behave as a pseudo-solvent of fixed composition. The ratio of the integrated peaks for butene(i) and butadiene(j) was used to compute the selectivity, B (beta), defined on a solvent-free basis, as ... 

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