Solvent hot water

The physical behavior of an antioxidant is a major factor affecting its permanency, efficiency, and acceptability, especially when the polymer (e.g., fibers, films) artifact is placed directly in contact with aggressive environments, e.g., organic solvents including dry cleaning solvents, hot water and detergents, hot oils, acids, fatty food, hot air, and intense solar radiation. Physical factors, which control the permanence and efficacy of an antioxidant include distribution, solubility, diffusivity, volatility, and leachability. 

Pd-Cu alloy coated plastic samples were first cut into discs 75 mm in diameter, sandwiched together with a porous metal disc (Monel) between two microscreens and then clamped (refer to schematic in Fig. 11.2). To remove the plastic backing material, the samples are then lowered horizontally with the coated polymer discs up. Monel mesh down, into the appropriate solvent hot water (60-80°C) for Solublon and chloroform (room temperature) for polystyrene. Polymer dissolution (removal rate) was evaluated as a function of temperature and time. Nominal times were 30 s for the Solublon and 600 s for the polystyrene. Upon dissolution of the polymer backing material, samples were removed from the solvent, carefully disassembled and then dried. 

An analysis of propellant containing nitroguanidine will be more difficult, nitroguanidine being insoluble in these solvents. Hot water will, however, dissolve nitroguanidine from the propellant. 

With a blend of solvents (hot water, extran 20% (v/v), acetone/water 1 1 (v/v) and aqueous NaOH 10% (w/v)), a weight loss of 41.49% was observed with respect to the initial weight of the fiber. Different types of extractives were removed with each treatment step according to their solubility. According to lozzi et al. [25], extran removes fats, oils, saponins and other similar compoimds. Acetone and water remove excessive impurities that may be present at the fiber surface. 

If crystallisation commences as soon as the solvent cools or if large quantities of hot solution are to be filtered, the funnel (and fluted filter paper) should be warmed externally during the filtration (hot water funnel). Three types of hot water funnel are illustrated in Fig. 11,1, 6 no flames should be present whilst inflammable solvents are being filtered through the funnel of Fig. 11, 1, 6, a. Alternatively, the funnel may be surrounded by an electric heating mantle (see Section 11,57) the heat input may be controlled by a variable transformer. When dealing with considerable volumes of aqueous or other solutions which do not deposit crystals rapidly on cooling, a Buchner funnel may be used for filtration (see detailed account in Section 11,1 and Fig. 11 1, 7, c). The filter paper... 

Dissolve 5 g. of phenol in 75 ml. of 10 per cent, sodium hydroxide solution contained in a wide-mouthed reagent bottle or conical flask of about 200 ml. capacity. Add 11 g. (9 ml.) of redistilled benzoyl chloride, cork the vessel securely, and shake the mixture vigorously for 15-20 minutes. At the end of this period the reaction is usually practically complete and a sohd product is obtained. Filter oflf the soUd ester with suction, break up any lumps on the filter, wash thoroughly with water and drain well. RecrystaUise the crude ester from rectified (or methylated) spirit use a quantity of hot solvent approximately twice the minimum volume required for complete solution in order to ensure that the ester does not separate until the temperature of the solution has fallen below the melting point of phenyl benzoate. Filter the hot solution, if necessary, through a hot water funnel or through a Buchner funnel preheated by the filtration of some boiling solvent. Colourless crystals of phenyl benzoate, m.p. 69°, are thus obtained. The yield is 8 g. 

Section IV,49). Reflux the mixture for 1 hour and allow to cool, with continuous stirring. Distil off the methyl alcohol. Add hot water to the residue, filter from impurities, extract the antipyrine with benzene, and evaporate the solvent. RecrystaUise the crude product from benzene or benzene - hght petroleum or from hot water wdth the addition of a little decolomising carbon. The yield of antipyrin (white crystalline solid, m.p. 113°) is 3o g. 

DMSO - Dimethylsulphoxide is a very common solvent with a freezing point of 20 degrees. When you buy this stuff it will be crystallised in the bottle. To melt, all you need to do is place the bottle in a bowl of hot water for 30 minutes - simple. If you re lucky enough to live somewhere warm it may already be liquid, where I live, no chance. When you open the bottle you will notice that this stuff smells a bit farty, don t worry too much, it doesn t get that bad. 500ml straight into the reaction flask and start the stirrer. 

TBPA is prepared in high yield by the bromination of phthalic anhydride in 60% oleum (51). The use of oleum as the bromination solvent results in some sulfonation of the aromatic ring (52). Sulfonated material is removed by hydrolyzing the anhydride with dilute NaOH, filtering and acidifying with dilute HCl. The precipitated acid is washed several times with hot water and reconverted to the anhydride by heating at 150°C for several hours. 

A process has been developed (139) whereby up to 80% of the oil can be removed from whole, raw peanuts without the use of solvent. In this process, the blanched peanuts are brought to a proper moisture content, pressed mechanically, and then reshaped or reconstituted by dipping in hot water subsequently they can be roasted and salted, or used in confections or other formulations. Defatted peanuts may also be ground into meal and added to cookies, cakes, and many other products, where they impart a distinctly nutty flavor and cmnchy texture. On the other hand, the resulting high grade oil is refined and employed in cooking and industrial products. This process can also be used for pecans, walnuts, almonds, Brazil nuts, cashews, and other nuts (140-142). 

The use of supercritical and hot water as a solvent is still largely experimental. Because supercritical technology is well known in the power industry, this use of water is likely to increase in the future. Corrosion control may be an important limiting consideration. General process economics are the second potential limit (see SUPERCRITICAL FLUIDS). 

Hydration and Dehydration. Succinic anhydride reacts slowly with cold water and rapidly with hot water to give the acid. For this reason it must be carefully stored in anhydrous conditions. Succinic acid can be dehydrated to the anhydride by heating at 200°C, optionally in the presence of a solvent (31). Dehydration can also be performed with clay catalysis in the presence of isopropenyl acetate under microwave irradiation (32) or with his (trichi oromethyl) carbonate at room temperature (33). 

Unlike HEC and CMC, which are purified by washing with aqueous organic solvents, methylceUulose and its hydroxyalkyl modifications are purified in hot water where they are insoluble. As with other cellulose ethers, drying and grinding complete the process. 

Benzyl chloride [(chloromethyl)henzene, a-chlorotoluene], CgH CH2Cl, is a colorless Hquid with a very pungent odor. Its vapors are irritating to the eyes and mucous membranes, and it is classified as a powerfljl lacrimator. The physical properties of pure benzyl chloride are given in Table 2 (2—7). Benzyl chloride is insoluble in cold water, but decomposes slowly in hot water to benzyl alcohol. It is miscible in all proportions at room temperature with most organic solvents. The flash point of benzyl chloride is 67°C (closed cup) 74°C (open cup) autoignition temperature is 585°C lower flammability limit 1.1% by volume in air. Its volume coefficient of expansion is 9.72 x. ... 

Lamination. la lamination a film is prepared by caleaderiag or extmsioa (see Laminated materials, plastic). It is thea adhered to a textile at a laminator by either an adhesive or sufficient heat which partially melts the film to obtain a mechanical bond. There are a variety of adhesives available for lamination, including solvent systems, water-base latex systems, and various forms of hot melt adhesives (qv). 

With knitted fabrics it is necessary to remove the knitting oils by either alkaH treatment or solvents. Where water-immiscible oils have been used and the fabric is to be hot dyed (80°C or above), a minimum scour to remove dirt and stains can be sufficient, the rest of the oil being removed during the dyeing process. 

From the data reported in (63PMH(l)177) it was concluded that hydrophobic substituents reduce the solubility of pyrazole in water (at 20 °C pyrazole, 1 part in 2.5 3,5-dimethyl-pyrazole, 1 part in 52). Another determination gives the following values for the solubilities of pyrazole at 25 °C in water, benzene and cyclohexane (expressed as g/100 g of solvent) 130, 18 and 3 (66AHC(6)347). Indazole is soluble in hot water and most organic solvents, but less so in cold water. 

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