Solvents phenol, storage

NFPA Health 3, Flammability 2, Reactivity 0 Storage Air and light-sensitive Uses Disinfectant solvent phenolic resins tricresyl phosphate ore flotation textile scouring organic intermediate mfg. of salicylaldehyde, coumarin, herbicides, antioxidants, dyes cosmetics ingred. surfactant... 

PTT is a rapidly crystallizing polymer. A melt-processed PTT tends to crystallize with a crystallinity of between about 15 and 30 wt%. It is therefore more difficult to dissolve in solvents commonly used for amorphous PET. Stronger solvents, such as hexafluoroisopropanol (HFIPA) or a 1 1 mixture of trifluo-roacetic acid and methylene chloride are typically used to dissolve PTT. However, HFIPA is a very expensive solvent for routine IV measurements, and methylene chloride is too volatile to maintain in a 1 1 mixture with trifluoroacetic acid at elevated temperatures or in prolonged storage. With care, a 60/40 mixture of phenol/tetrachloroethane can be used satisfactorily for IV measurement when it is heated to 110 °C to ensure complete dissolution of PTT [37],... 

When contaminated or held in storage at temperatures below 60°F (15.5°C), hindered phenols may tend to crystallize and fall from solution as relatively pure compounds. Often solvent dilution of hindered phenols can help to reduce the tendency of crystal dropout, but will not completely eliminate this problem. 

Selection of a suitable extraction procedure can increase the concentration of phenolic diterpenes relative to the plant material. In addition, undesirable components can be removed prior to adding extracts to foods. For example, chlorophylls present in plant material may reduce the light stability of food during storage. Several extraction techniques have been patented (Nakatani et al., 1984 Aeschbach and Philippossian, 1989) using solvents with different polarity, such as petrol ether, hexane, toluene, acetone, methanol and ethanol. To obtain tailored extracts, the successive use of different solvents has been applied. 

Film adhesives have to be strictly delimitated from adhesive tapes and adhesive strips (Sections 5.6 and 5.7). Mainly blocked two-component reactive adhesives (Section 3.1.4) are used raw materials. For transport and storage (at low temperatures) they are applied to a - nonadhesive - substrate. Prior to processing they are removed and then applied between the adherends (compounding) and cured under pressure and heat (Sections 3.1.4, 3.2.2 and 4.1.2). Special film adhesives (e.g., phenolic resin nitrile rubber) are also activated by suitable solvents. 

Phenolics. These are thin films, which form by evaporation of solvent followed by baking at, or greater than, 204 °C. Phenolics form a very strong, hard chemical and temperature-resistant film used for storage of strong acids and solvents. 

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