摘要:
Azeotropic or azeotrope-like compositions of the present technology include methyl chloride and at least one hydrofluorocarbon or hydrofluoro-olefin. In some examples, the at least one hydrofluorocarbon or hydrofluoro-olefin can be selected from the group consisting of 1,1,1,2-tetrafluoroethane and 1,3,3,3-tetrafluoropropene. The azeotropic or azeotrope-like compositions can be used as solvents or diluents in polymerization processes, including slurry polymerization processes.
摘要:
Disclosed is a process for making one isomer of CF3CH═CHCl. More particularly, the invention comprises the production of CF3C≡CCl and its selective reduction to cis-1-chloro-3,3,3-trifluoropropene (CF3CH═CHCl).
摘要:
The present invention discloses high purity E-1-chloro-3,3,3-trifluoropropene (1233zd(E)) and methods to produce the same. More specifically, the present invention discloses the methods of making 1233zd(E) essentially free of toxic impurities (e.g. 2-chloro-3,3,3-trifluoropropene (1233xf), chlorotetrafluoro-propene (1224), and 3,3,3-trifluoropropyne). The present invention further provides methods for making high purity 1233zd(E) with concentration of 1233xf and 1224 at or below 200 parts per million (ppm) and 3,3,3-trifluoropropyne impurities at or below 20 ppm. Formation of 1233xf impurity can be avoided if pure 1,1,1,3,3-pentachloropropane is used as a starting material. It was also found that formation of 1233xf is avoided if a liquid phase manufacturing process is used.
摘要:
Compositions and methods based on the use of fluoroalkene containing from 3 to 4 carbon atoms and at least one carbon-carbon double bond, such as HFO-1214, HFO-HFO-1233, or HFO-1354, having properties highly beneficial in solvent cleaning applications.
摘要:
Heat transfer systems, methods and compositions which utilize a heat transfer fluid comprising: (a) from about 30% to about 65% by weight of HFC-134a; (b) from about 0% to about 70% by weight of HFO1234ze; and (c) from about 0% to about 70% by weight of HFO-1234yf, provided that the amount of HFO-1234ze and HFO-1234yf in the composition together is at least about 35% by weight, with the weight percent being based on the total of the components (a)-(c) in the composition.
摘要:
This invention provides azeotrope-like compositions of 1,1,1,3,3-pentafluoropropane and water that are environmentally desirable for use as refrigerants, aerosol propellants, metered dose inhalers, blowing agents for polymer foam, heat transfer media, and gaseous dielectrics.
摘要:
The invention relates to the addition of &agr;-methyl styrene, isobutanol and/or isopropanol to reduce vapor pressure, improve k-factor, enhance the solubility of the blowing agent in the premix and/or improve the processing characteristics of polyurethane and polyisocyanurate closed-cell foams prepared with a blowing agent comprising a hydrofluorocarbon selected from the group consisting of 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, and mixtures thereof.
摘要:
A process for the purification of difluoromethane comprising: (a) subjecting a mixture comprising at least difluoromethane (HFC-32) and dichlorodifluoromethane (CFC-12) to a first distillation step in which a majority of either CFC-12 or HFC-32 is concentrated in a first distillate and a majority of the other component is concentrated in a first bottoms; and (b) subjecting the first distillate in step (a) to at least one additional second distillation step conducted at a different pressure in which a majority of the component concentrated in said first distillate is concentrated in a second bottoms and in which the other component is concentrated in a second distillate; and (c) recovering purified HFC-32 from one of said first or second bottoms.
摘要:
A method for separating water from a chemical mixture is provided. In the process of the invention, water is separated from a chemical mixture by contacting the chemical mixture with a water-soluble polymer.
摘要:
The invention provides a method for separating fluorocarbons from mixtures of fluorocarbon and hydrogen fluoride. In particular, the invention provides a method for separating fluorocarbons, such as pentafluoropropane, from azeotropic mixtures of the fluorocarbon and hydrogen fluoride using compositional variations with pressure.