摘要:
A process for the rearrangement of polyorganosiloxanes using solid sulfonated polyethylene as a rearrangement catalyst. The process comprises contacting polyorganosiloxanes at a temperature within a range of about 20.degree. C. to 110.degree. C. with a rearrangement catalyst consisting essentially of a solid sulfonated polyethylene. In a preferred process, the solid sulfonated polyethylene is in the form of hollow fibers through which the polyorganosiloxanes are passed to effect rearrangement.
摘要:
A membrane of defined pore structure and controlled pore diameter and a method of preparing the membrane which comprises dispersing in a water soluble polymer solution (A) an organic polymer solution (B), the water-soluble polymer solution (A) being a non-solvent for the polymer solution (B), to form micro-spherical droplets of the polymer solution (A) which are enveloped by a solid phase consisting of a coagulated or cross-linked polymer solution (B); evenly casting the dispersion on a flat surface; and evaporating the solvent for the polymer solution (B) to form a microporous membrane comprised of the polymer (B), the porosity, pore size, and void volume of the microporous membrane being a function of the polymer (A) concentration, the microsphere dimensions and the temperature and evaporation rate. The water-soluble polymer (A) is selected from polyethyleneimine, gelatin, polyvinyl-pyrrolidone, polyvinyl pyridinium halide, polyacrylic acid, polyhydroxyethylmethacrylate (HEMA), dextran, or polyvinyl acetate. The continuous phase polymer (B) is selected from a brominated polyphenylene oxide, polyphenylene oxide, polyacetic acid, polystyrene, polyglycol acrylate (PGA), polymethylmethacrylate, cellulose acetate, polyvinyl acetate, polycarbonate and polyvinylidene fluoride.
摘要:
A membrane permeation process for dehydrating a mixture of organic liquids, such as alcohols or close boiling, heat sensitive mixtures. The process comprises causing a component of the mixture to selectively sorb into one side of sulfonated ion-exchange polyalkene (e.g., polyethylene) membranes and selectively diffuse or flow therethrough, and then desorbing the component into a gas or liquid phase on the other side of the membranes.
摘要:
The present disclosure relates to improved polymeric materials and to a process for preparing same, which comprises blending suitable polymers into novel polymeric alloys. The disclosure further relates to novel fire-retarding and flame-resistant materials comprising such polymeric alloys and to novel membrane materials and membranes, adapted to provide novel processes of separation based on membrane technology. The novel polymeric alloys comprise commercially available polymers, blended with novel polymeric phosphonates of the general formula: ##STR1## WHEREIN: M, M', N, N' ARE ZERO OR ANY INTEGER, P IS AN INTEGER HIGHER THAN 10X designates a hydrogen atom halogen atom or a phosphorusContaining groupY designates a CH.sub.2 CHCl or CH.sub.2 CCl.sub.2 groupZ and Z' designates H or a phosphonate group - PO(OR') (OR") (at least one being a phosphonate group), wherein R and R' are alkyl or aryl groups.
摘要:
Solid polymer membranes comprised of a high charge density sulfonated poly (phenylene oxide) blended with poly(vinylidene fluoride) in varied ratios have improved membrane characteristics. These membranes are inexpensive and possess very high ionic conductivity, and thus are suitable for solid polymer electrolytes in electrochemical applications, especially for the polymer electrolyte membrane (PEM) fuel cell, the electrolyte double-layer capacitor, and the rechargeable zinc-halide cell. These membranes enhance the performance of these devices.
摘要:
Solid polymer membranes comprised of a high charge density sulfonated poly (phenylene oxide) blended with poly(vinylidene fluoride) in varied ratios have improved membrane characteristics. These membranes possess very high ionic conductivity, are inexpensive and suitable for solid polymer electrolytes in electrochemical applications, especially for the polymer electrolyte membrane (PEM) fuel cell. PEM fuel cell assemblies with this membrane have enhanced performance.
摘要:
Composite membranes suitable for separating gas mixtures are made by in situ crosslinking of aminoorganofunctional polysiloxane, 1 to 9 mol percent aminosiloxane units, with diisocyanate on the surface of a highly porous polymer substrate, such as polysulfone. Using the crosslinked polysiloxane as a gutter layer, a gas separating entity can be coated on the gutter layer to make a double layer composite membrane which has a higher separation factor than the crosslinked polysiloxane and can be used effectively for flat sheet membranes, as well as, hollow fiber membranes.
摘要:
Polymer alloys of a phosphorus-containing polymer component having the formula: ##STR1## WHEREIN X is hydrogen or halo; Z and Z' are each hydrogen or a phosphonate group PO(OR)(OR.sub.1) in which R and R.sub.1 are each alkyl or aryl, but are not both hydrogen, Y is a bivalent radical from an ethylenically unsaturated monomer copolymerized with styrene, and m, m', n, n' and p are zero or integers as specified; and a second polymer component compatible with and alloyed with the phosphorus-containing polymer component, the second component being a cellulose ester, or a polystyrene or unsaturated polyester resin. Polymer alloys thus constituted are particularly useful as fire-retardant and flame-resistant materials, and as membranes useful in the separation of solvents exhibiting differential permeabilities therethrough.