Abstract:
A microporous, polymeric film is prepared by dissolving methylene-chloride-soluble, film-forming polymers completely in methylene chloride. Then an aqueous phase is prepared containing non-methylene-chloride-soluble, water-soluble thickeners and, if desired, additives, and brought to a viscosity of about 0.07 to 0.5 Pa s. The aqueous phase is then dispersed in the polymer solution and the resultant paste is spread onto a support material or intermediate support, the methylene chloride is evaporated, the resultant membrane is transferred to the actual support, and finally the water is removed by drying.
Abstract:
AN AQUEOUS LATEX COATING COMPOSITION ADAPTED TO DEPOSIT FILMS WHICH DRY TO FORM A CELLULAR LAYER OF HIGH OPACITY IS PROVIDED BY SWELLING THE RESIN PARTICULES OF THE AQUEOUS LATEX WITH A PRIMARY ORGANIC SOLVENT WHICH IS ESSENTIALLY IMMISICIBLE IN THE AQUEOUS PHASE OF THE LATEX SUCH AS XYLENE, AND BY INTRODUCING INTO THE AQUEOUS PHASE AN AT LEAST PARTIALLY WATER MISCIBLE ORGANIC SOLVENT, SUCH AS PROPYLENE GLYCOL, HAVING A LOWER EVAPORATION RATE AND A LESSER CAPACITY FOR SOLVATING THE RESIN OF THE LATEX THAN SAID PRIMARY SOLVENT. WHEN THE PRIMARY SOLVENT EVAPORATES, A CELLULAR FILM IS FORMED, THE SECONDARY SOLVENT SERVING TO INCREASE THE OPACIFICATION WHICH IS OBTAINED. PARTICULATE MATTER OR MATERIAL WHICH CRYSTALLIZES TO FORM PARTICULATE MATTER IS INCORPORATED INTO THE LATEX IN SMALL AMOUNT. THE PARTICULATE MATTER SERVES TO INCREASE ULTIMATE OPACITY AND ALSO TO GENERATE OPACITY MORE RAPIDLY WHEN A DEPOSITED FILM IS DRIED.
Abstract:
THE DISCLOSED INVENTION RELATES TO IMPROVED OPAQUE FILMS WHICH ARE CONTINUOUS, MICROCELLULAR AND NON-POROUS POSSESSING UNUSUAL HIDING ABILITY AND OPACITY. THE FILMS OF THIS INVENTION ARE PREPARED FROM A NOVEL LATEX MIXTURE COMPRISING: NON-ELASTOMERIC POLYMERIC MATERIAL, WATER, NON-SOLVENT FOR THE POLYMERIC MATERIAL IN A WEIGHT RATIO OF NON-SOLVENT TO POLYMER SOLIDS OF ABOUT 0.05 TO ABOUT 3:1.0 AND AN OPACIFYING PIGMENT IN A WEIGHT RATIO OF PIGMENT TO POLYMER SOLIDS OF FROM ABOUT 0.1 TO ABOUT 5:1. THE NON-SOLVENT IS SELECTED SUCH THAT IT HAS A BOILING POINT RANGE ABOVE THAT OF WATER AND HAVING SUFFICIENTLY LOW VOLATILITY TO REMAIN ENTRAPPED IN THE POLYMERIC MATRIX WHEN THE COMPOSITION HAS REACHED A QUASI-RIGID OR TACKFREE STATE WHEN APPLIED AS A FILM. ONCE THE FILM HAS BECOME TACK-FREE THE NON-SOLVENT IS EVAPORATED SO AS TO LEAVE BEHIND MINUTE, CLOSED CELLS WHICH ENHANCE THE HIDING AND OPACITY OF THE FILM. THE DISCLOSED INVENTION ALSO RELATES TO OPAQUE FILMS WITH ENHANCED OPTICAL PROPERTIES PRODUCED BY THE INCLUSION OF COLORED PIGMENTS, DYES FLUORESCENT MATERIALS AND OPTICAL BRIGHTENERS IN THE UNUSUALLY OPACIFIED FILMS IN SUCH A MANNER AS TO MAXIMIZE THEIR EFFECTIVE NESS THEREIN.
Abstract:
THE DISCLOSED INVENTION RELATES TO FILMS FROM A NOVEL LATEX MIXTURE WHICH ARE NON-POROUS, MICROCELLULAR AND OPAQUE IN THE ABSENCE OF AN OPACIFYING AGENT. THE PREPARATION OF THE FILMS OF THE DISCLOSED INVENTION COMPRISES PROVIDING CONTROL TECHNIQUES FOR ENTRAPPING A SUFFICIENT AMOUNT OF A LIQUID NON-SOLVENT FOR THE POLYMER IN THE POLYMER MATRIX OF A LATEX AFTER THE CONTINOUS PHASE REMOVAL, SO THAT UPON EVAPORATION OF THE NONSOLVENT FROM A COALESCED AND TACK-FREE POLYMER MATRIX, A RESULTING OPAQUE
AND CONTINUOUS, NON-POROUS FILM IS PRODUCED WHICH WILL HAVE MINUTE, DISCRETE AND SUBSTANTIALLYCLOSED VOIDS AND WHICH IS OPAQUE IN THE ABSENCE OF AN OPACIFYING AGENT SUCH AS PIGMENT. THE DISCLOSED INVENTION ALSO RELATED TO OPAQUE FILMS WITH ENHANCED OPTICAL PROPERTIES PRODUCED BY THE INCLUSION OF PIGMENTS, FLORESCENT MATERIALS AND OPTICAL BRIGHTENERS IN THE OPAQUE FILMS IN SUCH A MANNER AS TO MAXIMIZE THEIR EFFECTIVENESS THEREIN.
Abstract:
The present invention relates to a process for preparing a porous material, at least comprising the steps of providing a mixture (I) comprising a composition (A) comprising components suitable to form an organic gel and a solvent (B), reacting the components in the composition (A) in the presence of the solvent (B) to form a gel, and drying of the gel obtained in step b), wherein the composition (A) comprises a catalyst system (CS) at least comprising a catalyst component (C1) selected from the group consisting of ammonium salts and a carboxylic acid as catalyst component (C2). The invention further relates to the porous materials which can be obtained in this way and the use of the porous materials as thermal insulation material and in vacuum insulation panels and vacuum insulation systems, in particular in interior or exterior thermal insulation systems as well as for the insulation of refrigerators and freezers and in water tank or ice maker insulation systems.
Abstract:
A solid-phase synthesis carrier, a preparation method therefor and the use thereof, wherein a diene cross-linking agent with a similar reactivity ratio to styrene and two vinyl groups thereof not on the same benzene ring is selected as a cross-linking monomer, and is subjected to suspension polymerization to obtain a porous resin. The porous resin is then functionalized to obtain a porous resin with an amino or hydroxyl functional group. Compared with existing preparation methods, the reactivity ratio of the cross-linking agent and styrene is similar, which is beneficial to improving the uniformity of the chemical structure in the resin, forming uniformly distributed active sites and channels, and is beneficial to improving the reaction efficiency and reducing the mass transfer resistance. The preparation of oligonucleotides by using such a carrier as a solid-phase synthesis carrier can improve the yield and purity of the oligonucleotides.
Abstract:
A method of making a porous material is provided. The method includes: preparing a mixture including a sugar, a polymer, and at least one soluble metal source, in water; heating the mixture to obtain a gelled material; thermally curing the gelled material to obtain a cured material; and annealing at least a part of the cured material to obtain a porous material that includes metal nanoparticles, where the metal nanoparticles include at least one metal from the at least one soluble metal source. The porous material can include: sheets of multilayer graphene layers; metal nanoparticles dispersed among the sheets and encapsulated by layers of graphene; and macropores, mesopores or micropores, or any combination thereof, throughout the porous material and on its surface. Methods of using the porous material to separate contaminants from water are also provided.
Abstract:
The present invention relates to a process for preparing a porous material, at least comprising the steps of providing a mixture (I) comprising a water soluble polysaccharide, at least one compound suitable to react as cross-linker for the polysaccharide or to release a cross-linker for the polysaccharide, and water, and preparing a gel (A) comprising exposing mixture (I) to carbon dioxide at a pressure in the range of from 20 to 100 bar for a time sufficient to form a gel (A), and depressurizing the gel (A). Gel (A) subsequently is exposed to a water miscible solvent (L) to obtain a gel (B), which is dried. The invention further relates to the porous materials which can be obtained in this way and the use of the porous materials as thermal insulation material, for cosmetic applications, for biomedical applications or for pharmaceutical applications.
Abstract:
Provided are porogen compositions and methods of using such porogen compositions in the manufacture of porous materials, for example, porous silicone elastomers. The porogens generally include comprising a core material and shell material different from the core material. The porogens can be used to form a scaffold for making a resulting porous elastomer when the scaffold is removed.
Abstract:
The present disclosure provides composites comprising an open cell foam and a small pore area material, methods for their preparation, articles of manufacture comprising them and methods for preparing the same.