摘要:
The present invention relates to a process for producing a foamed material, wherein a composition in the form of emulsion with a matrix-forming component, a surfactant component and a near-critical or supercritical blowing agent component is submitted to a lowering of pressure. The blowing agent component further comprises a hydrophobic co-component, which is soluble in supercritical CO2 at a pressure of ≧150 bar, is insoluble in subcritical CO2 at a pressure of ≦40 bar and is insoluble in the matrix-forming component and furthermore is present in a proportion from ≧3 wt % to ≦35 wt % of the blowing agent component. It further relates to a composition in the form of emulsion to be used herein and a foamed material obtainable by the process according to the invention.
摘要:
The present invention relates to a process for producing a foamed material, wherein a composition in the form of emulsion with a matrix-forming component, a surfactant component and a near-critical or supercritical blowing agent component is submitted to a lowering of pressure. The blowing agent component further comprises a hydrophobic co-component, which is soluble in supercritical CO2 at a pressure of ≧150 bar, is insoluble in subcritical CO2 at a pressure of ≦40 bar and is insoluble in the matrix-forming component and furthermore is present in a proportion from ≧3 wt % to ≦35 wt % of the blowing agent component. It further relates to a composition in the form of emulsion to be used herein and a foamed material obtainable by the process according to the invention.
摘要:
A process for producing a polyurethane foam with bimodal cell size distribution, comprising the following steps: providing a mixture in a mixing head, where the mixture comprises: A) a component reactive towards isocyanates; B) a surfactant component; C) a blowing agent component selected from the group consisting of linear, branched or cyclic C1- to C6-alkanes, linear, branched or cyclic C1- to C6-fluoroalkanes, N2, O2, argon and/or CO2, where blowing agent component C) is present in the supercritical or near-critical state; D) a polyisocyanate component; discharging the mixture comprising components A), B), C), and D) from the mixing head where, during the discharge of the mixture, the pressure prevailing in the mixture is lowered to atmospheric pressure.
摘要:
Process for producing a polyurethane foam and polyurethane foam obtainable therefrom A process for producing a polyurethane foam with bimodal cell size distribution, comprising the following steps: providing a mixture in a mixing head, where the mixture comprises: A) a component reactive towards isocyanates; B) a surfactant component; C) a blowing agent component selected from the group consisting of linear, branched or cyclic C1- to C6-alkanes, linear, branched or cyclic C1- to C6-fluoroalkanes, N2, O2, argon and/or CO2, where blowing agent component C) is present in the supercritical or near-critical state; D) a polyisocyanate component; discharging the mixture comprising components A), B), C), and D) from the mixing head where, during the discharge of the mixture, the pressure prevailing in the mixture is lowered to atmospheric pressure.
摘要:
The present invention relates to a process for producing a polyurethane foam, where the blowing agent used is present in the supercritical or near-critical state. A reaction mixture is introduced into a closed mould, where the closed mould has been set up in such a way that its interior volume and/or the pressure prevailing in its interior can be altered after the introduction of the mixture by external influence. Through the selection of the surfactant it is possible to obtain microemulsions of the blowing agent in the polyol phase. The invention further relates to a nanocellular polyurethane foam obtainable by the process of the invention.
摘要:
The present invention relates to a process for producing a polyurethane foam, where the blowing agent used is present in the supercritical or near-critical state. A reaction mixture is introduced into a closed mould, where the closed mould has been set up in such a way that its interior volume and/or the pressure prevailing in its interior can be altered after the introduction of the mixture by external influence. Through the selection of the surfactant it is possible to obtain microemulsions of the blowing agent in the polyol phase. The invention further relates to a nanocellular polyurethane foam obtainable by the process of the invention.
摘要:
The present invention relates to a reaction mixture in emulsion form, suitable for conversion into polyurethanes, comprising a first phase and a second phase in the emulsion and further comprising the following components: A) polyols; B) blowing agent; C) surfactants; and D) isocyanates, wherein the isocyanate-reactive compounds A) are present in the first phase of the emulsion and the blowing agent B) is present in the second phase. The blowing agent B) is present in the near-critical or supercritical state and the isocyanate D) is present in the second phase in a proportion of ≧10% by weight of the total amount of isocyanate D) in the composition. The invention further relates to a method of producing polyurethane foams by providing such a reaction mixture, wherein a polymerization takes place at the freshly formed interface between the polyol phase and the blowing agent phase, to the use of such a reaction mixture for producing polyurethane foams and also to the polyurethane foams obtained.
摘要:
The invention relates to bicontinuous microemulsions and to the use thereof as a fuel, combustion or heating fluid. Said fuels permit an increased efficiency of internal combustion systems and heating installations of any type and, simultaneously, a minimized emission of pollutants, associated with combustion, to be obtained.
摘要:
A method for producing rigid sugar micro-/nanofoams includes providing a solution with at least one sugar, a super- or near-critical fluid and a surfactant component as a (micro)emulsion. The (micro)emulsion is expanded so as to convert the super- or near-critical fluid from a state of liquid-like density to a state of gaseous density so as to thereby obtain a micro-/nanofoam. The micro-/nanofoam is then rigidified so as to obtain a rigid sugar micro-/nanofoam.
摘要:
The invention relates to bicontinuous microemulsions and to the use thereof as a fuel, combustion or heating fluid. Said fuels permit an increased efficiency of internal combustion systems and heating installations of any type and, simultaneously, a minimized emission of pollutants, associated with combustion, to be obtained.