主权项 |
1. A process for producing a xerogel composite, comprising:
(a) preparing an organic gel precursor (A) comprising a polyfunctional isocyanate monomer component (A1) and a polyfunctional aliphatic amine monomer component (A2); (b) reacting the polyfunctional isocyanate monomer component (A1) and the polyfunctional aliphatic amine monomer component (A2) in the presence of an open-celled macroporous foam (B) and a solvent (C) to obtain a xerogel composite; and (c) drying the xerogel composite by conversion of the solvent (C) into the gaseous state at a temperature and a pressure below the critical temperature and the critical pressure of the solvent (C), wherein a porosity of the xerogel is at least 70% by volume, the xerogel composite is not brought into contact with an organic fluid after (b), and the polyfunctional aliphatic amine is at least one selected from the group consisting of bis(2-aminoethyl)amine, tris(2-aminoethyl)amine, triethylenetetramine, tetramethylenediamine, ethylenediamine, a diamine of butane, a diamine of pentane, 2-methyl-1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,12-diaminododecane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 4,4′-methylenebis(cyclohexylamine), 4,4′-diaminodicyclohexyl-1,2-propanediamine, 4,4′-diaminodicyclohexyl-1,3-propanediamine, 2,4′-diaminodicyclohexyl-1,2-propanediamine, 2,4′-diaminodicyclohexyl-1,3-propanediamine, 2,2′-diaminodicyclohexyl-1,2-propanediamine, 2,2′-diaminodicyclohexyl-1,3-propanediamine, 2-methyl-1,2-diaminopropane, 2,2-dimethyl-1,3-diaminopropane, bis(4-amino-3-methylcyclohexyl)methane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, bis(1,3-methylamino)cyclohexane, a bishydrazide, a bissemicarbazide, N,N,N-tris(2-aminoethyl)amine, guanidine, N-(2-aminoethyl)-1,3-diaminopropane, tetraethylenepentamine, pentaethylenehexamine, diaminopropyleneethylenediamine, propylenediamine, hexamethylenediamine, diaminocyclohexane, triglycol diamine, 1,3-diaminopropan-2-ol, ω,ω′-diaminodi-n-hexylamine, dimethyl 1,4-diaminoadipate and a polyalkylenepolyamine. |