Porous materials based on aromatic amines

A porous material comprising, in reacted form:

• (a1) a polyfunctional isocyanate;
• and
• (a2) a polyfunctional substituted aromatic amine (a2-s) of formula (I):
• wherein:
• R1 and R2 are each hydrogen;
• and
• Q1 and Q1′ are each a primary amino group;
• Q3, Q3′, Q5, Q5′ are each hydrogen;
• and
• Q2, Q2′, Q4 and Q4′ are each independently a linear or branched alkyl group comprising from 1 to 12 carbon atoms, and
• wherein the component (a2) optionally comprises a further polyfunctional amine which is different from the amine (a2-s) of formula (I) and is selected from the group consisting of a polyfunctional aliphatic amine (a2-a) and polyfunctional aromatic amine (a2-u),
• wherein the polyfunctional aromatic amine (a2-u) is selected from the group consisting of isomers and derivatives of diaminodiphenylmethane and isomers and derivatives of toluenediamine,
• wherein the polyfunctional aliphatic amine (a2-a) is a polyalkylenepolyamine,
• wherein the porous material is in the form of a xerogel and has a volume-weighted average pore diameter of at least 1.4 μm and at most 4 μm,
• wherein the porous material comprises, in reacted form, from 35 to 65% by weight of the isocyanate component (a1) and from 35 to 65% by weight of the amine component (a2), where a sum of the % by weight of the components (a1) and (a2) is 100% by weight,
• wherein the porous material has a porosity of at least 85% by volume and a pore volume of 5.5 to 6.3 mL/g,
• wherein the porous material has a density of 100 to 200 g/L, and
• wherein the component (a1) is at least one polyfunctional isocyanate selected from the group consisting of diphenylmethane 4,4′-diisocyanate, diphenylmethane 2,4′-diisocyanate, diphenylmethane 2,2′-diisocyanate, and oligomeric diphenylmethane diisocyanate.