A liquid binder composition for binding fibrous materials comprising: a) one or more multifunctional epoxy resins; b) a polyarylsulphone polymer; c) one or more surfactants selected from: (i) nonionic surfactant which is mono or multi-functional block or graft block copolymers comprising hydrophilic and hydrophobic blocks; (ii) anionic surfactant which is represented by the following formula: A-R wherein R is an alkyl, aryl, aryl-alkyl, or an alkylene chain having 4-50 carbon atoms (C 4 to C 50); and A is lithium, sodium, potassium, ammonium, quaternary ammonium amine salt of a carboxylic-, or sulfonic-, or phosphoric acid group; and (iii) a combination of nonionic surfactant and anionic surfactant; and d) water, wherein said composition is free of organic solvents, and wherein said polyarylsulphone polymer is soluble in the one or more epoxy resins upon curing thereof; and wherein said polyarylsulphone polymer is comprised of ether-linked repeating units and optionally thioether-linked repeating units, the units being selected from: -(Ph-A-Ph)- and optionally - (Ph) a - wherein A is CO or SO 2, Ph is phenylene, n = 1 to 2 and can be fractional, a = 1 to 4 and can be fractional, provided that when a exceeds 1, the phenylenes are linked linearly through a single chemical bond or a divalent group other than -CO- or -SO 2 -, or are fused together directly or via a cyclic moiety selected from the group consisting of an acid alkyl group, a (hetero) aromatic, a cyclic ketone, a cyclic amide, an imide, a cyclic imine and combinations thereof. a) one or more multifunctional epoxy resins; b) a polyarylsulphone polymer; c) one or more surfactants selected from: (i) nonionic surfactant which is mono or multi-functional block or graft block copolymers comprising hydrophilic and hydrophobic blocks; (ii) anionic surfactant which is represented by the following formula: A-R wherein R is an alkyl, aryl, aryl-alkyl, or an alkylene chain having 4-50 carbon atoms (C 4 to C 50); and A is lithium, sodium, potassium, ammonium, quaternary ammonium amine salt of a carboxylic-, or sulfonic-, or phosphoric acid group; and (iii) a combination of nonionic surfactant and anionic surfactant; and (i) nonionic surfactant which is mono or multi-functional block or graft block copolymers comprising hydrophilic and hydrophobic blocks; (ii) anionic surfactant which is represented by the following formula: A-R wherein R is an alkyl, aryl, aryl-alkyl, or an alkylene chain having 4-50 carbon atoms (C 4 to C 50); and A is lithium, sodium, potassium, ammonium, quaternary ammonium amine salt of a carboxylic-, or sulfonic-, or phosphoric acid group; and (iii) a combination of nonionic surfactant and anionic surfactant; and d) water, wherein said composition is free of organic solvents, and wherein said polyarylsulphone polymer is soluble in the one or more epoxy resins upon curing thereof; and wherein said polyarylsulphone polymer is comprised of ether-linked repeating units and optionally thioether-linked repeating units, the units being selected from: -(Ph-A-Ph)- and optionally - (Ph) a - wherein A is CO or SO 2, Ph is phenylene, n = 1 to 2 and can be fractional, a = 1 to 4 and can be fractional, provided that when a exceeds 1, the phenylenes are linked linearly through a single chemical bond or a divalent group other than -CO- or -SO 2 -, or are fused together directly or via a cyclic moiety selected from the group consisting of an acid alkyl group, a (hetero) aromatic, a cyclic ketone, a cyclic amide, an imide, a cyclic imine and combinations thereof.