FIELD: chemistry.
SUBSTANCE: described is a sulphonated block-copolymer which is solid in water and contains at least two polymer terminal blocks A and at least one polymer inner block B, where: a) each block A is a polymer block which is resistant to sulphonation, and each block B is a polymer block which is susceptible to sulphonation, wherein said blocks A and B do not contain significant levels of olefinic unsaturation; b) each block A independently has number-average molecular weight between 1000 and 60000, and each block B independently has number-average molecular weight between 10000 and 300000; c) said blocks B are sulphonated in the range of 10-100 mol %; and d) where the said block-copolymer is insoluble in water and is moulded into an article having ultimate tensile stress greater than 100 pounds per square inch (689.5 kPa) in the presence of water according to ASTM D412; d) each block A is a polymer selected from polymerised para-substituted styrene or 1,3-butadiene monomers, having vinyl content less than 35 mol % before hydrogenation, each block B is a polymerised unsubstituted styrene, 1,1-diphenylethylene, a copolymer of unsubstituted styrene and 1,3-butadiene, a copolymer of unsubstituted styrene and alpha-methylstyrene, where any segments in blocks A and B, which contain polymerised 1,3-butadiene, are then hydrogenated, and where any block A, which contains polymerised hydrogenated polymers of conjugated acyclic diene, has melting point higher than 50°C. Described is a method of producing said sulphonated block-copolymer. The invention also describes a membrane formed at least partially from said sulphonated block-copolymer.
EFFECT: obtaining a polymer with good water transportation properties and sufficient strength in wet state.
30 cl, 4 dwg, 8 tbl, 16 ex
