9 carbon atoms; T is alkylene having 1 to 4 carbon atoms, wherein the alkylene may include straight-chain alkylene or branched alkylene or arylene having 6 to 9 carbon atoms; n is 0 or 1; S1 and S2 are, independently of one another, ???OCkH2k??? or ???OCH2CHR3???, wherein k is 2 or 3, R3 is an alkyl group having 1 to 9 carbon atoms, an aryl group having 6 to 9 carbon atoms; and 6???m 1 +m 2???25;