5:1 to 100:1, and m+n=15-100; d) a dispersant comprising at least one polymer or a salt thereof having the form of a copolymer of i) a maleic anhydride half-ester with a compound of the formula RO(AO)mH, wherein R is a C1-C20 alkyl group, A is a C2-4 alkylene group, and m is an integer from 2-16; and ii) a monomer having the formula CH2???CHCH2???(OA)nOR, wherein n is an integer from 1-90 and R i