Graft terpolymers bearing polyether side chains and poly(methacrylate) stems were synthesized by the graft-onto reaction of monoamino-terminated poly(PO9-co-EO1) to poly{[5-(methacryloyloxy)methyl-1,3-oxathiolane-2-thione]-co-n-butyl methacrylate} [poly(DTCMMA-co-BuMA)]. The grafting reaction proceeded via the nucleophilic addition of the terminal amino groups to the five-membered cyclic dithiocarbonate moieties giving thiol moieties, although the grafting efficiency was low (934%) due to the steric hindrance of the side chains. The Tg values of the poly{[DTCMMA-graft-poly(PO9-co-EO1)]-co-BuMA} ranged 2747 degrees C, depending on the amounts of flexible poly(PO9-co-EO1) chains introduced lowering the Tg values. Poly{[DTCMMA-graft-poly(PO9-co-EO1)]-co-BuMA}s bearing thiol groups were applied for the modification of wool via the disulfide exchange reaction. The modified wool had better dye ability toward a pigment from safflower than the original wool owing to the hydrophilic nature of poly{[DTCMMA-graft-poly(PO9-co-EO1)]-co-BuMA} introduced. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012