hydrophilic poly(alkylene oxide) groups of the formula: Z-Q-(CH(R.sup.1)--CH.sub.2-Q).sub.n-R.sup.2, wherein Z is a polymerizable ethylenically unsaturated moiety, R.sup.1 is a H or a C.sub.1 to C.sub.4 alkyl group, R.sup.2 is a H, a C.sub.1 to C.sub.4