Provided is a composition comprising one or more compound having the structure of formula II: wherein A is a residue of a polyisocyanate, L is a linking group formed by a reaction of an isocyanate group with an isocyanate-reactive group, n is 5 to 25, m is 0 to 100, and Z is methyl or ethyl or propyl, and wherein the ratio of the sum of the moles of isocyanate groups plus the moles of said L groups to the moles of said Z groups is 2:1 to 30:1. Also provided is an emulsion in which the particles comprise such a composition and further comprise one or more water-insoluble compound that does not have the structure A-NCO.