. " : ##STR2## wherein R is a substituted or unsubstituted monovalent hydrocarbon radical, E is an epoxy radical-containing organic group, B is selected from the group consisting of substituted monovalent hydrocarbon radicals, unsubstituted monovalent hydrocarbon radicals, and epoxy radical-containing organic groups, x has a value from 0 to 25, y has a value from 1 to 30, and the value of x+y ranges" . . .