A compound having the formula:((CH.sub.2 .dbd.CR.sup.1 --C(O)O--) .sub.x R.sup.2 --(O--C(O)R.sup.3).sub.y --O--C(O)).sub.n --R.sup.4 --(C(O)OM) .sub.mwherein:R.sup.1 is hydrogen or methyl,R.sup.2 is an alkylene group or substituted alkylene group (typically having less than six carbon atoms, more typically two or three carbon atoms),R.sup.3 is an alkylene group or substituted alkylene group (typically having less than ten carbon atoms, more typically from four to six carbon atoms),R.sup.4 is an aromatic radical (e.g. the residue of an aromatic polycarboxylic polyanhydride having a functionality of one half the sum of n and m),n and m are integers from two to four (typically two or three),x is an integer from one to three, andy is an integer from one to five.Among the compounds which fall within the above formula are those in which R.sup.1 is hydrogen, R.sup.2 is an ethylene group, R.sup.3 is a pentamethylene group, and R.sup.4 is the residue of benzene tetracarboxylic dianhydride or benzophenone tetracarboxylic dianhydride, n and m are each two, x is one, and y is two. This invention also relates to a polymerizable composition comprising a compound as set forth above and to a method of coating a substrate comprising polymerizing a composition comprised of the compound set forth above while in contact with a substrate.