of a diisocyanate molecule for example 2 4 toluylene 2 6 toluylene tetramethylene hexamethylene trimethylhexamethylene isophorone and the like r 4 is bivalent linear or branched alkyl aryl polyester or polyether each optionally substituted with one or more non interfering substituents and the like r 5 could be hydrogen or a monovalent linear or branched aliphatic olefinic by which is included any degree of unsaturation or aromatic hydrocarbon radical of up to 50 carbon atoms preferably up to 20 carbon atoms optionally substituted with one or more non interfering substituents often at least a portion of the functional groups u0192 are epoxy groups and or acrylate or methacrylate groups strength of the present invention is that the functional groups can be varied to a great extent creating various types of oligomers with various properties in addition to varying r 3 via the selection of a different functional group or different r 4 group the polymer formation from the oligomer may be varied by regulating the proportion of the r 3 groups that are simply isocyanate an examplary pruo having a poly oxypropylene triol backbone and methacrylic and epoxy fgs has the following formula the following are some advantageous reasons to use combinations of various functional groups in one oligomeric molecule 1 in the case of a pruo containing primarily acrylic groups and up to.