A process, which does not utilize a non-aqueous solvent, for producing a ultraviolet (UV) curable adhesive or sealant composition comprising a monohydroxylated epoxidized polydiene block polymer prepared from at least two polymerizable ethylenically unsaturated hydrocarbon monomers, wherein at least one block having a molecular weight from 100 to 15,000 is prepared from a diene monomer which provides unsaturation suitable for epoxidation, and wherein the polymer contains from 0.1 to 7.0 milliequivalents of epoxy per gram of polymer, and a tackifying resin, said process comprising mixing the epoxidized polymer and the tackifying resin with a photoinitiator which is insoluble in a mixture of the polymer and the tackifying resin under high shear conditions in a high shear mixer at a shear rate of at least 38,000 S.sup.-1 or in a sonicator at a power density of at least 4 watts per milliliter.