Novel functionalized peroxides which may be used as crosslinking, grafting and curing agents, initiators for polymerization reactions and as monomers for condensation polymerizations to form peroxy-containing polymers, which in turn can be used to prepare block and graft copolymers, have the following Formula I: ##STR1## R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, X, Y.sup.1, Y.sup.2, Y.sup.3, Z.sup.1, Z.sup.2, x, y and z are as defined in the Summary of the Invention. The compounds of Formula I may be prepared by reacting hydroxy-containing tertiary hydroperoxides with diacid halides, phosgene, dichloroformates, diisocyanates, anhydrides and lactones to form the functionalized peroxides. These reaction products may be further reacted, if desired, with dialcohols, diamines, aminoalcohols, epoxides, epoxy alcohols, epoxy amines, diacid halides, dichloroformates and diisocyanates to form additional functionalized peroxides.