Abstract: A polyperoxyketal having at least one carboxy group--an acid, hydrocarbon ester, a metal ion, or as part of an anhydride. Illustrations are: n-Butyl .gamma.,.gamma.-bis-(t-butylperoxy) valerate and Barium .gamma.,.gamma.-bis(t-butylperoxy) valerate. These polyperoxyketals are vulcanizing agents for thermoplastic polymers such as rubber and ethylenepropylene rubber.

Abstract: A polyperoxyketal compound is provided having at least one carboxy group, a hydrocarbon ester. An example of this compound is n-butyl gamma,gamma-bis(t-butylperoxy)valerate. This polyperoxyketal compound is used as a vulcanizing agent for thermoplastic polymers such as rubber and ethylene-propylene rubber.

Abstract: Polymers of the formula [(A.sub.n.sbsb.1 -R-D.sub.n.sbsb.2).sub.v P.sub.n.sbsb.3 ].sub.w Z.sub.n.sbsb.4 where A is a peroxy-containing group; R is a 2-4 valent aliphatic, cycloaliphatic or aromatic radical; P is a polyvalent polymeric residue; D is a carbonyl-containing connecting group; and Z is a terminal group, such polymers being useful with vinyl monomers in the formation of block and graft polymers.

Abstract: A new class of compounds: R-W-R' where R and R' are identical oxy radicals containing peroxide functions such as dialkyl or diaralkyl peroxide, peroxyketal, peroxyester, or monoperoxycarbonate, and W is a carbonyl group, or carbonyl containing group, or an alkylidene or aralkylidene group, or a phosphorus containing group.Examples:Di[1,3-dimethyl-3-(t-butylperoxy)butyl] carbonate;Di[1,3-dimethyl-3-(n-butoxycarbonylperoxy)butyl] carbonate;2,2-Bis[3,3-di(t-butylperoxy)butoxy] propane;Di[1,3-dimethyl-3-(t-butylperoxy)butyl] ethyl phosphate.They are free radical affording compounds useful in crosslinking of polyolefins and unsaturated polymers, and for the polymerization of vinyl monomers and diolefinic monomers.