Abstract: A storage stable aqueous dispersion useful in the curing and foaming of unsaturated polyester resins containing an aromatic diacyl peroxide, an alkali metal carbonate or bicarbonate and dispersion-stabilizing amounts of magnesium aluminum silicate and an alkali metal carboxymethyl cellulose. Also disclosed is the preparation of foamed polyester resins using the dispersion.

Abstract: Novel processes and compositions are provided for the preparation of foamed, cross-linked polyethylene utilizing di(alkylperoxy)acetylene cross-linking/blowing agents. The novel compositions include esters of thiodipropionic acid as activators.

Abstract: Gem-diperoxyesters of the formula: ##STR1## where R is selected from methyl and ethyl; R.sub.1 is ethyl when R is ethyl; R.sub.1 is hydroxyalkyl of 1 to 7 carbon atoms when R is methyl; and each R.sub.2 is ##STR2## where each of R.sub.3, R.sub.4, and R.sub.5 is selected from hydrogen and alkyl, provided not more than one of R.sub.3, R.sub.4, and R.sub.5 is hydrogen, R.sub.3, R.sub.4, and R.sub.5 collectively containing from 2 to 12 carbon atoms.The compounds are particularly efficient at varying temperatures from ambient to 60.degree. C. for the initiation of the polymerization of vinyl chloride. They also have high efficiency in the curing of polyester resins and in the polymerization of other monomers and comonomers having ethylenic unsaturation.

Abstract: Gem-diperoxyesters of the formula: ##STR1## where R is selected from methyl and ethyl; R.sub.1 is ethyl when R is ethyl; R.sub.1 is hydroxyalkyl of 1 to 7 carbon atoms when R is methyl; and each R.sub.2 is ##STR2## where each of R.sub.3, R.sub.4, and R.sub.5 is selected from hydrogen and alkyl, provided not more than one of R.sub.3, R.sub.4, and R.sub.5 is hydrogen, R.sub.3, R.sub.4, and R.sub.5 collectively containing from 2 to 12 carbon atoms.The compounds are particularly efficient at varying temperatures from ambient to 60.degree. C. for the initiation of the polymerization of vinyl chloride. They also have high efficiency in the curing of polyester resins and in the polymerization of other monomers and comonomers having ethylenic unsaturation.

Abstract: A silicon peroxide selected from the formulas:(R').sub.4-n --Si--(OOR).sub.n (a) ##STR1## wherein n is an integer of 1-3; R is a t-octyl group in which a tertiary carbon atom is directly bonded to the peroxy group; and R' is selected from alkyl, phenyl, and alkenyl (provided n is not more than 2), and a carbon chain which forms a saturated heterocyclic ring with the silicon atom, each R' group having up to about 10 carbon atoms. Typical is trimethyl (2,4,4-trimethyl-2-pentylperoxy) silane. These molecules are useful as catalysts for curing polyester resins and are particularly advantageous as crosslinking agents for high density polyethylene in that crosslinking is effected at lower temperatures than required by the prior art.

Abstract: Cyclic and acyclic phenylene substituted dialkyl peroxides most of which are in an acyclic polymeric form.

Abstract: A silicon peroxide selected from the formulas:(R').sub.4-n --Si--(OOR).sub.n (a) ##STR1## wherein n is an integer of 1-3; R is a t-octyl group in which a tertiary carbon atom is directly bonded to the peroxy group; and R' is selected from alkyl, phenyl, and alkenyl (provided n is not more than 2), and a carbon chain which forms a saturated heterocyclic ring with the silicon atom, each R' group having up to about 10 carbon atoms. Typical is trimethyl (2,4,4-trimethyl-2-pentylperoxy) silane. These molecules are useful as catalysts for curing polyester resins and are particularly advantageous as crosslinking agents for high density polyethylene in that crosslinking is effected at lower temperatures than required by the prior art.

Abstract: Novel cyclic silylperoxides in which a silicon atom directly bonded to at least two peroxy oxygen atoms in a ring of from 8 to 11 atoms are useful as agents for crosslinking high density polyethylene and/or as catalysts for curing unsaturated polyester resins.

Abstract: Cyclic and acyclic phenylene substituted dialkyl peroxides most of which are in an acyclic polymeric form.