Abstract:
High density polyethylene is cross-linked with certain cyclic perketals including a group of novel cyclic perketals. Typical of the novel molecules is 3,6,6,9,9-pentamethyl-3-ethylacetate-1,2,4,5-tetraoxy cyclononane.
Abstract:
A novel method of making foamed, crosslinked low density polyethylene utilizing as dual crosslinking/blowing agents, organic peroxides of the formula: ##STR1## where each R is a t-alkyl group bonded through its tertiary carbon atom and having 4-8 carbon atoms; and R' is an alkyl group of 1-6 carbon atoms.
Abstract:
Dialkyl diacyl peroxides in which the alpha carbon atom of one of the alkyl groups is secondary and substituted by chloro and alkyl. The compounds are useful as polymerization initiators of ethylenically unsaturated monomers such as vinyl chloride.
Abstract:
High density polyethylene is cross-linked with certain cyclic perketals including a group of novel cyclic perketals. Typical of the novel molecules is 3,6,6,9,9-pentamethyl-3-ethylacetate-1,2,4,5-tetraoxy cyclononane.
Abstract:
Acyl peroxycarbonic esters of the formula ##STR1## in which R is methyl or ethyl, R' is alkyl, and R and R' together have 17 or more carbon atoms. The compounds have unusual thermal stability, together with improved polymerization initiating efficiency. Particularly outstanding efficiency is found in connection with the curing of polyester resins.
Abstract:
Novel tertiary alkyl peresters of tertiary hydroperoxides are used as polymerization initiators wherein the peresters are characterized by the tertiary alkyl group of the acid moiety having at least two alkyl groups of two or more carbon atoms and the tertiary alkyl group of the hydroperoxide has at least five carbon atoms. Typical is the polymerization of certain vinyl monomers such as vinyl chloride.
Abstract:
Acyl peroxycarbonic esters of the formula ##STR1## in which R is methyl or ethyl, R' is alkyl, and R and R' together have 17 or more carbon atoms. The compounds have unusual thermal stability, together with improved polymerization initiating efficiency. Particularly outstanding efficiency is found in connection with the polymerization of methyl methacrylate.
Abstract:
Aliphatic peroxyester polymerization initiators whose thermal stability is controlled by a bromine or chlorine substituent on the carbon atom in the alpha position relative to the carbonyl group in the acid moity of the perester. The initiators show increased efficiency for the polymerization of methyl methacrylate, styrene, ethylene, and in curing unsaturated polyester resins. Typical is 1,1,3,3-tetramethyl butyl peroxy 2-chlorolaurate.
Abstract:
A crosslinking system which includes a 1,2,4-trioxacycloheptane and a crosslink-promoting polyfunctional ethylenically unsaturated compound. This system is employed in a process of crosslinking a thermoplastic polymer. Preferred polymers, useful in this process, include ethylene homopolymers and copolymers.
Abstract:
Dialkyl diacyl peroxides in which the alpha carbon atom of one of the alkyl groups is secondary and substituted by chloro and alkyl. The compounds are useful as polymerization initiators of ethylenically unsaturated monomers such as vinyl chloride.