摘要:
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.
摘要:
Ethylenically unsaturated material susceptible to free radical polymerization, e.g., vinyl chloride monomer, is polymerized, e.g., in an aqueous medium, with an initiator system comprising, in combination, dialkyl pyrocarbonate, hydrogen peroxide, and alkaline reagent, e.g., sodium bicarbonate. The initiator system is added to the polymerization medium in amounts sufficient to polymerize the ethylenically unsaturated material.
摘要:
Di-(2-phenoxyethyl) peroxydicarbonate and improved processes employing same as initiators for the polymerization of ethylenically unsaturated monomers (such as vinyl chloride) and as curing catalysts for curing unsaturated polyester resin compositions.
摘要:
A method of polymerizing acrylonitrile polymers at elevated temperatures and superatmospheric pressure conditions in a novel organic, preferably aqueous-organic, reaction medium in which the monomeric reactants and the polymerized acrylonitrile are soluble under the polymerization conditions. The polymerization conditions may correspond to or are conveniently changed to polymer shaping conditions utilizing the same solvent-reaction medium, thus eliminating polymer recovery, polymer washing, polymer dissolution and the like, process steps. The organic polymerization medium is a monomer and polymer solvating amount of acetonitrile, generally in an amount of 60 to 100 percent by weight of the solvent solution with the residual amount being preferably water. The process is particularly suitable for continuous reaction and polymer shaping wherein an effluent solution of polymer and organic or aqueous-organic reaction medium is continuously withdrawn from the reaction system, maintained under solubilizing conditions of heat and superatmospheric pressure, with suitable adjustment of solvent concentrations as desired to provide homogeneous polymer suitable for extrusion into a shaped article.
摘要:
A catalyst, containing a ketone peroxide, e.g., methyl ethyl ketone peroxide, and an organic non-ketonic diperoxide, e.g., 2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxy)hexane, is used to cure polyester resins containing over 900 p.p.m. of an inhibitor. A small amount of sodium methoxide can be used as part of the catalyst. More specifically, polyester resins containing 900 to 40,000 p.p.m. of inhibitors can be cured within 10 minutes to 24 hours with the novel catalyst.