摘要:
Compositions and methods for inhibiting polymerization of vinyl aromatic monomers in oxygen-free processing systems are disclosed. The compositions comprise an oxime compound and a hydroxylamine compound and, alternatively, an oxime compound, a hydroxylamine compound and a phenylenediamine compound. The methods comprise adding either of the compositions to the vinyl aromatic monomer in an amount ranging from 1 to about 10,000 parts per million parts monomer.
摘要:
Disclosed are compositions and methods for inhibiting polymerization of ethylenically unsaturated monomers. The compositions comprise a methoxyphenol compound selected from the group consisting eugenol and 2-tert-butyl-4-hydroxyanisole and a phenylenediamine compound. The methods comprise adding from about 1 to about 10,000 parts per million to the ethylenically unsaturated monomer during processing.
摘要:
Synergistic composition and method of use are disclosed. The compositions comprise a quinone methide derivative and a hydroxylamine compound. These compositions demonstrate synergism at inhibiting the polymerization of a vinyl aromatic monomer. Preferably the quinone methide derivative is 2,6-di-tert-butyl-4-benzylidene-cyclo-2,5-dienone and the hydroxylamine compound is N,N-bis(hydroxypropyl)hydroxylamine.
摘要:
An alpha-tocopherol is disclosed as a polymerization inhibitor effective against vinyl monomer polymerization. Alpha-tocopherol was found to inhibit polymerization of acrylonitrile and diolefines such as isoprene and butadiene. Alpha-tocopherol was found to interact synergistically with hydroquinone in inhibiting polymerization of acrylonitrile.
摘要:
Methods and compositions for inhibiting fouling in vinyl monomers are disclosed. Alkylphosphonate esters or acids thereof are added to vinyl monomers, particularly ethylene dichloride, that are undergoing processing to inhibit fouling.
摘要:
Vinyl aromatic monomer polymerization methods utilizing a composition of 2,6-di-tert-butyl-4-methylphenol and a substituted benzoquinonediimide compound are disclosed. Preferably, the composition is employed in an amount of 1 part to 10,000 parts per million parts monomer during distillation of styrene.
摘要:
Methods and compositions for inhibiting the polymerization of crude dichlorobutene during its processing are disclosed. The methods comprise adding an effective polymerization inhibiting amount of a composition of a hydroxylamine compound and a metal deactivator compound to the dichlorobutene. The preferred hydroxylamine compound is bis-(2-hydroxypropyl)hydroxylamine and the preferred metal deactivator compound is a Mannich reaction product.
摘要:
An improved method for inhibiting the polymerization of vinyl aromatic monomer with a hydroxylamine compound is disclosed. The improvement provides for adding a catalytic amount of a phenylenediamine compound to the vinyl aromatic system while replacing any phenylenediamine compound lost as a result of physical removal from the system via the waste stream.