Iodine molecular weight regulators in suspension polymerization systems
AssigneePhillips Petroleum Company
InventorsGeorge A. Moczygemba, W. Delmar Johnson, Earl Clark
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Abstract
Iodine or organic iodides are effective in suspension polymerization systems as molecular weight regulators or modifiers. These modifiers are especially suited for the suspension ABS processes.
Claims16
In an aqueous suspension polymerization system, wherein at least one polymerizable monomer polymerizable under aqueous suspension polymerization conditions is polymerized under aqueous suspension polymerization conditions, including water, suspending agent, and in the presence of a molecular weight modifier, optionally with a free radical initiator, wherein said polymerizable monomer comprises a monovinyl-substituted aromatic compound, .alpha.,.beta.-unsaturated nitrile, ester of acrylic acid, ester of alkacrylic acid, or vinyl ester, the improvement which comprises the step of employing elemental iodine as said molecular weight modifier.
An aqueous suspension polymerization system wherein at least one polymerizable monomer selected from the group consisting of monovinyl-substituted aromatic compounds, alpha, beta-unsaturated nitriles, esters of acrylic acid, esters of alkacrylic acid, and vinyl esters, is polymerized under aqueous suspension polymerization conditions in the presence of a molecular weight modifier, the improvement which comprises employing elemental iodine as said molecular weight modifier.
An aqueous suspension polymerization process wherein at least one polymerizable monomer polymerizable under aqueous suspension polymerization conditions is polymerized under aqueous suspension polymerization conditions employing a free-radical generating initiator and a molecular weight modifier,
- wherein said at least one polymerizable monomer is an admixture of styrene:acrylonitrile,
- wherein the aqueous suspension polymerization admixture contains about 20 to 60 percent by weight of monomer based on total weight of the entire mixture including water,
- wherein said free radical generating initiator comprises t-butyl-peroctoate employed in an amount representing about 0.005 to 1 weight percent of the total weight of polymerizable monomer charged,
- wherein said aqueous suspension polymerization conditions include polymerization temperatures in the range of about 50.degree. C to 150.degree. C,
- and wherein said molecular weight modifier is elemental iodine employed in an amount equal to about 0.01 to 2 weight percent based on the weight of said polymerizable monomer charged to said aqueous suspension polymerization system.
An aqueous suspension polymerization process wherein at least one polymerizable monomer polymerizable under aqueous suspension polymerization conditions is polymerized under aqueous suspension polymerization conditions employing a free-radical generating initiator, a molecular weight modifier, and suspending agent,
- wherein said at least one polymerizable monomer is an admixture of a polymerizable monovinyl-substituted aromatic compound of 8 to 20 carbon atoms per molecule with an alpha, beta-unsaturated nitrile of up to 20 carbon atoms per molecule,
- wherein the final aqueous suspension polymerization admixture contains about 20 to 60 percent by weight of monomer based on total weight of the entire mixture including water,
- wherein said free radical generating initiator comprises a monomer-soluble organic peroxide, hydroperoxide, or azo compound employed in an amount representing about 0.005 to 1 weight percent of the total weight of polymerizable monomer charged,
- wherein said aqueous suspension polymerization conditions include polymerization temperatures in the range of about 50.degree. C to 150.degree. C,
- and wherein said molecular weight modifier is elemental iodine employed in an amount equal to about 0.01 to 2 weight percent based on the weight of polymerizable monomer charged to said aqueous suspension polymerization system.
Dependencies are inferred from the claim text.