Claims
- 1. 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.
- 2. 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.
- 3. The process according to claim 2 wherein is employed 0.01 to 2 weight percent of said elemental iodine relative to the total weight of polymerizable monomer charged to the aqueous suspension polymerization system.
- 4. The process according to claim 3 wherein said aqueous suspension polymerization system employs said free radical initiator, wherein said free radical initiator is a peroxide, hydroperoxide, or azo compound, employed in a range of about 0.005 to 1 weight percent relative to the total weight of polymerizable monomer charged to the aqueous suspension polymerization system.
- 5. The process according to claim 4 wherein said at least one polymerizable monomer is selected from the group consisting of styrene, ethyl styrene, acrylonitrile, methacrylonitrile, methylacrylate, vinyl acetate, vinyl butyrate, 4-vinylbiphenyl, and 2-vinylnaphthalene.
- 6. The process according to claim 5 wherein said polymerizable monomer is a mixture of polymerizable monomers selected from the group consisting of butadiene/styrene, styrene/acrylonitrile, and butadiene/styrene/acrylonitrile.
- 7. The process according to claim 6, wherein said aqueous suspension polymerization system employs styrene/acrylonitrile as said polymerizable monomers, and said free radical initiator is t-butylperoctoate.
- 8. The process according to claim 4 wherein said aqueous suspension polymerization system further employs a hydrocarbon diluent.
- 9. The process according to claim 4 wherein said aqueous suspension polymerization system initially contains about 20 to 60 weight percent of polymerizable monomer based on total weight of entire mixture.
- 10. The process according to claim 9 wherein said elemental iodine is employed in a range of about 0.4 to 1.5 weight percent based on the weight of polymerizable monomer charged to the system.
- 11. The process according to claim 4 wherein said free radical initiator is di-t-butyl peroxide, t-butyl peroctoate, benzoyl peroxide, lauroyl peroxide, toluyl peroxide, t-butyl peracetate, t-butyl perbenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, t-butyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, cyclopentane hydroperoxide, diisopropylbenzene hydroperoxide, pinene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide,2,2'-azobis(2-methylpropionitrile), or 2,2'-azobis(2-methylvaleronitrile).
- 12. 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.
- 13. The process of claim 12 wherein said admixture represents about a 70:30 weight ratio styrene:acrylonitrile.
- 14. 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.
- 15. The process according to claim 6 wherein said aqueous suspension polymerization system employs styrene/acrylonitrile as said polymerizable monomers, and said free radical initiator is benzoyl peroxide.
- 16. The process according to claim 14 employing styrene and acrylonitrile as said polymerizable monomers in a weight ratio of about 70:30 styrene:acrylonitrile, and said free radical generating initiator is t-butyl peroctoate or benzoyl peroxide.
Parent Case Info
This is a divisional application of Ser. No. 510,040, filed Sept. 27, 1974, now U.S. Pat. No. 3,983,187, patented Sept. 28, 1976, which was a continuation application of Ser. No. 303,330 filed Nov. 3, 1972, now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
2647107 |
Barnes |
Jul 1953 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
510040 |
Sep 1974 |
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Continuations (1)
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Number |
Date |
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Parent |
303330 |
Nov 1972 |
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