| 摘要 |
PURPOSE:To obtain a high-MW polymer within a short time without the need of removing aldehydes contained as an impurity in the material, by polymerizing an acrylic acid monomer containing aldehydes by using a specified redox catalyst system. CONSTITUTION:Polymerization of a (meth)acrylic acid monomer containing aldehydes as an impurity or a mixture of said monomer with monomers copolymerizable therewith in an aqueous solution is performed by adding to the system a water-soluble peroxide [e.g., H2O2 or (NH4)2S2O8] and a thiosulfate [e.g., (NH4)2S2O3 or Na2S2O3] at a molar ratio of 1:2-10. A high-MW polymer can be obtained within a short time though the material is used in polymerization without removing the aldehydes contained in it. When a water-soluble polymer is desired, a water-soluble one of good water solubility can be obtained, and when this polymer is converted into one having a crosslinked structure, an excellent high-molecular water absorbent can be obtained in good yields.
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