Preparation method for ion exchange resin beads by stepwise suspension polymerization

Abstract

The invention discloses a method for preparing polymer beads for ion exchange resin through step-by-step suspension and polymerization. The method comprises the following steps: pre-polymerizing a monomer by taking a non-polar or polar monomer as a raw material and by adopting a compound dispersant and compound initiator system, performing a suspension polymerization process to prepare gel type polymer beads of an ion exchange resin precursor, or adding a polar or non-polar pore-forming agent in the monomer of the process to prepare macroporous polymer beads for the ion exchange resin precursor. The qualification rate of the beads prepared by the method in the grain size range of 0.3 to 0.8 mm can reach to 92 to 94 percent, the yield of the beads with the grain size of 0.02 to 0.04 mm canreach to 81 to 90 percent, and the uniformity of the while ball grain size can be obviously improved; furthermore, salt is not added in the preparation process, so the revenue can be increased, the cost can be reduced and the economic benefit is very considerable.

Description

technical field [0001] The invention belongs to the technical field of preparation of polymer beads of ion-exchange resin precursors, and in particular relates to a method for preparing ion-exchange resin beads by step-by-step suspension polymerization. Background technique [0002] Since the 1940s, the suspension polymerization process has gradually become one of the most important methods for the synthesis of various polymers, and has been industrialized on a large scale worldwide for more than half a century. Up to now, it is still one of the important synthetic methods of polymers such as polystyrene, polyvinyl chloride and polyacrylates. Among them, especially as polymer bead precursors (commonly known as white balls in the industry) for synthesizing various types of ion exchange resins and macroporous adsorption resins, they are produced by suspension polymerization process almost without exception at home and abroad. [0003] The suspension polymerization process mai...

AI Technical Summary

Problems solved by technology

[0005] First, the uniformity of white ball particle size is poor

According to the national standard, the yield of qualified white balls in the range of 0.3-0.8mm particle size can only reach 85-90% (calculated by monomer weight); secondly, for monomers with high polarity or water solubility, such as methyl methacrylate, etc. , or when it is necessary to add polar organic pore-forming solvents such as various alcohols to prepare macroporous white balls, 8-15% of inorganic salts such as table salt must be added to the dispersion medium water, otherwise the dissolution loss of monomers will increase greatly and it will be difficult to form balls , which will not only bring waste of resources, increased cost and increased pollution of mother liquor (Qian Tingbao. Ion Exchanger Application Technology [M]. Tianjin: Tianjin Science and Technology Press, 1984: 20-35)