Development of a Simplified Radiation-Induced Emulsion Graft Polymerization Method and Its Application to the Fabrication of a Heavy Metal Adsorbent

A simplified radiation-induced emulsion graft polymerization (SREG) method is proposed. This method involves a convenient and easy degassing process of a monomer solution using a commercially available sealed glass jar. A loaded weight on the lid of the jar was used to control the jar’s internal pressure as the degassing of the monomer solution took place using a vacuum pump. The degassing method was highly reproducible, resulting from no bumping of the monomer solution. The initial grafting velocity was proportional to the absorbed doses of pre-irradiation between 5 and 20 kGy. This result indicates that dissolved oxygen was sufficiently eliminated from the monomer solution at such a level where the remaining oxygen had little effect on the grafting reaction at a dose of 5 kGy. The method was then applied to the fabrication of a heavy metal adsorbent that possessed a sufficient adsorption capacity of Co(II) ions. The SREG method is applicable to the fabrication of a wide variety of functional graft polymers because high-dose-rate gamma-ray radiation and expensive experimental equipment are not necessary.