Crosslinked polymer gels for boron extraction derived from N-glucidol-N-methyl-2-hydroxypropyl methacrylate

Glycidyl methacrylate was reacted in 2-methyl pyrrolidone solution with N-methyl-D-glucamine (NMG) to produce N-D-glucidol, N-methyl-2-hydroxy propyl methacrylate (GMHP). The reaction proceeded exclusively via ring opening of the oxirane. The resulting vinyl monomer was a waxy product and soluble in water, ethanol, methanol, DMF, and NMP. Copolymerization of GMHP with N,N′-tetraallyl piperazinium dichloride by the inverse suspension method (water in oil), using a toluene/chloroform (3:1) mixture as continuous phase, led to crosslinked hydrogels in imperfect bead form. Crosslinking was also achieved without using additional crosslinker. Heating of N-methyl-D-glucamine with 10% excess of glycidyl methacrylate in NMP at 60°C for 4 h, resulting the formation of N-methyl-D-glucamine carrying two methacrylate groups. These dimethacrylate groups serve as a crosslinking agents. In situ redox polymerization of the mixture in water led to transparent hydrogels. These hydrogels in the swollen state have been demonstrated to be very efficient sorbents for the removal of boron on ppm levels. The boron loaded polymers can be regenerated by simple acid (0.1 M HCl) and base (0.1 M NaOH) treatment.