Photoinduced Cografting of Vinyl Benzyl Trimethylammonium Chloride and 2-Hydroxyethyl Methacrylate onto Nylon Nonwoven Fabric for Preparing an Anion-Exchange Sorbent: Optimum Cografting Conditions and Characterization

摘要

Vinyl benzyl trimethylammonium chloride (VBTAC) and 2-hydroxyethyl methacrylate (HEMA) were cografted onto nylon fiber by photoirradiation-induced graft polymerization with benzophenone (BP) as the photoinitiator and methanol (MeOH) as the solvent. The cografted VBTAC afforded an anion-exchange functionality to the nylon-g-HEMA VBTAC fabric without any further modification. The concentration of each and the ratio of the HEMA and VBTAC monomers in solution were the most important factors determining the degree of grafting and anion-exchange capacity (AEC) of nylon-g-HEMA VBTAC. With regard to the AEC of the grafted fabric, the optimal HEMA/VBTAC ratio was 10 : 7 (v/w), which gave a molar fraction of VBTAC of 0.286. The photoirradiation time, temperature of the reaction, and concentrations of BP and MeOH were optimized for the cografting of VBTAC and HEMA onto the nylon fabric. The molar ratio of VBTAC units in the grafted polymer was dependent on the photoirradiation time but not on the other parameters. The results showed that the AEC of nylon-g-HEMA VBTAC was governed directly by its VBTAC density rather than by its degree of grafting. The grafted fabric was characterized in terms of its surface area, porosity, and surface charge density by Fourier transform infrared, C-13-NMR, and scanning electron microscopy studies, and the regeneration efficiency was estimated.