Photoinduced grafting of vinyl benzyl trimethyl ammonium chloride on polyester nonwoven fabric with surfactant coating and its anion-exchange properties

Abstract

Vinyl benzyl trimethyl ammonium chloride (VBTAC) could be efficiently and stably grafted onto polyester fiber coated with a surfactant polyester (PET) by a photoirradiation-induced graft polymerization with benzophenone as the photoinitiator without any cografting monomer required. The degree of VBTAC grafting could be controlled simply by the irradiation time and concentration of VBTAC in the monomer solution. The anion-exchange capacity (AEC) of the PET-g-VBTAC fabrics increased with increasing degree of grafting up to 80±5% and then leveled off. The maximum AEC of PET-g-VBTAC was 2.2 mequiv/g; this was similar to that of a commercial anion-exchange resin (2.16±0.04 mequiv/g) and much higher than those of nylon-g-VBTAC-2-hydroxyethyl methacrylate fabrics (≤1.0 mequiv/g) prepared with a conventional cografting system. The grafted fabric was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy studies, and the sorption selectivity for anions and regeneration efficiency were estimated. The results suggest that the grafting system, in which VBTAC alone was grafted onto PET fiber coated with surfactant, was more practical and effective for the preparation of the VBTAC-containing anion exchanger, and the resulting PET-g-VBTAC fabrics could be used as an effective anion exchanger.