Amino-modified poly(glycidyl methacrylate) based nanocomposites: textural properties and application

Abstract

Crosslinked macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) and copolymer nanocomposite with acid modified bentonite clay were prepared by radical suspension copolymerization and functionalized with diethylene triamine. Both samples were characterized by elemental and textural analysis (mercury intrusion porosimetry). The incorporation of the acid modified clay into the copolymer matrix lead to the increase of porosity, total pore volume and particularly specific surface area, while the process only slightly altered the acid–base properties. The obtained amino-functionalized nanocomposite was tested as 4-nitrophenol (4-NP) sorbent. The influence of pH, sorption time and initial 4-nitrophenol (4-NP) concentration on sorption efficiency of synthesized samples was studied. Since the pHPZC of the functionalized copolymer and the functionalized composite was the same, and the amount of amino groups was slightly higher for the copolymer, the enhanced sorption properties can be ascribed to improved textural properties of composite, particularly the increased specific surface area. The isotherm data were best fitted with Langmuir model, while the sorption dynamics obeyed the pseudo-second-order kinetic model. The results in this study show great potential for designing functionalized macroporous glycidyl methacrylate copolymers and their acid modified bentonite composites as promising sorbents in 4- nitrophenol removal from wastewaters.