Free-radical copolymerization of cyclohexyl methacrylate (CHMA) and tetra (ethylene glycol) dimethacrylate (TtEGDMA) were carried out at 60 °C in tetrahydrofuran solution in presence of 2,2-azobisisobutyronitrile. The random copolymers were prepared with nominal crosslinking ratios, X of 1, 5 and 10% mol TtEGDMA / mol CHMA. The copolymers were characterized by 13C NMR spectroscopy. The copolymers was characterized by 13C RMN analysis and determined the copolymers composition. The monomer reactivity ratios r1 (TtEGDMA) and r2 (CHMA) were determined with the linearized copolymerization equations of the Fineman–Ross methods (r1 = 1.77 and r2 = 0.48) and Kelen–Tüdös (r1 = 1.81 and r2 = 0.46). Parameters of Alfrey-Price Q1 = - 1.10 (specific activity) and e1= - 0.64 (polarity) for TtEGDMA.

Besides others, textile industries are the primary sources of discharging a massive amount of highly colored wastewater. Adsorption can be considered the most economically favorable technology method for removing dyes from wastewater. This paper reports the synthesis of Poly tetra (ethyleneglycol) dimethacrylate crosslinked with 2-hydroxypropyl methacrylate (Poly (TtEGDMA-cross-2-HPMA)) hydrogelsand its application as a novel sorbent to remove bemacid red (ET2) dye from aqueous solution under various operating conditions. The equilibrium adsorption capacity was found 142.82–883.60 mg ET2 g–1 of 1% TtEGDMA. The adsorbent was characterized using Fourier transform infrared radiation (FTIR) and 13carbon solid-state nuclear magnetic resonance spectra (13C-NMR). The effects of the experimental parameters include dye concentration and crosslinked agent concentration. The kinetic sorption uptake for ET2 by Poly (TtEGDMA-cross-2-HPMA) at various initial dye concentrations was analyzed by pseudo-first and pseudo-second models. Two sorption isotherms, namely the Langmuir and Freundlich isotherms, were applied to the sorption equilibrium data. The sorption kinetics of ET2 onto the hydrogels followed the pseudo-second-order kinetics model (R2 = 0.999) and the adsorption equilibrium data obeyed the Langmuir isotherm model (R2 = 0.999). It can be concluded that Poly (TtEGDMA-cross-2-HPMA) is an alternative economic sorbent to more costly adsorbents used for dye removal in wastewater treatment processes.