Methacrylic acid functionalized CPS microspheres to adsorb shikimic acid

Abstract

Chloromethylated cross-linked polystyrene (CMCPS) microsphere is hydroxylated, obtaining hydroxylated cross-linked polystyrene microsphere (CPS-OH). Methacrylic acid (MAA) is grafted on the surface of CPS-OH microspheres by cerium salt-hydroxyl group redox initiation system, obtaining graft-polymerization functional microsphere CPS-g-PMAA. The chemical structure and physicochemistry characters of CPS-g-PMAA are characterized with infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The adsorption performance of the grafted microspheres CPS-g-PMAA for shikimic acid was mainly investigated and the adsorption mechanism was explored. The experiment results show that for the graft-polymerization of MAA, the suitable concentration of MAA in solution is 3.2 mol/L, the optimal concentration of initiator cerium salt and catalyzer Sulfuric acid is 1.3 × 10⁻² and 0.3 1 mol/L, respectively, the appropriate temperature is 55 °C, and reaction time is 6 h, the grafting degree of PMAA can reach 43.3 g/100 g. The kinetics demonstrating adsorption kinetic of SA by CPS-g-PMAA is fitted PFO model in the first 50 min and is then fitted with the PSO model. The CPS-g-PMAA microsphere adsorbs SA via hydrogen bond interaction, the adsorption capacity reaches 92 mg/g in ethanol. The adsorption amount decreases with the increase of temperature, Freundlich isothermal model is fitted the adsorption experimental data.

Keywords:

• Shikimic acid
• adsorption
• methacrylic acid
• kinetics
• isothermal model

Acknowledgments

This work was supported by the National Science Foundation for Young Scientists of China (21805249); Shanxi Province Science and Technology Foundation (201801D121069) and Engineering for Chemical Engineer and Technology (20190013).