The Novel Boric Acid Modified Material As Micro Separation Plant for 1,3-BDO: Adsorption Behavior and Mechanism

As an important fine chemical, the research on adsorption separation of 1,3-butanediol (1,3-BDO) is still blank. In this study, the novel boric acid modified polystyrene material PS-BA-1 (boric acid content 1.169 mmol center dot g- 1) was synthesized via introducing boric acid pinacol ester into the matrix and deprotection reaction. The adsorption capacity of PS-BA-1 for 1, 3-BDO reached 0.422 mmol center dot g- 1 (water) and 0.947 mmol center dot g- 1 (EtOH), while that of commercial resin CHA-111 was only 0.258 mmol center dot g- 1 and 0.012 mmol center dot g- 1. Interestingly, Freundlich equation could better describe the adsorption process in water (R2 >= 0.989) while Langmuir equation fit the EtOH system with higher correlation coefficients (R2 >= 0.990), respectively, indicating the adsorption process was reversible and non-ideal in water. Meanwhile, the kinetic adsorption could be better modeled by Pseudo-second-order equation (R2water = 0.991, R2EtOH = 0.990) and the k2-water (21.094*10-2) was higher than that of EtOH (3.516*10-2), demonstrating the mass transfer diffusion rate in water was faster. The breakthrough point for PS -BA-1 was 160 -162 BV in EtOH solution which was about twice of that of water system (83 -85 BV), and the column could be completely regenerated. Subsequently, PS-BA-1 was more conducive to the separation of 1,3-BDO in binary competitive experiments, indicating six-member borate esters was more stable binding struc-ture. The computational chemistry further certified the adsorption selectivity between 1,3-BDO and PS-BA-1 as Delta G was lowest (-11.456 kcal center dot mol-1).