Hyper-cross-linked polymers functionalized with primary amine and its efficient adsorption of salicylic acid from aqueous solution

Chemically functionalized hyper-cross-linked polymers (HCLPs) are desired for efficient adsorption of aromatic compounds. Herein primary amine (–NH2) was indirectly functionalized on the HCLPs and the aniline-modified HCLPs namely An-HCLP was assessed by adsorption of salicylic acid from aqueous solution. The results indicated that 2.24 mmol·g−1 of –NH2 groups were uploaded and they are greatly beneficial for the adsorption, the enthalpy change was figured out to be −35.27 kJ·mol−1, and multiple interactions including acid-base interaction and hydrogen bonding are the main driving forces. Moreover, An-HCLP owned hierarchical porosity with continuous micropores and mesopores, which endowed them with fast kinetic adsorption, 55 min is sufficient for the adsorption attaining equilibrium, and the pseudo-second-order rate equation describes the kinetic very well with the kinetic constant (k2) of 1.266 × 10−3 g·mg−1·min−1.