Phenolic hydroxyl functionalized hyper-crosslinked polymers and their efficient adsorption

•Phenolic hydroxyl modified hyper-crosslinked polymers were synthesized.•The polymers had high specific surface area with predominant microporosity.•The polymer was efficient for adsorption of berberine hydrochloride with the capacity of 505.42 mg/g.•The electrostatic interaction, hydrogen bonding, and π-π stacking were the primary driving forces.