Imidazolium-Functionalized Hypercrosslinked Polymers with Tunable Porosity for Efficient Deterpenation of Essential Oils

The efficient separation of multicomponent natural products is hindered by the difficulty in designing adsorbents capable of capturing different components simultaneously owing to their aligned molecular structures and comparable properties. In our study, a series of imidazolium-functionalized hypercrosslinked polymers were developed, and the porous texture and nitrogen content were notably altered by adjusting the molar ratio between the monomer and crosslinker, alongside variations in the length and rigidity of the crosslinkers. Owing to the accessible porosities and abundant adsorption sites, the polymers displayed a rapid adsorption rate and high capacities of 313 mg·g^–1 for citral and 281 mg·g^–1 for linalool, with an oxyterpene/terpene selectivity of 2.3. Featuring an effective liquid breakthrough performance and rapid regeneration capabilities, they demonstrated considerable potential for practical deterpenation applications. This study may provide insights into controlling the pore structure and chemistry of ionic porous polymers, potentially enabling their application in separating valuable natural products with similar structures.