Resin Synthesis

The synthesis of gel-type resins typically employs suspension polymerization as the core process. In this method, the main monomer (e.g., styrene) and the key crosslinking agent (e.g., divinylbenzene, DVB) are dissolved in an oil phase. Under the action of an initiator, the oil phase is dispersed into an aqueous phase containing a stabilizer to form uniform droplets. Subsequently, free radical polymerization proceeds under heating conditions: monomer molecules undergo chain propagation within the droplets, while DVB molecules connect adjacent polymer chains through their double bonds, forming a three-dimensional crosslinked network structure. Upon completion of the reaction, crosslinked polymer beads (commonly referred to as “white beads”) are obtained. This basic skeleton itself has no specific functionality and requires further chemical functionalization to introduce the desired active groups, ultimately yielding gel-type resins with ion exchange or other specific functions.

The synthesis of macroporous resins typically employs suspension polymerization as the core process. By adding a porogen to the mixed system of monomer (e.g., styrene) and crosslinking agent, an oil phase is formed and dispersed into an aqueous phase containing a dispersant. Under the action of an initiator, through gradient temperature-programmed polymerization, the monomers crosslink and solidify while the porogen is retained within the polymer network. After polymerization is complete, the porogen is removed by solvent extraction or washing, forming a polymer skeleton with a permanent three-dimensional pore structure (i.e., “white beads”). The pore size and specific surface area can be precisely controlled by the type of porogen (good solvent/poor solvent) and its proportion. Subsequent chemical functionalization is required to endow the resin with specific properties.