Synthesis And Adsorption Property Of Polystyrene-Isocynauric Acid Resin Based On St-BVPE Copolymer

Macroporous hypercrosslinked polystyrene adsorbent resins are polystyrenes with more than50%structure units of styrene are crosslinked, which are widely used due to their high specific surface area and abundant of micropores, excellent swelling performance in solvents and non-solvents of polystyrene, and distinguished adsorption performance. However, most of the commercial macroporous hypercrosslinked polystyrene adsorbent resins are produced by post-crosslinking of the styrene(St)-divinylbenzene(DVB) copolymer. The difference of reactivity ratios between St and DVB results in the structure inhomogeneity of the St-DVB copolymer, which leads to the structure inhomogeneity of hypercrosslinked polystyrene adsorbent resins made from St-DVB copolymer and causes some problems in adsorption performance when the hypercrosslinked resins are used in adsorption and separation.In order to overcome the problems resulted from the structure inhomogeneity of St-DVB copolymer, the following work was conducted in this dissertation.1. A divinyl crosslinking agent1,2-bis(p-vinylphenyl)ethane, which possesses two vinyl groups with reactivity ratios of1in free radical copolymerization with styrene, was synthesized via the Grignard coupling reaction of p-chloromethylstyrene, and its structure was confirmed by1HNMR.2. St-BVPE copolymer and St-DVB copolymer were synthesized by free radical copolymerization of monomer of St and crosslinking agent of BVPE or DVB in the presence of porogen. After chloromethylation of the two copolymers, the chloromethylated copolymers were reacted with isocyanuric acid to synthesize macroporous hypercrosslinked polystyrene-isocyanuric acid resins based on St-BVPE copolymer and St-DVB copolymer (shorted as BVPE resin and DVB resin). Chemical structure of the BVPE resin and DVB resin was characterized by FT-IR spectra. Pore structure of the dried resins was tested by TriStar3000surface area and porosity analyzer. Moisture holding capacity of the wet resins was also tested. The results showed that isocyanuric acid was successfully bonded to the two resins, the average pore size of BVPE resin(134.7nm) was larger than that of the DVB resin(100.1nm), and the moisture holding capacity of BVPE resin(54.0%) was higher than that of the DVB resin(49.7%).3. The static adsorption property and dynamic adsorption/desorption property of the BVPE resin and DVB resin for phenol, theophylline and caffeine from aqueous solution were tested. The results showed that:(1) The adsorption capacity of the BVPE resin was30-200%more than that of the DVB resin.(2) the dynamic saturated adsorption capacity of the BVPE resin for400mg/L caffeine amounted to50.21mg/g and the desorption rate was99.27%; the dynamic saturated adsorption capacity of the DVB resin for400mg/L caffeine was16.41mg/g and the desorption rate was97.90%. Both of the dynamic saturated adsorption capacity and desorption rate of BVPE resin was more than those of the DVB resin.