| Hypercrosslinked adsorbent resins are capable of adsorbing aromatic compounds effectively due to their high specific surface area.Amide modified macroporous resins can adsorb polar organic compounds with hydrogen bond donors selectively since the amide groups are hydrogen bond acceptors.If appropriate amide groups were introduced to the hypercrosslinked adsorbent resins,the resins would show high selectivity and high adsorption capacity for aromatic compounds with hydrogen bond donors.Hence acetanilide modified hypercrosslinked adsorbent resins were prepared and characterized,and their adsorption performances for some organic compounds with hydrogen bond donors were investigated in this dissertation.The structure and adsorption performances of the resins were studied.The main contents of this dissertation are as following:1.By adding acetanilide with the mass amount of 0%,8%,10%,and15%as compared with the chloromethylated polystyrene resin(CMPS),respectively,auto-cross-linked polystyrene resin HA0 and acetanilide modified polystyrene resins HA8,HA10,and HA15 were prepared from CMPS through the Friedel-Crafts reaction between the chloromethyl groups and benzene rings of the resin or the acetanilide molecules in the solvent of 1,2-dichloroethane.By using dichloromethane as external crosslinker,acetanilide modified hypercrosslinked adsorbent resins HA8D,HA10D,and HA15D were prepared from HA8,HA10,and HA15through the double Friedel-Crafts reaction between dichloromethane and benzene rings of the resin,respectively.Structure of the resins was characterized by FT-IR spectra,chlorine and nitrogen content analysis,moisture holding capacity measurement,and surface area and porosity analysis,and the results showed that acetanilide was successfully bonded to HA8D,HA10D,and HA15D,and specific surface area of the resins was enhanced obviously after post-crosslinking with dichloromethane.2.Adsorption isotherms of o-nitrophenol,p-nitrophenol,phenol,paracetamol,caprolactam and acetanilide onto the acetanilide modified polystyrene resins and the acetanilide modified hypercrosslinked adsorbent resins from aqueous solution were determined.Effects of the amide groups and pore structure on adsorption properties were investigated,and the adsorption mechanisms were proposed.The results showed that HA8 displayed the best static adsorption performance among the acetanilide modified polystyrene resins,and HA8D displayed the best static adsorption performance among the acetanilide modified hypercrosslinked adsorbent resins.The static adsorption performance of HA8D was better than that of HA0 and HA8,which might result from the higher specific surface area and appropriate amide groups of HA8D.The Langmuir and Freundlich isotherm equations were used to fit the static adsorption data of the six adsorbates onto HA8D,and the results showed that the Langmuir isotherm equation fitted better than the Freundlich isotherm equation.The adsorption process was spontaneous,exothermic and entropy reducing.The adsorbates could be desorbed effectively from HA8D by rinsing with ethanol,and the regenerated HA8D showed excellent reusing performance.3.In order to synthesize acetanilide modified hypercrosslinked adsorbent resins with higher skeleton density so as to fit the demand of application,HA8D was reacted chlorine generated in situ to obtain a chlorinated acetanilide modified hypercrosslinked adsorbent resin HA8DC.Chlorine content,skeleton density,moisture holding capacity,and surface area and porosity of HA8DC were tested,and adsorption isotherms of o-nitrophenol,p-nitrophenol,and phenol onto HA8DC from aqueous solution were determined.The results showed that the chlorine content increased from 2.03%of HA8D to 16.65%of HA8DC,the skeleton density increased from 1.16 of HA8D to 1.33 of HA8DC,which implied HA8D was chlorinated successfully and the resin with higher skeleton density was obtained.The specific surface area decreased from1009 m~2/g of HA8D to 662 m~2/g of HA8DC,the pore volume decreased from 1.07 cm~3/g of HA8D to 0.73 cm~3/g of HA8DC,and the average pore diameter increased somewhat.The adsorption capacities of the three adsorbates on HA8DC were all lower than the corresponding capacities on HA8D,but the capacities were high enough yet.The Langmuir and Freundlich isotherm equations were used to fit the static adsorption data of the three adsorbates on HA8DC,and the results showed that the Langmuir isotherm equation fitted better than the Freundlich isotherm equation.The adsorption process was spontaneous,exothermic and entropy reducing. |
