Research On The IPN Type Adsorpbent Resins Based On Poly(Methyl Acrylate)

Interpenetrating polymer network(IPN)technology has become an effective method to modify the polymer blend and develop novel kinds of polymeric materials.In this thesis,three series of new IPN resins with polydivinylbenzene(PDVB)as the first polymeric network,and polyacrylic acid(PAA),polyacrylethylenediamine(PAEM),or poly(acryl acetyl ethylenediamine)(PAAEM)as the second network,were synthesized based on the IPN technology.Their structure,swelling and adsorption properties were studied.The detailed results are as follows:1.Synthesis of hydrophobic/hydrophilic IPN adsorbent resins and their structure and swelling properties(1)Macroporous polydivinylbenzene/poly(methyl acrylate)inter-penetrating polymer network(PDVB/PMA IPN)resins were prepared via suspension polymerization.The two networks of the PDVIB/PMA IPN resins were both hydrophobic.Polydivinylbenzene/poly(acrylic acid)interpenetrating polymer network(PDVB/PAA IPN)resins were obtained through hydrolysis of the PMA networks in methanol with sodium hydroxide and transformation with HC1,of which one network was hydrophobic and the other hydrophilic.DSC of this IPN resin showed only one glass transition temperature at 126.9?,which implied that the two networks of PDVB/PAA IPN resins were completely compatible.Theoretical calculations indicated that the two networks of PDVB/PAA IPN resins become compatible via the interaction between benzene rings and protons of carboxylic grouPDVB.(2)A series of PDVB/PMA IPN resins were prepared under adjusting the condition:different ratio of solvents and non-solvents of PMA in porogen of forming the second network,different crosslinking degree of the second network and the different initial mass ratio of two networks.The resulting PDVB/PMA IPN resins were transferred to polydivinylbenzene/polyacrylethylenediamine interpenetrating polymer network(PDVB/PAEM IPN)resins through aminolysis of PMA with ethylenediamine.The PDVB/PAEM IPN resins were characterized with the moisture holding capacity,weak base exchange capacity,swellingproperties,the specific surface area,pore volume and pore size distribution.DSC results showed that PDVB/PAEM resins appeared two glass transition temperatures,which implied that the two networks were not fully compatible,and theoretical calculations rationlized this result.(3)Macroporous polydivinylbenzene/poly(acryl acetyl ethylene-diamine)interpenetrating polymer network(PDVB/PAAEM IPN)resins were prepared via acetylation of the PDVB/PAEM IPN resins.Moisture holding capacity,weak base exchange capacity,swelling ratio,specific surface area,pore volume,and pore size distribution of the PDVB/PAAEM IPN resins were characterized.The results showed,that the PDVB/PAAEM IPN resins have no weak base grouPDVB anymore(weak base exchange capacity:0 mmol/g).The specific surface area and pore volume were reduced compared with the original PDVB resin.The pore size distribution was from 7.9 nm to 135 nm.Swelling experiments proved that this kind of IPN resin displayed both hydrophilic and hydrophobic properties.2.Adsorption properties of hydrophilic/hydrophobic IPN resins for natural products(1)The adsorption of.theophylline from aqueous solution onto the PDVB/PAA IPN resins was studied.The adsorption isotherms and adsorption isosteres of theophylline on the IPN resins were obtained through experiments.The adsorption enthalpies of different adsorption capacity were calculated from the obtained absorption isosteres according to the Clapeyron-Clausius equation.The possible adsorption mechanism was discussed.(2)The adsorption of naringenin,puerarin and quercetin with the PDVB/PAEM IPN resins were tested respectively to obtain the adsoption thermodynamic function parameters of the IPN resins.The adsorption of naringenin and puerarin from aqueous solution with the PDVB/PAEM IPN resins was an exothermic process.The adsorption isotherm at different temperatures can be fitted well with the Freundlich equation.According to thermodynamic functions,the adsorption enthalpy at the different adsorbed capacity were figured out.Dynamic adsorption and desorption experiments showed that the saturated adsorption capacity of the IPN resins for naringenin could amounted to 45.15 mg/mL resin,while for puerarin,the saturated adsorption capacity was 19.45 mg/mL resin.Both adsorbates could be easily eluted.from the resin completely.The adsorption of quercetin from aqueous solution with the PDVB/PAEM IPN resins was an endothermic process.The adsorption isotherm at different temperatures could be well fitted with Langmuir equation,which indicated that the adsorption of quercetin is belonged to monolayer adsorption.The adsorbed quercetin could not be eluted from the resin with different non-ethanol elution under different desorption conditions,which indicated that some chemical bond might be formed between the resin and quercetin.(3)The adsorption of quercetin from aqueous solution with the PDVB/PAAEM IPN resins was studied.The results showed that the adsorption process is exothermic process.Dynamic adsorption and desorption experiments showed that the saturated adsorption capacity of quercetin was about 8.6 mg/mL wet resin,which was easily eluted with 10%HCl-ethanol elution.