Monodisperse poly (chloromethylstyrene divinylbenzene) particles were prepared by a two-step swelling method. It was demonstrated that the packings have comparative advantages for biopolymer separation with high colum...Monodisperse poly (chloromethylstyrene divinylbenzene) particles were prepared by a two-step swelling method. It was demonstrated that the packings have comparative advantages for biopolymer separation with high column efficiency, low interstitial volume and low back pressure to the packings prepared with suspension polymerization method. Using size exclusionchromatography and weak ion exchange chromatography as examples, it was shown that these packings could be modified chemically more easily than poly (styrene divinylbenzene) packings.展开更多
Poly(divinylbenzene) (PDVB) microcapsules containing octadecane (OD) (PDVB/OD) used as heat storage material were synthesized by suspension polymerization at 70 Microencapsulation, Microcapsule, Heat Storage Material,...Poly(divinylbenzene) (PDVB) microcapsules containing octadecane (OD) (PDVB/OD) used as heat storage material were synthesized by suspension polymerization at 70 Microencapsulation, Microcapsule, Heat Storage Material, Octadecane, Suspension Polymerization, Poly(Divinylbenzene)C using benzoyl peroxide and polyvinyl alcohol as initiator and stabilizer, respectively. Thermal properties and stability of PDVB/OD microcapsules were determined using differential scanning calorimeter (DSC) and thermogravimetric analyzer. The morphology and structure of microcapsules were characterized by optical microscope, scanning electron microscope and fourier transform infrared spectrophotometer. From DSC analysis, the melting temperature of encapsulated OD (28oC) was almost the same as that of bulk OD (30oC) while it was quite different in the case of the solidification temperature (19oC and 25oC for encapsulated and bulk OD, respectively). The latent heats of melting (184.0 J/g-OD) and solidification (183.2 J/g-OD) of encapsulated OD were reduced from those of bulk OD (241.7 and 247.0 J/g, respectively). However, the prepared PDVB/OD microcapsules are able to be used for heat storage applications.展开更多
Hyperbranched poly(methyl methacrylate)s (HPMMAs) have been successfully prepared by atom transfer radical copolymerization of MMA and divinylbenzene (DVB).Kinetic study shows complete consumption of the initiator in ...Hyperbranched poly(methyl methacrylate)s (HPMMAs) have been successfully prepared by atom transfer radical copolymerization of MMA and divinylbenzene (DVB).Kinetic study shows complete consumption of the initiator in 0.5 h,and relatively low polymerization rate when DVB content in the feed was high.By analyzing MALDI-TOF spectra of the resulting copolymers,the linear A n B (n=0,1,2,3) oligomers were formed in 0.5 h of polymerization,and then the oligomers reacted each other to form dimers,further reactions produced HPMMA.The SEC and NMR spectroscopies were used to trace the polymerization,and the results demonstrate that small amount of the branching reactions occur in the initial polymerization,and the branched polymers are significantly generated past a certain conversion depending upon the feed ratios.Raising the content of DVB in the monomer mixture can increase the pendent vinyl groups of the linear oligo-inimers,leading to gelation at low MMA conversion.展开更多
An approach for preparation of a novel composite anion exchanger composed of polystyrene/divinylbenzene (PS/DVB) beads and quaternized nanodiamods (QND) were proposed. Oxidized nanodiamonds (OND) were quaternized by t...An approach for preparation of a novel composite anion exchanger composed of polystyrene/divinylbenzene (PS/DVB) beads and quaternized nanodiamods (QND) were proposed. Oxidized nanodiamonds (OND) were quaternized by the condensation polymerization between methylamine (MA) and 1,4-butanediol diglycidyl ether (BDDE), which were characterized by Fourier transform infrared (FTIR) spectra, X-ray phtoelectron spectroscopy (XPS), thermogravimetric analysis (TGA). QND with layers of cationic polyelectrolyte was attached onto the surface of sulfonated PS/DVB beads electrostatically. Subsequently, hyperbranched reaction of QND agglomerated on the PS/DVB bead surface was performed by the alternate reaction between MA and BDDE to increase the exchange capacity. The composite anion exchanger showed good stability in organic solvent and a wide pH range.The surface of these microspheres was characterized by scanning electron microscopy. In addition, ion exchange selectivity and separation efficiency of the anion exchangers were assessed using the mixtures of anions (F,Cl,NO_2,Br,NO_3,HPO_4~2 and SO_4~2) with carbonate/bicarbonate as eluent, and the anion exchanger with high exchange capacity could be used to analyze chloride in aqueous solution with high concentration of fluoride. This work explores the potential of nanodiamods as an agglomerated material for ion chromatography stationary phases for the separation of inorganic anions.展开更多
The chloromethyl groups have been introduced into commercial S/DVB copolymer matrixes via interpenetratingpolymer networks (IPN) synthesis. The procedure involves impregnation of the Amberlite XAD-4 adsorbent,with use...The chloromethyl groups have been introduced into commercial S/DVB copolymer matrixes via interpenetratingpolymer networks (IPN) synthesis. The procedure involves impregnation of the Amberlite XAD-4 adsorbent,with use of the vinylbenzyl chloride (VBC) and divinylbenzene (DVB) monomers mixture, and suspensionpolymerization process. The syntheses were evaluated by FT-IR spectra and SEM analyses and furthermore bychlorine content determination as well as characterization of porous structure by nitrogen adsorption at liquid nitrogentemperature. Designed synthesis approach allowed determining organic and water phases composition. Furthermore,impact of an excess of the organic phase removal method has been investigated. Basing on the obtainedresults it could be stated that the chloromethyl groups, derived from VBC monomer, were successfully introducedinto the XAD-4 structure. Captured SEM images revealed significant changes in the beads’ surface morphology afterpolymerization processes. The presented studies reveal designed and executed synthesis processes, which involvethe use of a proper water phase and excess of organic phase removal. Observed changes in the beads’ morphologysuggest that introduced functionalities are concentrated on the porous surface of the XAD-4 adsorbent.展开更多
文摘Monodisperse poly (chloromethylstyrene divinylbenzene) particles were prepared by a two-step swelling method. It was demonstrated that the packings have comparative advantages for biopolymer separation with high column efficiency, low interstitial volume and low back pressure to the packings prepared with suspension polymerization method. Using size exclusionchromatography and weak ion exchange chromatography as examples, it was shown that these packings could be modified chemically more easily than poly (styrene divinylbenzene) packings.
文摘Poly(divinylbenzene) (PDVB) microcapsules containing octadecane (OD) (PDVB/OD) used as heat storage material were synthesized by suspension polymerization at 70 Microencapsulation, Microcapsule, Heat Storage Material, Octadecane, Suspension Polymerization, Poly(Divinylbenzene)C using benzoyl peroxide and polyvinyl alcohol as initiator and stabilizer, respectively. Thermal properties and stability of PDVB/OD microcapsules were determined using differential scanning calorimeter (DSC) and thermogravimetric analyzer. The morphology and structure of microcapsules were characterized by optical microscope, scanning electron microscope and fourier transform infrared spectrophotometer. From DSC analysis, the melting temperature of encapsulated OD (28oC) was almost the same as that of bulk OD (30oC) while it was quite different in the case of the solidification temperature (19oC and 25oC for encapsulated and bulk OD, respectively). The latent heats of melting (184.0 J/g-OD) and solidification (183.2 J/g-OD) of encapsulated OD were reduced from those of bulk OD (241.7 and 247.0 J/g, respectively). However, the prepared PDVB/OD microcapsules are able to be used for heat storage applications.
基金National Natural Science Foundation of China for financial support(50673086,50633010)
文摘Hyperbranched poly(methyl methacrylate)s (HPMMAs) have been successfully prepared by atom transfer radical copolymerization of MMA and divinylbenzene (DVB).Kinetic study shows complete consumption of the initiator in 0.5 h,and relatively low polymerization rate when DVB content in the feed was high.By analyzing MALDI-TOF spectra of the resulting copolymers,the linear A n B (n=0,1,2,3) oligomers were formed in 0.5 h of polymerization,and then the oligomers reacted each other to form dimers,further reactions produced HPMMA.The SEC and NMR spectroscopies were used to trace the polymerization,and the results demonstrate that small amount of the branching reactions occur in the initial polymerization,and the branched polymers are significantly generated past a certain conversion depending upon the feed ratios.Raising the content of DVB in the monomer mixture can increase the pendent vinyl groups of the linear oligo-inimers,leading to gelation at low MMA conversion.
基金financially supported by the National Natural Science Foundation of China (No. 51503182)Analysis and Measurement Foundation of Zhejiang Province(No. 2017C37064)+1 种基金Zhejiang Provincial Natural Science Foundation (No. LQ15C200006)Zhejiang University of Technology Natural Science Foundation (No. 2014XY002)
文摘An approach for preparation of a novel composite anion exchanger composed of polystyrene/divinylbenzene (PS/DVB) beads and quaternized nanodiamods (QND) were proposed. Oxidized nanodiamonds (OND) were quaternized by the condensation polymerization between methylamine (MA) and 1,4-butanediol diglycidyl ether (BDDE), which were characterized by Fourier transform infrared (FTIR) spectra, X-ray phtoelectron spectroscopy (XPS), thermogravimetric analysis (TGA). QND with layers of cationic polyelectrolyte was attached onto the surface of sulfonated PS/DVB beads electrostatically. Subsequently, hyperbranched reaction of QND agglomerated on the PS/DVB bead surface was performed by the alternate reaction between MA and BDDE to increase the exchange capacity. The composite anion exchanger showed good stability in organic solvent and a wide pH range.The surface of these microspheres was characterized by scanning electron microscopy. In addition, ion exchange selectivity and separation efficiency of the anion exchangers were assessed using the mixtures of anions (F,Cl,NO_2,Br,NO_3,HPO_4~2 and SO_4~2) with carbonate/bicarbonate as eluent, and the anion exchanger with high exchange capacity could be used to analyze chloride in aqueous solution with high concentration of fluoride. This work explores the potential of nanodiamods as an agglomerated material for ion chromatography stationary phases for the separation of inorganic anions.
文摘The chloromethyl groups have been introduced into commercial S/DVB copolymer matrixes via interpenetratingpolymer networks (IPN) synthesis. The procedure involves impregnation of the Amberlite XAD-4 adsorbent,with use of the vinylbenzyl chloride (VBC) and divinylbenzene (DVB) monomers mixture, and suspensionpolymerization process. The syntheses were evaluated by FT-IR spectra and SEM analyses and furthermore bychlorine content determination as well as characterization of porous structure by nitrogen adsorption at liquid nitrogentemperature. Designed synthesis approach allowed determining organic and water phases composition. Furthermore,impact of an excess of the organic phase removal method has been investigated. Basing on the obtainedresults it could be stated that the chloromethyl groups, derived from VBC monomer, were successfully introducedinto the XAD-4 structure. Captured SEM images revealed significant changes in the beads’ surface morphology afterpolymerization processes. The presented studies reveal designed and executed synthesis processes, which involvethe use of a proper water phase and excess of organic phase removal. Observed changes in the beads’ morphologysuggest that introduced functionalities are concentrated on the porous surface of the XAD-4 adsorbent.
