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1.
Cation-exchange resins have been synthesized through the condensation of N-vinylcarbazole and poly(N-vinylcarbazole) with furfural in presence of anhydrous AlCl3 and subsequent sulfonation of the condensates. The resins have been characterized in respect to their polyfunctionality, exchange capacity, and thermal stability.  相似文献   

2.
Crosslinked copolymers of N-vinylcarbazole and poly N-vinylcarbazole) and formaldehyde have been phosphorylated using PCl3 and anhydrous AlCl3 under different conditions. The cation exchange resins, thus obtained, have been characterized by elemental analyses, evaluation of total ion-exchange capacities and salt-splitting capacities, pH metric titration behavior, and IR analysis. The phosphorylated resin exhibites significantly better thermal stability than the corresponding sulfonated N-vinylcarbazole–formaldehyde cation exchange resin or the unmodified N-vinylcarbazole–formaldeyde copolymer, as well as the phosphorylated poly(N-vinylcarbazole). The phosphorylated resins also behave as polymeric dyes with pH dependent color change. Possible explanations for color change and ion-exchange capacity differences have been attempted on the basis of the structural characteristics of the resins.  相似文献   

3.
Thermal stabilities of the crosslinked N-vinylcarbazole/poly(N-vinylcarbazole)-furfural polymers and of the phosphonic acid resins prepared thereform were studied by thermogravimetric analysis. The overall thermal stability of the crosslinked polymers is greater than the same for poly(N-vinylcarbazole) and is further improved upon phosphorylation. The resins are stable in 5N acids and water at 100°C. Isothermal oxidative degradation studies of the resins indicate significant increase in the capacities. pH metric titration of the resins shows the presence of mono and dibasic phosphonic acid groups. The resins realize about 90% of their capacities within 2 min of equilibration.  相似文献   

4.
A cross-linked copolymer of poly-N-vinylcarbazole and formaldehyde has been sulfonated to yield a cation exchange resin. The resin has been characterized by elemental analysis and by evaluation of total and salt-splitting capacities and pH-metric titration behavior. The resin has improved capacity (ion exchange) relative to other N-vinylcarbazole based resins and behaves as a polymeric dye.  相似文献   

5.
A condensation product based on phthalic anhydride and N-vinylcarbazole has been prepared and processed into a sulfonic acid cation exchange resin. The resin produced has been characterized by measuring its total and salt splitting capacities and by studying its thermal characteristics, rate of exchange, and behavior to pH metric titration.  相似文献   

6.
A copolymer of N-vinylcarbazole and divinylbenzene has been sulfonated to yield a cation exchange resin of improved thermal properties compared to other vinylcarbazole-based resins. The resin has been characterized by measuring its total and salt-spliting capacities, pH metric titration, and thermal stability characteristics.  相似文献   

7.
A crosslinked polymer has been synthesized from the reaction of N-vinylcarbazole and formalin in toluene in the presence of dry HCl gas. The copolycondensate is insoluble in all common solvents for poly-N-vinylcarbazole, and exhibits higher thermal stability than the unmodified poly-N-vinylcarbazole. However, this polymer is less thermally stable than the corresponding furfural modified poly-N-vinylcarbazole. A mechanism for the overall reaction has been suggested and the factors affecting the synthesis have been discussed.  相似文献   

8.
Chemically modified polystyrenes based on the condensation of polystyrene with phthalic anhydride, trimellitic anhydride, and cis-1,2,3,6-tetrahydrophthalic anhydride have been processed into sulfonic acid cation exchange resins. The effects of variation of sulfuric acid amount and the temperature of sulfonation on the synthesis and the ion-exchange capacities of the resins have been established. The resins have finally been characterized with respect to their structures by IR and elemental analysis data. The total ion exchange capacity as well as the salt-splitting capacity and the pH-metric titration characteristics of these resins have also been determined. These resins posses better ion-exchange capacities than the conventional styrene based resins.  相似文献   

9.
It is well known that cation exchange membranes, having a very thin layer of a cationic polyelectrolyte on the membrane surface, have preferential permselectivity for monovalent cations in a monovelent-divalent cations system. We studied the relationship between preferential permselectivity and molecular structure of the cationic polyelectrolyte. Grafted poly(4-vinyl-N-methylpyridinium-iodide) was used and was compared with poly(4-vinyl-N-methylpyridiniumiodide). The backbone polymers were poly(styrene-co-p-benzylstyrene) and poly(benzyl), onto which 4-vinylpyridine was grafted by anionic polymerization and then quaternized with CH3I. The grafted poly(4-vinyl-N-methylpyridinium-iodide) is effective in making the cation exchange membrane preferentially permselevtive for Na+ - Ca2+ system and is more preferable than poly(4-vinyl-N-methylpyridinium-iodide) in terms of electric resistance of the membrane. However, the relationship between the molecular structure of the cationic polyelectrolyte and the durability of the preferential permselectivity is not clear.  相似文献   

10.
The electrolysis of N-vinylcarbazole in the solution of quaternary ammonium salts in dichloroethane leads to polymer formation in the anolyte. The effect of monomer concentrations, current levels, and nature of supporting electrolytes on the polymerization has been investigated. The polymerization is free radical with bromide salt and cationic with perchlorate or hexachloroantimonate salt. The poly(N-vinylcarbazole) gets oxidized at the anode and can be cycled between the oxidized and neutral states. The oxidized polymers at the electrode may exhibit electrical conductivity.  相似文献   

11.
Zinc containing edible oil (coconut oil) based polyesteramide resins were synthesized by condensation polymerization between N,N′-bis (2-hydroxyethyl) coconut oil fatty amide (HECA), Zn (OH)2 and citric acid/tartaric acid. The structural studies were carried out by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. Standard laboratory methods were used to study the physiochemical characteristics like acid value, hydroxyl value, saponification value, iodine value, specific gravity, and viscosity. The thermal behaviour of the polymers was analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Both polymers were examined for antifungal and antibacterial properties and the results were compared with a standard drug. In the case of fungi, the growth curve (turbidometric measurement) was performed using a conventional spectrophotometer for the tartaric polymer, which showed higher biological activity against one of the Candida species.  相似文献   

12.
The polymerization of N-vinylcarbazole was conducted in bulk in presence of ZnO without any external initiator and a nanocomposite of poly(N-vinylcarbazole)–ZnO (PNVC–ZnO) was isolated from the system. The polymerization of N-vinylcarbazole by ZnO impregnated with acetylene black (AB) and Fe3+ was also conducted to isolate the respective AB and Fe3+ loaded PNVC–ZnO composites, PNVC–ZnO(AB) and PNVC–ZnO(Fe3+). The formation of the poly(N-vinylcarbazole) in these systems was confirmed by FTIR, UV–vis and emission spectroscopic analysis. TGA, DSC and SEM characteristics of these composites were evaluated in details. XRD analysis revealed no crystanillity in poly(N-vinylcarbazole) moiety. PNVC–ZnO was nonconducting but PNVC–ZnO(AB) and PNVC–ZnO(Fe3+) systems exhibited conductivities in the range 0.12 and 10−3 S/cm respectively. A carbocationic propagation pathway was suggested to explain the initiation of N-vinylcarbazole by Zn++ moiety in ZnO. Kinetic studies revealed that the polymerization is first order with respect to ZnO and the monomer concentration respectively.  相似文献   

13.
Sulfonated polysulfone (SPS) membranes were prepared, and the gas‐transport properties of the resulting ionic polymers were examined. Gas‐transport measurements were made on dense films of these polymers with a continuous flow technique. The sulfonation of polysulfone and the metal‐cation exchange of SPS were confirmed with Fourier transform infrared spectroscopy and electron spectroscopy for chemical analysis. The SPS membranes exchanged with the monovalent metal ions showed higher permeability coefficients than the SPS membranes exchanged with the multivalent metal ions, whereas the selectivities of all the metal‐cation‐exchanged sulfonated polysulfone (MeSPS) membranes for O2/N2 and CO2/N2 gas pairs were higher than those of SPS membranes. When the MeSPS membranes with metal cations of similar ionic radii were compared, the ideal selectivities of O2/N2 and CO2/N2 through MeSPS with divalent cations were higher than those through MeSPS with monovalent cations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2611–2617, 2002  相似文献   

14.
The polymerization of N-vinylcarbazole initiated with NO2 and SO2 in dichloroethane has been studied. The kinetics of polymerization were followed gravimetrically. The Polymerization is fast with NO2 but a relatively slow rate was obtained with SO2. The polymerization with these gases appears to be initiated by a charge transfer mechanism.  相似文献   

15.
A nanoreactor effect is found that consists in a considerable (two orders of magnitude) increase in the rate of ion exchange in sulfonated calixarene-containing polymers. The kinetics of ion exchange in network calixarene-containing polymers with sulfonic acid and phenolic ionogenic groups is studied. It is shown that the interaction of these polymers with aqueous solutions of LiCl, NaCl, AgNO3, LiOH, NaOH, and (CH3)4NOH is controlled by ion diffusion in the polymeric phase. An analytical dependence of the conversion on an interdiffusion coefficient and the time of ion exchange in bifunctional cation exchangers is derived using the spherical-layer model.  相似文献   

16.
Ion‐exchange polymers were used successfully in water‐treatment operations. In this study, three ion‐exchange resins based on 4‐vinylpyridine and divinylbenzene functionalized with N‐oxide groups were obtained. Their ion‐adsorption properties were measured in solutions containing chromium at concentrations of 4 and 500 ppm with column and batch equilibrium techniques. The removal efficiency of the chromium ions with HCl was observed to increase after the protonation of the N‐oxide groups. The resins could be reused after 10 cycles with the metal removal efficiency maintained at higher than 95%. These studies evidenced a strong correlation between the morphology and ionic group content in the resin and its chromium ion sorption capability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008  相似文献   

17.
It was pointed out in previous papers that both cationic and anionic polymerization might be involved simultaneously in grafting onto trunk polymers containing ? COOH or ? SO3Na. The graft copolymerization of β-Propiolactone (βPL)–N-vinylcarbazole (NVCZ) onto styrene-divinylbenzene copolymers containing carboxylic acid, sulfonic acid, and their salts was carried out in order to distinguish between the polymers produced by anionic and cationic mechanisms. The polymer obtained by the polymerization of βPL–NVCZ with BF3·OEt2, a typical cationic catalyst, consisted mainly of NVCZ units, but the polymer obtained with BuLi, a typical anionic catalyst, consisted mainly of βPL units. In the graft copolymerization of NVCZ–βPL onto trunk polymer containing ? COOH, the NVCZ contents of the branch polymer and the tolueneinsoluble fraction were estimated to be ca. 50 mole-%; therefore these polymers were produced by both cationic and anionic mechanisms. In the case of graft copolymerization onto the trunk polymer containing SO3Na, it was found that both cationic and anionic polymerization also occurred simultaneously.  相似文献   

18.
Sustainable resol-type resins [phenol–furfural–glucose (PFuG), phenol–furfural (PFu), and phenol–glucose resins] were synthesized via alkali catalysis. The chemical structures of the PFuG resins, which had different molar ratios of glucose to furfural, were analyzed by 1H-NMR and Fourier transform infrared spectroscopy. A possible mechanism for formation of the PFuG resin was proposed. The crosslinking curing behaviors of the PFuG resins were examined by differential scanning calorimetry analysis. The performance of the PFuG resins as wood adhesives was studied. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47732.  相似文献   

19.
Trimellitic anhydride and pyromellitic dianhydride have been polycondensed with Cu(II)–phenanthroline complex as a comonomer in the presence of anhydrous ZnCl2 under selective conditions. Elemental diffuse reflectance and infrared spectroscopic and X-ray diffraction (XRD) analysis data of these polymers have been correlated with the tentative structure Proposed for these polycondensates. Thermal stability and dielectric and conductivity characteristics of these polycondensates have been evaluated to understand the effect of the ligand and the anhydride moieties on these properties. Unlike the polymer-anchored 3d-metal complexes, these polycondensates fail to initiate the cationic polymerization of N-vinylcarbazole. © 1995 John Wiley & Sons, Inc.  相似文献   

20.
The microwave-assisted syntheses of anion exchange resins were carried out in the presence of selected organic solvents and amines, applying variable radiation density. The polymers were used for sorption of ReO4, after which, the collected results were set together with the applied synthesis parameters. The greatest Re(VII) sorption capacity of 470 mg Re g?1 was revealed by a resin obtained within 10 min in the presence of N,N-dimethylformamide and 2-methylimidazole at power of 160 W. The outcome of the present research constitutes a set of guides allowing to enhance the resource-efficiency of the process.  相似文献   

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