Highly functionalized polystyrene by direct metalation?carboxylation

Nemes, Sándor; Borbély, János; Borda, J M; Kelen, Tibor

doi:10.1007/bf00296020

Cited by 6 publications

(8 citation statements)

References 16 publications

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“…[8][9][10] The peaks at 1.2-2.4 and 6.4-7.4 ppm originate from the aliphatic and aromatic protons of the styrene repeating units in the polymer, respectively. Furthermore, 13 C NMR data of our helices agree well with those reported for polystyrene in the literature [ Figure 3(b)]. [11][12][13] The 13 C NMR spectrum can be separated into two different regions; between 120 and 150 ppm, four different peak areas can be observed for the five aromatic carbons in the polystyrene repeating unit.…”

Section: Resultssupporting

confidence: 80%

“…Furthermore, 13 C NMR data of our helices agree well with those reported for polystyrene in the literature [ Figure 3(b)]. [11][12][13] The 13 C NMR spectrum can be separated into two different regions; between 120 and 150 ppm, four different peak areas can be observed for the five aromatic carbons in the polystyrene repeating unit. A second region between 40 and 45 ppm contains two peak areas for the methylene and methine carbons.…”

Section: Resultssupporting

confidence: 80%

“…The elementary composition of the spiral morphologies was determined by energy-dispersive X-ray (EDX) analysis using an EDX microanalyzer from EDAX on a FEI Quanta 400T scanning microscope at 15 kV. Proton and carbon nuclear magnetic resonance spectra ( 1 H NMR, 13 C NMR) of several helices were recorded in CDCl 3 on a Bruker Avance 300 instrument working at 300 MHz. Thermogravimetry (TGA) was performed in air atmosphere from 25 up to 500 8C and at a heating rate of 10 8C min À1 using a Mettler Toledo TG50 thermal analysis system equipped with a TC15 controller.…”

Section: Experimental Partmentioning

confidence: 99%

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Chiral Polymer Helices with Shape Identical to Previously Reported Helical Calcium Carbonate Morphologies

Glaab

Kellermeier

Kunz

2007

Macromol. Rapid Commun.

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Helices with highly ordered substructures were found sporadically during precipitation of self‐assembled silica‐barium carbonate “biomorphs”. Identical morphologies are already known and cited in the literature as helical calcite structures, formed by the influence of chiral phosphoserine copolypeptides. Yamamoto et al. claim that the handedness of the helices can be tuned by the chirality of the amino acids in the phosphoserine copolypeptides. Optical and scanning electron microscopy, energy‐dispersive X‐ray analysis, thermogravimetry, as well as proton and carbon nuclear magnetic resonance were performed on selected twisted ribbons, proving that these helical superstructures—in shape identical to the helical calcite morphologies reported by Yamamoto et al.—do not consist of inorganic material but of an organic polymer, representing plastic abrasion caused by scratching glass pipettes along plastic surfaces.magnified image

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Section: Resultssupporting

confidence: 80%

Section: Resultssupporting

confidence: 80%

Section: Experimental Partmentioning

confidence: 99%

See 1 more Smart Citation

Chiral Polymer Helices with Shape Identical to Previously Reported Helical Calcium Carbonate Morphologies

Glaab

Kellermeier

Kunz

2007

Macromol. Rapid Commun.

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“…In this work, we have reported a new way of preparing negatively charged carboxylated polystyrene membranes by introducing acid functional groups to the polymeric film supported on a ceramic support. Various methods have been reported in literature15–17 for carboxylation of polystyrene. Styrene and maleic anhydride are copolymerized together and the anhydride group is hydrolyzed with NaOH to obtain acid functional groups on the membrane surface 15.…”

Section: Introductionmentioning

confidence: 99%

“…Styrene and maleic anhydride are copolymerized together and the anhydride group is hydrolyzed with NaOH to obtain acid functional groups on the membrane surface 15. Polystyrene was also directly metallated using 1 : 1 mixture of butyllithium and potassium‐ t ‐butoxide in cyclohexane/hexane mixture 16. The metallated polymer on reaction with solid carbon dioxide was carboxylated and further protonated by immersing in HCl solution.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of charged ultrafiltration poly(styrene‐ co‐divinyl benzene) composite membrane

Sachdeva

Kumar

2008

J of Applied Polymer Sci

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A ceramic supported crosslinked polystyrene composite membrane has been prepared from its monomers using a dual initiator system. The nonionic hydrophobic membrane so prepared has been chemically modified by a low temperature (508C), single step reaction with chloroacetic acid. The carboxylated membrane has acid functional groups on its surface making it negatively charged and highly hydrophilic in nature. The membranes (unmodified and carboxylated) have been used for the separation of hazardous chromium (VI) salt solution where observed and intrinsic rejection has been studied as a function of pressure and concentration of the feed solution. The intrinsic rejection has been determined by calculating the concentration at the membrane surface (C m ) using SpeiglerKedam model and osmotic pressure model. The observed rejection for the chemically modified membrane decreases with increasing pressure but the intrinsic rejection is found to be more than 80% for all concentrations in the range of study. The experimental results have been fitted using Space-Charge model to obtain the membrane wall potential and the membrane surface concentration which are difficult to measure directly. The transport through the membrane capillaries has been described by the two dimensional model using Nernst-Planck equation for ion transport, Navier-Stokes equation and Poisson-Boltzmann equation for the radial distribution of potential. We have then presented a semianalytical series solution to the highly nonlinear Poisson-Boltzmann equation to reduce the computational time required to solve the set of coupled differential equations. The effective wall potential of the carboxylated membrane was found to be 228.07 mV.

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