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Functional Monomers (functional + monomer)
Selected AbstractsAtom Transfer Radical Polymerization of Glycidyl Methacrylate: A Functional MonomerMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2004Pedro Francisco Cańamero Abstract Summary: A detailed investigation of the polymerization of glycidyl methacrylate (GMA), an epoxy-functional monomer, by atom transfer radical polymerization (ATRP) was performed. Homopolymers were prepared at relatively low temperatures using ethyl 2-bromoisobutyrate (EBrIB) as the initiator and copper halide (CuX) with N,N,N,,N,,N,-pentamethyldiethylenetriamine (PMDETA) as the catalyst system. The high polymerization rate in the bulk did not permit polymerization control. However, homopolymerization in solution enabled us to explore the effects of different experimental parameters, such as temperature, solvent (toluene vs. diphenyl ether) and initiator concentration, on the controllability of the ATRP process. SEC analysis of the homopolymers synthesized confirmed the importance of solvent character on molecular weight control, the lowest polydispersity indices () and the highest efficiencies being found when the polymerizations were performed in diphenyl ether in combination with a mixed halide technique. A novel poly(glycidyl methacrylate)- block -poly(butyl acrylate) (PGMA- b -PBA) diblock copolymer was prepared through ATRP using PGMA-Cl as a macro-initiator. This chain growth experiment demonstrated a good living character under the conditions employed, while simultaneously indicating a facile synthetic route for this type of functional block copolymer. In addition, the isotacticity parameter for the PGMAs obtained was estimated using 1H NMR analysis which gave a value of ,GMA,=,0.26 in agreement with that estimated in conventional radical polymerization. SEC chromatograms of PGMA-Cl macroinitiator and PGMA- b -PBA diblock copolymer. [source] Synthesis and Characterization of , -Cyclodextrin Based Functional Monomers and its Copolymers with N -isopropylacrylamideMACROMOLECULAR BIOSCIENCE, Issue 12 2003Yu-Yang Liu Abstract Two novel monovinyl , -cyclodextrin (, -CD) monomers are synthesized. Their chemical compositions are characterized by means of element analysis, NMR and FT-IR spectroscopy. The results show that the synthesis techniques used are convenient and efficient. Using N -isopropylacrylamide as a comonomer, two novel linear copolymers can also be synthesized. Synthesis route of monovinyl , -CD monomers. [source] A Biomimetic Potentiometric Sensor Using Molecularly Imprinted Polymer for the Cetirizine Assay in Tablets and Biological FluidsELECTROANALYSIS, Issue 18 2008Mehran Javanbakht Abstract Despite the increasing number of applications of molecularly imprinted polymers (MIPs) in analytical chemistry, the construction of a biomimetic potentiometric sensor remains still challenging. In this work, a biomimetic potentiometric sensor, based on a non-covalent imprinted polymer was fabricated for the recognition and determination of cetirizine. The MIP was synthesized by precipitation polymerization, using cetirizine dihydrochloride as a template molecule, methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross linking agent. The sensor showed high selectivity and a sensitive response to the template in aqueous system. The MIP-modified electrode exhibited Nernstian response (28.0±0.9 mV/decade) in a wide concentration range of 1.0×10,6 to 1.0×10,2 M with a lower detection limit of 7.0×10,7 M. The electrode has response time of ca. 20,s, high performance, high sensitivity, and good long term stability (more than 5,months). The method was satisfactory and used to the cetirizine assay in tablets and biological fluids. [source] Determination of Diclofenac in Urine Samples by Molecularly-Imprinted Solid-Phase Extraction and Adsorptive Differential Pulse VoltammetryELECTROANALYSIS, Issue 15 2007Laura Fernández-Llano Abstract A molecularly imprinted polymer for diclofenac (DCF) was prepared by thermal polymerization over silica beads using 2-(dimethylamino)ethyl-methacrylate as functional monomer. After silica elimination by HF treatment, the polymer was applied to the selective solid-phase extraction of the drug from urine followed by its quantification by adsorptive differential pulse voltammetry. Results indicate that the drug could be selectively extracted from the sample and quantified at clinically relevant concentrations (,g/mL). [source] (S)-Ibuprofen-imprinted polymers incorporating ,-methacryloxypropyl-trimethoxysilane for CEC separation of ibuprofen enantiomersELECTROPHORESIS, Issue 21 2006Qi-Liang Deng Abstract In this report, a novel preparation method of molecularly imprinted polymers (MIPs) for CEC was developed. Molecularly imprinted monolithic columns for (S)-ibuprofen were prepared and evaluated, in which charged entities responsible for establishing EOF have been derived from ,-methacryloxypropyltrimethoxysilane (,-MAPS), which was hydrolyzed following copolymerization with 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate,(EDMA). The EOF and molecular recognition of the stationary phase were investigated in aqueous and nonaqueous media, respectively. The experimental results indicated that the material showed a reasonably stable EOF and the prepared separation materials were capable of separating racemic ibuprofen, a task that could not be accomplished by MIPs prepared in parallel, using methacrylic acid (MAA) as a functional monomer. The efficiency at pH,3.2 for the first-eluted enantiomer and the last-eluted enantiomer (the imprinted analyte) were 128,700 and 2100,plates/m, respectively. [source] Preparation and Characteristics of Esculin-Imprinted PolymersHELVETICA CHIMICA ACTA, Issue 6 2007Guo-Song Wang Abstract Four molecularly imprinted polymers (MIPs) were prepared in MeOH with esculin (=6,7-dihydroxycoumarin 6-(, - D -glucopyranoside)=6-(, - D -glucopyranosyloxy)-7-hydroxy-2H -1-benzopyran-2-one) as the imprinted molecule, methacrylic acid (=2-methylprop-2-enoic acid; MAA), acrylamide (=prop-2-enamide; AM), 4-vinylpyridine (=4-ethenylpyridine; 4-VP), or 2-vinylpyridine (=2-ethenylpyridine; 2-VP) as the functional monomer, respectively, as well as ethylene glycol dimethacrylate (=2-methylprop-2-enoic acid ethane-1,2-diyl ester; EGDMA) as the cross-linking agent. The interaction between the template and the functional monomers was investigated by fluorescence and UV spectrophotometry, respectively, which revealed the presence of esculin/monomer complexes in the stoichiometric ratio 1,:,2 in the pre-polymerization mixture. The resultant polymers were studied in equilibrium binding experiments to evaluate the recognition ability and the binding capacity towards esculin. The results showed that MIP1, prepared with MAA as the functional monomer, exhibited advantageous characteristics of high binding capacity, optimal imprinting effect, and good selectivity towards esculin. The Scatchard analysis indicated that there are two types of binding sites in MIP1, and its binding parameters including the apparent maximum numbers of binding sites and the dissociation constants were calculated. Finally, by packing an SPE column (SPE=solid-phase extraction) with MIP1, the esculin was separated and enriched successfully by this sorbent from samples of Cortex fraxini, and the average recovery was up to 74.7%. [source] Molecular imprinted solid-phase extraction of huperzine A from Huperzia SerrataJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2009Guosong Wang Abstract On the basis of the non-covalent interaction between template and monomer, porous molecularly imprinted polymers (MIPs) were synthesized by a thermal-initiated polymerization method using huperzine A as template, acrylamide, or methacrylic acid as function monomer, ethylene glycol dimethacrylate as cross-linking agent. The interaction between template and functional monomers was studied by UV spectrophotometry, which showed a formation of huperzine A-monomer complexes with stoichiometric ratio of 1 : 2 in the pre-polymerized systems. The resultant MIP particles were tested in the equilibrium binding experiment to analyze their adsorption ability to huperzine A, and were characterized by Fourier Transform Infrared (FTIR) study. The recognition properties of MIP were estimated in solid-phase extraction by selecting four compounds (isolated from the Chinese herb Huperzia serrata) as substrates, and were compared with and prior to those of the NIP. High affinity and adsorption of MIP1 which was prepared in chloroform with huperzine A as imprinted molecule, and acrylamide (AM) as functional monomer, made an attractive application of MIP1 in separation processes. In final, using MIP1 solid-phase extraction micro-column, huperzine A was enriched and separated from the real extraction sample of Huperzia serrata. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Benzoxazine containing polyester thermosets with improved adhesion and flexibilityJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2010Alev Tuzun Abstract High molecular weight polyesters containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich and subsequent ring closure reactions of bisphenol-A, paraformaldehyde, and 5-amino-1-pentanol. Polycondensation of the resulting benzoxazine and pyromellitic dianhydride or 4-4,-(hexafluoroisopropylidene) diphatalic anhydride with or without dibutyltin laurate yielded the corresponding polyesters with the molecular weights between 5800 and 7000 Da. The structures of the precursor diol monomer and the resulting polyesters are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry. Flexible films of the polyesters were obtained by solvent casting on tin plates and crosslinked by heating in the absence of any catalyst. The cured films exhibited high flexibility and adhesion on the tin plates as determined by ASTM and DIN tests. Thermal properties of the cured polymers were also investigated by thermogravimetric analysis (TGA). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4279,4284, 2010 [source] Cupric ion enhanced molecular imprinting of bovine serum albumin in hydrogelJOURNAL OF SEPARATION SCIENCE, JSS, Issue 19 2009Sheng-Hua Li Abstract A novel molecularly imprinted hydrogel for bovine serum albumin (BSA) was prepared using cupric ion as the bridge between the template BSA and the functional monomer 4-vinylpyridine. N-Isopropylacrylamide (NIPA) was used as an assistant monomer to provide the stimuli-responsibility of the polymer. The adsorption conditions of BSA on the BSA-Cu(II)-imprinted hydrogel were optimized considering the influences of pH, temperature, and salt concentration. The proteins bound on the imprinted hydrogel can be easily recovered under mild conditions by using 10 mmol/L ethylene diamine tetraacetic acid (EDTA) (pH 7.0) containing 150 mmol/L NaCl as the eluting solution. The imprinting effect and adsorption capacity of the polymer were found to be significantly improved compared to the hydrogel prepared in the absence of cupric ion. The results demonstrated the advantages of using a template-metal ion-monomer coordination system to strengthen the interaction between the protein and monomer. The effects of different metals ions including Zn(II), Ni(II), Co(II), Cd(II), and Al(III) on the recognition ability of the BSA-Cu(II)-imprinted hydrogel were also investigated. The polymer showed high selectivity toward both the template protein and the cupric ion. [source] Selective enrichment of trace copper(II) from biological and natural water samples by SPE using ion-imprinted polymerJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6-7 2008Yunhui Zhai Abstract A novel Cu(II)-imprinted polymer sorbent was prepared by an ion-imprinted polymer (IIP) technique using (2Z)- N,N,-bis(2-aminoethylic)but-2-enediamide as the functional monomer and pentaerythritol triacylate as a crosslinker. IR, XPS, and elemental analysis techniques were used to confirm the obtained product. Subsequently, when this polymer was used as sorbent in SPE, it exhibited excellent selectivity for template ion from an aqueous solution. Quantitative extraction of Cu(II) was achieved in the pH range of 4,7. The time needed to extract each sample was less than 30 min by the batch method. The distribution ratio (D) values of IIP for Cu(II) were greatly larger than that for other ions. At optimal pH value, the maximum extraction capacity of IIP and nonimprinted polymer (NIP) was found to be 29.8 and 7.0 mg/g, respectively. The adsorption behavior of Cu(II) on the sorbents could be described by Langmuir adsorption isotherm equation. The feasible flow rate of Cu(II)-containing solution for quantitative extraction onto the column packed with IIP was 1,4 mL/min, whereas for elution it was less than 1 mL/min. The developed method was successfully applied to the separation and enrichment of trace Cu(II) in biological and natural water samples with satisfactory results. [source] Preparation and characterization of C16 monolithic columns for capillary electrochromatographyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 3 2005Kai Zhang Abstract A series of methacrylamide-based C16 monolithic columns were prepared and characterized to determine how their porous structural properties and chromatographic behavior are affected by the percentages of functional monomer, base monomer, and cross-linker in the polymerization solution. Baseline separation of 6 neutral compounds can be readily obtained in an optimized column. Furthermore, the effects of organic additive in the mobile phase, operating voltages, and temperature on retention behaviors and separation efficiencies were also studied. The separation mechanism is also discussed. High column efficiency and good reproducibility indicate that the monolithic columns hold considerable promise. [source] Disaggregation of high-molecular weight species during downstream processing to recover functional monomerBIOTECHNOLOGY PROGRESS, Issue 3 2010Xuankuo Xu Abstract The use of chaotropic agents to recover functional monomeric material was investigated for the downstream purification of an Fc-fusion protein containing high levels of high-molecular weight (HMW) species. In batch studies, chaotropic agents irreversibly disaggregated a majority of the aggregated protein. An integrated processing mode, termed as on-column disaggregation, was developed in which the protein was captured on Protein A chromatography and then a chaotropic agent was used to simultaneously elute the bound protein and disaggregate the HMW species. On-column disaggregation process resulted in protein recoveries of >95% and aggregation reduction of ,50%. Analytical results are presented showing that the recovered monomeric material was comparable to the reference protein in biochemical, biophysical, and pharmacokinetic properties. The kinetic and molecular mechanisms governing protein aggregation and disaggregation will also be elucidated. For the Fc-fusion protein studied here, incorporation of the disaggregation strategy in both batch and on-column modes led to an increase of >10% in overall downstream yield. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Solid-Phase Extraction of Metoprolol onto (Methacrylic acid- ethylene glycol dimethacrylate)-based Molecularly Imprinted Polymer and Its Spectrophotometric DeterminationCHINESE JOURNAL OF CHEMISTRY, Issue 4 2010Mohammad Saber Tehrani Abstract A new adsorbent for molecularly imprinted solid phase extraction (MISPE) of metoprolol was synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linking agent causing a non-covalent, bulk, thermal radical-polymerization. Control polymer (non-imprinted polymer) was prepared under well defined conditions without the use of metoprolol. The synthesized polymers were characterized by IR spectroscopy, X-ray diffraction and thermal analysis techniques. This polymer was used for the rapid extraction and preconcentration of metoprolol from real samples prior to spectrophotometric determination. Extraction efficiency and the influence of flow rates of sample and stripping solutions, pH, type of eluent for elution of metoprolol from polymer, break through volume and limit of detection were studied. The detection limit of the proposed method is 0.4 ng·mL,1. The method was applied successfully to the recovery and determination of metoprolol in tablets, human urine and plasma samples. [source] Sensitive Biomimetic Sensor Based on Molecular Imprinting at Functionalized Indium Tin Oxide ElectrodesELECTROANALYSIS, Issue 16 2007Na Gao Abstract We initially report an electrochemical sensing platform based on molecularly imprinted polymers (MIPs) at functionalized Indium Tin Oxide Electrodes (ITO). In this research, aminopropyl-derivatized organosilane aminopropyltriethoxysilane (APTES), which plays the role of functional monomers for template recognition, was firstly self-assembled on an ITO electrode and then dopamine-imprinted sol was spin-coated on the modified surface. APTES which can interact with template dopamine (DA) through hydrogen bonds brought more binding sites located closely to the surface of the ITO electrode, thus made the prepared sensor more sensitive for DA detection. Potential scanning is presented to extract DA from the modified film, thus DA can rapidly and completely leach out. The affinity and selectivity of the resulting biomimetic sensor were characterized using cyclic voltammetry (CV). It exhibited an increased affinity for DA over that of structurally related molecules, the anodic current for DA oxidation depended on the concentration of DA in the linear range from 2×10,6 M to 0.8×10,3 M with a correlation coefficient of 0.9927. In contrast, DA-templated film prepared under identical conditions on a bare ITO showed obviously lower response toward dopamine in solution. It should be noted that potential scanning is a very effective approach for DA extraction, and surface modification of the electrochemical transducer with functional monomers is responsible for the development of MIPs-based highly sensitive biomimetic sensor. [source] Preparation and characterization of a molecularly imprinted monolithic column for pressure-assisted CEC separation of nitroimidazole drugsELECTROPHORESIS, Issue 16 2010Sulan Liao Abstract A polymethacrylate-based molecularly imprinted monolithic column bearing mixed functional monomers, using non-covalent imprinting approach, was designed for the rapid separation of nitroimidazole compounds. The new monolithic column has been prepared via simple in situ polymerization of 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate and ethylene dimethacrylate, using (S)-ornidazole ((S)-ONZ) as template in a binary porogenic mixture consisting of toluene and dodecanol. The composition of the polymerization mixture was systematically altered and optimized by altering the amount of monomers as well as the composition of the porogenic solvent. The column performance was evaluated in pressure-assisted CEC mode. Separation conditions such as pH, voltage, amount of organic modifier and salt concentration were studied. The optimized monolithic column resulted in excellent separation of a group of structurally related nitroimidazole drugs within 10,min in isocratic elution condition. Column efficiencies of 99,000, 80,000, 103,000, 60,000 and 99,000,plates/m were obtained for metronidazole, secnidazole, ronidazole, tinidazole and dimetridazole, respectively. Parallel experiments were carried out using molecularly imprinted and non-imprinted capillary columns. The separation might be the result of combined effects including hydrophobic, hydrogen bonding and the imprinting cavities on the (S)-ONZ-imprinted monolithic column. [source] Preparation and Characteristics of Esculin-Imprinted PolymersHELVETICA CHIMICA ACTA, Issue 6 2007Guo-Song Wang Abstract Four molecularly imprinted polymers (MIPs) were prepared in MeOH with esculin (=6,7-dihydroxycoumarin 6-(, - D -glucopyranoside)=6-(, - D -glucopyranosyloxy)-7-hydroxy-2H -1-benzopyran-2-one) as the imprinted molecule, methacrylic acid (=2-methylprop-2-enoic acid; MAA), acrylamide (=prop-2-enamide; AM), 4-vinylpyridine (=4-ethenylpyridine; 4-VP), or 2-vinylpyridine (=2-ethenylpyridine; 2-VP) as the functional monomer, respectively, as well as ethylene glycol dimethacrylate (=2-methylprop-2-enoic acid ethane-1,2-diyl ester; EGDMA) as the cross-linking agent. The interaction between the template and the functional monomers was investigated by fluorescence and UV spectrophotometry, respectively, which revealed the presence of esculin/monomer complexes in the stoichiometric ratio 1,:,2 in the pre-polymerization mixture. The resultant polymers were studied in equilibrium binding experiments to evaluate the recognition ability and the binding capacity towards esculin. The results showed that MIP1, prepared with MAA as the functional monomer, exhibited advantageous characteristics of high binding capacity, optimal imprinting effect, and good selectivity towards esculin. The Scatchard analysis indicated that there are two types of binding sites in MIP1, and its binding parameters including the apparent maximum numbers of binding sites and the dissociation constants were calculated. Finally, by packing an SPE column (SPE=solid-phase extraction) with MIP1, the esculin was separated and enriched successfully by this sorbent from samples of Cortex fraxini, and the average recovery was up to 74.7%. [source] Molecular imprinted solid-phase extraction of huperzine A from Huperzia SerrataJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2009Guosong Wang Abstract On the basis of the non-covalent interaction between template and monomer, porous molecularly imprinted polymers (MIPs) were synthesized by a thermal-initiated polymerization method using huperzine A as template, acrylamide, or methacrylic acid as function monomer, ethylene glycol dimethacrylate as cross-linking agent. The interaction between template and functional monomers was studied by UV spectrophotometry, which showed a formation of huperzine A-monomer complexes with stoichiometric ratio of 1 : 2 in the pre-polymerized systems. The resultant MIP particles were tested in the equilibrium binding experiment to analyze their adsorption ability to huperzine A, and were characterized by Fourier Transform Infrared (FTIR) study. The recognition properties of MIP were estimated in solid-phase extraction by selecting four compounds (isolated from the Chinese herb Huperzia serrata) as substrates, and were compared with and prior to those of the NIP. High affinity and adsorption of MIP1 which was prepared in chloroform with huperzine A as imprinted molecule, and acrylamide (AM) as functional monomer, made an attractive application of MIP1 in separation processes. In final, using MIP1 solid-phase extraction micro-column, huperzine A was enriched and separated from the real extraction sample of Huperzia serrata. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Non-covalent molecular imprinting with emphasis on its application in separation and drug development,JOURNAL OF MOLECULAR RECOGNITION, Issue 4 2006Huiqi Zhang Abstract The molecular imprinting technique can be defined as the formation of specific nano-sized cavities by means of template-directed synthesis. The resulting molecularly imprinted polymers (MIPs), which often have an affinity and a selectivity approaching those of antibody-antigen systems, have thus been coined "artificial antibodies." MIPs are characterized by their high specificity, ease of preparation, and their thermal and chemical stability. They have been widely studied in connection with many potential applications, including their use for separation and isolation purposes, as antibody mimics (biomimetic assays and sensors), as enzyme mimics, in organic synthesis, and in drug delivery. The non-covalent imprinting approach, developed mainly in Lund, has proven to be more versatile than the alternative covalent approach because of its preparation being less complicated and of the broad selection of functional monomers and possible target molecules that are available. The paper presents a review of studies of this versatile technique in the areas of separation and drug development, with emphasis being placed on work carried out in our laboratory. Copyright © 2006 John Wiley & Sons, Ltd. [source] Uptake of nicotine from suspension culture of Nicotiana tabacum by molecularly imprinted polymersJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 5 2010Mohamed Salaheldin A. Abdelkader Abstract Objectives The aim was to use molecularly imprinted polymers (MIPs) for the selective recovery of nicotine in plant cell cultures. MIPs can selectively uptake nicotine from suspension cultures of N. tabacum, and therefore may be useful for improving levels of secondary metabolites in plant cell cultures. Methods Suspension cultures of N. tabacum were initiated from callus and maintained in liquid Murashige and Skoog (MS) media containing 3% w/v sucrose, 0.1 mg/l ,-naphthaleneacetic acid acid (NAA) and 0.25 mg/l kinetin. Tween 80 at 1% was used for permeabilisation of cell cultures. Pre-weighed XAD-2 and two types of synthesized polymers, MIPs (A and B with one and two functional monomers, respectively) and corresponding non-imprinted polymers (NIPs), A and B, were introduced aseptically into the permeabilised suspension cultures of N. tabacum, the nicotine contents of polymers were determined by gas chromatography and the adsorption yield of polymers were determined. Key findings Cell cultures of N. tabacum accumulated nicotine alkaloid intracellularly in varying levels, 6.8,14.9 mg/l fresh weight. MIPs were able to uptake 50,70% of released nicotine in suspension cultures of N. tabacum, whereas XAD-2 recovered only 30,40%. The total levels of accumulated nicotine were enhanced up to 20 mg/l by simultaneous use of Tween 80 and MIPs. Conclusions The findings indicate the potential use of MIPs to uptake nicotine from suspension cultures of N. tabacum, and increase productivity of secondary metabolites in plant cell cultures. [source] Kinetic investigation of the RAFT polymerization of p -acetoxystyreneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 12 2010Solčne I. Cauët Abstract The kinetics of the RAFT polymerization of p -acetoxystyrene using a trithiocarbonate chain transfer agent, S -1-dodecyl- S,-(,,,,-dimethyl-,,-acetic acid)trithiocarbonate, DDMAT, was investigated. Parameters including temperature, percentage initiator, concentration, monomer-to-chain transfer agent ratio, and solvent were varied and their impact on the rate of polymerization and quality of the final polymer examined. Linear kinetic plots, linear increase of Mn with monomer conversion, and low final molecular weight dispersities were used as criteria for the selection of optimized polymerization conditions, which included a temperature of 70 or 80 °C with 10 mol % AIBN initiator in bulk for low conversions or in 1,4-dioxane at a monomer-to-solvent volume ratio of 1:1 for higher conversions This study opens the way for the use of DDMAT as a chain transfer agent for RAFT polymerization to incorporate p -acetoxystyrene together with other functional monomers into well-defined copolymers, block copolymers, and nanostructures. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2517,2524, 2010 [source] Electrochemical synthesis of PEDOT derivatives bearing imidazolium-ionic liquid moietiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 12 2009Markus Döbbelin Abstract Novel poly(3,4-ethylenedioxythiophene) (PEDOT) polymers bearing imidazolium-ionic liquid moieties were synthesized by electrochemical polymerizations. For this purpose, new functional monomers were synthesized having an 3,4-ethylenedioxythiophene (EDOT) unit and an imidazolium-ionic liquid with different anions such as tetrafluoroborate (BF), bis(trifluoromethane)sulfonimide ((CF3SO2)2N,), and hexafluorophosphate (PF). Next, polymer films were obtained by electrochemical synthesis in dicholoromethane solutions. Obtained polymers were characterized, revealing the characteristics of PEDOT in terms of electrochemical and spectroelectrochemical properties, FTIR, 1H NMR, and AFM microscopy. Interestingly, the hydrophobic character of electropolymerized films could be modified depending on the anion type. The hydrophobicity followed the trend PF > (CF3SO2)2N, > BF > pure PEDOT as determined by water contact angle measurements. Furthermore, the polymers could be dissolved in a range of polar organic solvents such as dimethylformamide, propylene carbonate, and dimethyl sulfoxide making these polymers interesting candidates for wet processing methods. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3010,3021, 2009 [source] Living cationic polymerization of amide-functional vinyl ethers: Specific properties of SnCl4 -based initiating systemJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2008Motomasa Yonezumi Abstract Living cationic copolymerization of amide-functional vinyl ethers with isobutyl vinyl ether (IBVE) was achieved using SnCl4 in the presence of ethyl acetate at 0 °C: the number,average molecular weight of the obtained polymers increased in direct proportion to the monomer conversion with relatively low polydispersity, and the amide-functional monomer units were introduced almost quantitatively. To optimize the reaction conditions, cationic polymerization of IBVE in the presence of amide compounds, as a model reaction, was also examined using various Lewis acids in dichloromethane. The combination of SnCl4 and ethyl acetate induced living cationic polymerization of IBVE at 0 °C when an amide compound, whose nitrogen is adjacent to a phenyl group, was used. The versatile performance of SnCl4 especially for achieving living cationic polymerization of various polar functional monomers was demonstrated in this study as well as in our previous studies. Thus, the specific properties of the SnCl4 initiating system are discussed by comparing with the EtxAlCl3,x systems from viewpoints of hard and soft acids and bases principle and computational chemistry. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6129,6141, 2008 [source] Selective polymerization of functional monomers with Novozym 435JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2007Martijn A. J. Veld Abstract Two novel monomers, ambrettolide epoxide and isopropyl aleuriteate, encompassing functional groups, were obtained in a single step from commercially available materials. Novozym 435 catalyzed ring opening polymerization of ambrettolide epoxide furnished a polymer of Mn = 9.7 kg/mol and PDI = 1.9 while the epoxide groups remained unaffected during the polymerization. Selective polymerization of the primary hydroxyl groups of isopropyl aleuriteate using Novozym 435 was feasible and a polymer with moderate molecular weight (Mn = 5.6 kg/mol, PDI = 3.2) was isolated in moderate yield (43%). Subsequently, copolymerization of isopropyl aleuriteate with ,-CL in different ratios was performed, resulting in soluble, hydroxy functional polymers with good molecular weights (Mn = 10.4,27.2 kg/mol) in good yield (71,78%). The secondary hydroxy groups in the polymer reacted easily with hexyl isocyanate, showing the potential of isopropyl aleuriteate as a comonomer for the synthesis of functional polyesters. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5968,5978, 2007 [source] Synthesis of AB-type block copolymers containing benzoxazole and anthracene groups by ATRP and fluorescent propertyJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2007Jian-Mei Lu Abstract Two functional monomers, methacrylic acid 4-(2-benzoxazol)-benzyl ester (MABE) containing the benzoxazole group and 4-(2-(9-anthryl))-vinyl-styrene (AVS) containing the anthracene group were synthesized by rational design. The MABE was polymerized via atom transfer radical polymerization (ATRP) using ethyl 2-bromoisobutyrate (EBIB) as initiator in CuBr/N,N,N,,N,,N,-pentamethyldiethylenetriamine (PMDETA) catalyst system; block copolymers poly(MABE- b -AVS) was obtained, which was conducted by using poly(MABE) as macro-initiator, AVS as the second monomer, and CuBr/PMDETA as catalyst. The constitute of two monomers in block copolymers poly(MABE- b -AVS) by ATRP could be adjusted, that is the constitute of the benzoxazole group and the anthracene group could be controlled in AB-type block copolymers. Moreover, the fluorescent properties of homopolymers poly(MABE) and block copolymers poly(MABE- b -AVS) were discussed herein. With the excitation at ,ex = 330 nm, the fluorescent emission spectrum of poly(MABE) solution showed emission at 375 nm corresponding to the benzoxazole-based part; with the same excitation, the fluorescent emission spectrum of poly(MABE- b -AVS) solution showed a broad peek at 330,600 nm when the monomer AVS to the total monomers mole ratio was 0.31, and the fluorescent emission spectrum of poly(MABE- b -AVS) in film state only showed one peak at 525 nm corresponding to the anthracene-based unit that indicated a complete energy transfer from the benzoxazole group to the anthracene group. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3894,3901, 2007 [source] Molecular imprinting of AMP by an ionic-noncovalent dual approachJOURNAL OF SEPARATION SCIENCE, JSS, Issue 19 2009Florent Breton Abstract In order to mimic recognition properties of adenylate kinase, molecularly imprinted polymers (MIPs) were prepared for adenosine 5,-monophosphate (AMP), a substrate of the enzyme. Different functional monomers interacting with the phosphate moiety were tested, and the MIP giving the best specific binding of AMP was composed with one equivalent of 2-(dimethylamino)ethyl methacrylate and ten equivalents of acrylamide compared to AMP. Packed into solid phase cartridge, this polymer showed similar characteristics than the enzyme, since it was specific for AMP toward other nucleotides. [source] Preparation and HPLC applications of rigid macroporous organic polymer monolithsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10-11 2004Frantisek Svec Abstract Rigid porous polymer monoliths are a new class of materials that emerged in the early 1990s. These monolithic materials are typically prepared using a simple molding process carried out within the confines of a closed mold. For example, polymerization of a mixture comprising monomers, free-radical initiator, and porogenic solvent affords macroporous materials with large through-pores that enable applications in a rapid flow-through mode. The versatility of the preparation technique is demonstrated by its use with hydrophobic, hydrophilic, ionizable, and zwitterionic monomers. Several system variables can be used to control the porous properties of the monolith over a broad range and to mediate the hydrodynamic properties of the monolithic devices. A variety of methods such as direct copolymerization of functional monomers, chemical modification of reactive groups, and grafting of pore surface with selected polymer chains is available for the control of surface chemistry. Since all the mobile phase must flow through the monolith, the convection considerably accelerates mass transport within the molded material, and the monolithic devices perform well, even at very high flow rates. The applications of polymeric monolithic materials are demonstrated mostly on the separations in the HPLC mode, although CEC, gas chromatography, enzyme immobilization, molecular recognition, advanced detection systems, and microfluidic devices are also mentioned. [source] Highly Functional Poly(meth)acrylates via Cascade ReactionMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 2 2009Dragos Popescu Abstract A new route to the synthesis of highly functional and reactive polymethacrylates via cascade reactions comprising enzymatically and chemically catalyzed steps is presented. Transacylation of methyl acrylate and methyl methacrylate as substrates with different functional alcohols in the presence of Novozyme 435 leads to a mixture of functional monomers, which in a subsequent step was copolymerized via free radical polymerization, resulting in polymethacrylates with predefined functionalities. Hydrophilic, hydrophobic, as well as ionic methacrylate repeating units were assembled in a copolymer and adjusted for surface coatings. [source] Multi-Component Kinetic Modeling for Controlling Local Compositions in Thermosensitive PolymersMACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2006Todd Hoare Abstract Summary: An explicit terminal copolymerization kinetic model accounting for the copolymerization of up to four different comonomers is developed and applied to model the conversion profiles and local compositional gradients in functionalized PNIPAM-based polymer and hydrogel systems. The kinetics of the functional comonomer(s) have a large influence on both the mole fraction and chain distribution of functional groups in polymers. Strategies are developed to synthesize polymers with uniform compositions by applying semi-batch techniques or via copolymerization of multiple monomers with the same target functionality but with divergent reactivities relative to NIPAM. Synthetic protocols are also designed to maximize the compositional uniformity and randomness of ampholytic polymers. Instantaneous mole fractions of monomers in polymers as a function of the overall monomer conversion for the copolymerizations of NIPAM, MBA, and two functional monomers: MMA and acrylamide. [source] Networks for recognition of biomolecules: molecular imprinting and micropatterning poly(ethylene glycol)- Containing films,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 10-12 2002Mark E. Byrne Abstract Engineering the molecular design of biomaterials by controlling recognition and specificity is the first step in coordinating and duplicating complex biological and physiological processes. Studies of protein binding domains reveal molecular architectures with specific chemical moieties that provide a framework for selective recognition of target biomolecules in aqueous environment. By matching functionality and positioning of chemical residues, we have been successful in designing biomimetic polymer networks that specifically bind biomolecules in aqueous environments. Our work addresses the preparation, behavior, and dynamics of the three-dimensional structure of biomimetic polymers for selective recognition via non-covalent complexation. In particular, the synthesis and characterization of recognitive gels for the macromolecular recognition of D -glucose is highlighted. Novel copolymer networks containing poly(ethylene glycol) (PEG) and functional monomers such as acrylic acid, 2-hydroxyethyl methacrylate, and acrylamide were synthesized in dimethyl sulfoxide (polar, aprotic solvent) and water (polar, protic solvent) via UV-free radical polymerization. Polymers were characterized by single and competitive equilibrium and kinetic binding studies, single and competitive fluorescent and confocal microscopy studies, dynamic network swelling studies, and ATR-FTIR. Results qualitatively and quantitatively demonstrate effective glucose-binding polymers in aqueous solvent. Owing to the presence of template, the imprinting process resulted in a more macroporous structure as exhibited by dynamic swelling experiments and confocal microscopy. Polymerization kinetic studies suggest that the template molecule has more than a dilution effect on the polymerization, and the effect of the template is related strongly to the rate of propagation. In addition, PEG containing networks were micropatterned to fabricate microstructures, which would be the basis for micro-diagnostic and tissue engineering devices. Utilizing photolithography techniques, polymer micropatterns of a variety of shapes and dimensions have been created on polymer and silicon substrates using UV free-radical polymerizations with strict spatial control. Micropatterns were characterized using optical microscopy, SEM, and profilometry. The processes and analytical techniques presented are applicable to other stimuli-sensitive and recognitive networks for biomolecules, in which hydrogen bonding, hydrophobic, or ionic contributions will direct recognition. Further developments are expected to have direct impact on applications such as analyte controlled and modulated drug and protein delivery, drug and biological elimination, drug targeting, tissue engineering, and micro- or nano-devices. This work is supported by NSF Grant DGE-99-72770. Copyright © 2003 John Wiley & Sons, Ltd. [source] Synthesis of an Enzyme-like Imprinted Polymer with the Substrate as the Template, and Its Catalytic Properties under Aqueous ConditionsCHEMISTRY - A EUROPEAN JOURNAL, Issue 14 2004Zhiyong Cheng Dr. Abstract Transition state analogues (TSAs) have long been regarded as ideal templates for the preparation of catalytically active synthetic imprinted polymers. In the current work, however, a new type of molecularly imprinted polymer (MIP) was synthesized with the substrate (homovanillic acid, HVA) as the template and hemin introduced as the catalytic center, with the use of plural functional monomers to prepare the active sites. The MIP successfully mimicked natural peroxidase, suggesting that it may not be imperative to employ a TSA as the template when preparing enzyme-like imprinted polymers and that the imprinted polymer matrix provided an advantageous microenvironment around the catalytic center (hemin), essentially similar to that supplied by apo-proteins in natural enzymes. Significantly, by taking advantage of the special structure of hemin and multiple-site interactions provided by several functional monomers, the intrinsic difficulties for MIPs in recognizing template molecules in polar solutions were overcome. The newly developed polymer showed considerable recognizing ability toward HVA, catalytic activity, substrate specificity and also stability, which are the merits lacked by the natural peroxidase. Meanwhile, the ease of recovery and reuse the MIP implies the potential for industrial application. [source] | ||||||||||||||||