Salt Monomers Research Articles

Preparation of aliphatic polypyromellitimide particles by polycondensation of nylon-salt-type monomers derived from aliphatic diamines with diethyl pyromellitate in ethylene glycol

Polycondensations of nylon-salt-type monomers composed with diethyl pyromellitate and aliphatic diamines with various methylene lengths were performed at 130 °C in ethylene glycol to afford flower-like particles. Before the polycondensation, the salt monomer solution was homogenous. As the polycondensation proceeded, the solution became turbid and polyimide particles grew to around 15 µm in 8 h. Further polycondensation broke the particles into small pieces. The polyimide particles showed the distinctive odd-even effect of the methylene chain of diamine in both inherent viscosity and crystallinity. The polyimide particles using diamine with even-methylene length had higher crystallinity and lower inherent viscosity than those using diamine with odd-methylene length.

Functional Military Textile: Plasma-Induced Graft Polymerization of DADMAC for Antimicrobial Treatment on Nylon-Cotton Blend Fabric

In this study, diallyldimethylammonium chloride (DADMAC), a quaternary ammonium salt monomer, is graft polymerized on 50–50 Nylon-Cotton (NyCo) standard military fabric using atmospheric pressure glow discharge plasma to impart self-detoxification capability. Atmospheric pressure plasma is used to induce free radical chain polymerization of the DADMAC monomer to introduce a graft polymerized network on the fabric with durable antimicrobial properties. Pentaerythritol tetraacrylate (PETA) is used as a cross-linking agent to obtain a highly cross-linked, durable polymer network. The presence of polyDADMAC on the fabric surface is confirmed using acid dye staining, SEM, and TOF–SIMS. Antibacterial performance is investigated using standard AATCC Test Method 100 for both gram positive and gram negative bacteria. Results show 99.9 % reduction in the bacterial activities of Klebsiella pneumoniae and Staphylococcus aureus.

Synthesis and Characterization of Fluorescent Acrylamide Water Soluble Macromer

Fluorescent acrylamide water soluble macromer was synthesized from dimethylaminopropylmethacrylamide-9-(chloromethyl)anthracene quaternary ammonium salt monomer using an inverse emulsion polymerization method. It was initiated by benzoylperoxide and stabilized by a co-emulsifier system consisting of Span®80 and Tween®60 dispersed in a continuous phase of cyclohexane with HLB value of 6.42. The polymerization was done at 80°C for 4 hours. The obtained macromer exhibited similar functional groups, ultraviolet-visible absorption and fluorescent emission but different solubility when compared to the monomer. Further analyses by proton nuclear magnetic resonance spectroscopy and mass spectrometry revealed the chemical structure of the macromer as a dimer of the monomer containing carcon-carbon double bonds.

A Biliary HCO3 − Umbrella Constitutes A Protective Mechanism Against Bile Acid–Induced Injury in Human Cholangiocytes

Human cholangiocytes are continuously exposed to millimolar levels of hydrophobic bile salt monomers. We recently hypothesized that an apical biliary HCO3- umbrella might prevent the protonation of biliary glycine-conjugated bile salts and uncontrolled cell entry of the corresponding bile acids, and that defects in this biliary HCO3- umbrella might predispose to chronic cholangiopathies. Here, we tested in vitro whether human cholangiocyte integrity in the presence of millimolar bile salt monomers is dependent on (1) pH, (2) adequate expression of the key HCO3- exporter, anion exchanger 2 (AE2), and (3) an intact cholangiocyte glycocalyx. To address these questions, human immortalized cholangiocytes and cholangiocarcinoma cells were exposed to chenodeoxycholate and its glycine/taurine conjugates at different pH levels. Bile acid uptake was determined radiochemically. Cell viability and apoptosis were measured enzymatically. AE2 was knocked down by lentiviral short hairpin RNA. A cholangiocyte glycocalyx was identified by electron microscopy, was enzymatically desialylated, and sialylation was quantified by flow cytometry. We found that bile acid uptake and toxicity in human immortalized cholangiocytes and cholangiocarcinoma cell lines in vitro were pH and AE2 dependent, with the highest rates at low pH and when AE2 expression was defective. An apical glycocalyx was identified on cholangiocytes in vitro by electron microscopic techniques. Desialylation of this protective layer increased cholangiocellular vulnerability in a pH-dependent manner. A biliary HCO3- umbrella protects human cholangiocytes against damage by bile acid monomers. An intact glycocalyx and adequate AE2 expression are crucial in this process. Defects of the biliary HCO3- umbrella may lead to the development of chronic cholangiopathies.

Hydrogels as template nanoreactors for silver nanoparticles formation and their antimicrobial activities

Silver nanoparticles were synthesized and stabilized using the hydrogel template method. The synthesized hydrogels were composed of acrylamide and styrene sulfonic acid sodium salt monomers with different molar ratios. The copolymer with the highest ionic monomer content was interpenetrated with different chitosan concentrations. The main goal of this study was to evaluate the antimicrobial activity of the prepared hydrogels. The formation of silver nanoparticles within the swollen hydrogel was mainly due to an ion exchange process via the sulfonate and amino groups of the hydrogels. The surface morphology showed a uniform distribution of silver nanoparticles throughout the hydrogel structure. These nanoparticles had face-centered-cubic unit cell structure and dimensions less than 70 nm, as determined by X-ray and UV-visible spectroscopy, respectively. To investigate the antimicrobial activities of the prepared composites, their inhibitory effect was evaluated against bacteria, fungi, and yeasts. Increasing the ionic monomer and chitosan content enhanced both the swelling properties and the antimicrobial activities of these composites. The results clarified that the most sensitive strain was Bacillus subtilis.

Orthogonal chain length control in calix[5]arene-based AB-type supramolecular polymers

New AB-type supramolecular polymers have been prepared by acid-promoted self-assembly of an aminododecyloxy-calix[5]arene monomer precursor. The number-average degree of polymerization has been found to be dependent on the concentration of the salt monomer and on the nature of the counterion (i.e., chloride, picrate or hexafluorophosphate).Chain-length regulation experiments have been carried out, employing orthogonal chain stoppers capable of selectively interacting with a given moiety of the AB-type monomer/polymer. Competitive calix[5]arene ‘caps’ and n-butylammonium ion ‘plugs’ have been used to control the extent of self-assembly of the polymer, in turn interacting with the ammoniumdodecyloxy or with the cavity end-groups of the supramolecular calixarene assembly. These experiments, conveniently carried out at a 10mM concentration, can be easily followed by 1H NMR spectroscopy.

Study on antibacterial dental resin using tri-n-butyl(4-vinylbenzyl)phosphonium chloride

The antibacterial properties of a polymeric phosphonium salt were studied to determine its suitability as an additive to develop an antibacterial dental resin. The phosphonium salt monomer studied was tri-n-butyl(4-vinylbenzyl)phosphonium chloride (VP), and acrylic acid (AC) and methacryloyloxyethyl trimethyl ammonium chloride (MA) were used as controls. The antibacterial activity of these monomers and their corresponding polymers (PVP, PAC, and PMA) against Streptococcus mutans (S. mutans) was examined. When incubating S. mutans in a medium containing 10 μmol/mL for 24 hours, the antibacterial activity of PVP against S. mutans was high, while the antibacterial activity of PMA and VP was lower. AC, PAC and PMA exhibited the lowest antibacterial activity. The mechanical properties of the copolymers of methyl methacrylate, 2-hydroxyethyl methacrylate, and VP decreased as VP content increased, and were lower than those of poly(methyl methacrylate).

Novel anion exchange membranes based on polymerizable imidazolium salt for alkaline fuel cell applications

A new polymerizable imidazolium salt monomer, 1-(4-vinylbenzyl)-3-methyl-imidazolium chloride ([VBMI]Cl), has been readily synthesized by reaction of 4-vinylbenzyl chloride with 1-methylimidazole. Novel anion exchange membranes (AEMs) based on the copolymers of [VBMI]Cl and styrene have been prepared and characterized. Excellent thermostability of the membranes is observed through the thermo-gravimetric analysis (TGA) curves. Water uptake and ion exchange capacity (IEC) of the OH− form AEMs range from 26.1% to 61.9% and from 0.95 to 1.45 mmol g−1, respectively. This type of AEM displays significant ionic conductivities over the order of 10−2 S cm−1 in deionized water at room temperature, and the membranes are stable in 10 mol L−1NaOH solution at 60 °C for 120 h. For the H2/air single fuel cell at 30 °C with this novel AEM, the peak power density of 33 mW cm−2 is obtained at a current density of 59 mA cm−2.

Synthesis of antibacterial polymers from 2-dimethylamino ethyl methacrylate quaternized by dimethyl sulfate

An antibacterial quaternary ammonium acrylic monomer (1) was synthesized by quaternization of 2-dimethylamino ethyl methacrylate with dimethyl sulfate. This synthetic route to quaternary ammonium salt monomer proved to be of high yield and lower cost than that used to synthesize alkyl halide. The corresponding homopolymers (2) were then obtained by free radical polymerization using potassium persulfate as the initiator. The chemical structure was characterized by Fourier transform infrared and 1H-nuclear magnetic resonance, and molecular weights (MWs) were compared by the viscosity method. Factors influencing the synthesis of (1) and (2) were also investigated. Antibacterial activity was tested against Escherichia coli and Staphylococcus aureus using a minimum biocidal concentration test and the shaking flask method. Monomer (1) exhibited moderate antibacterial activity; however, the polymers had significantly stronger antibacterial activity than the monomer. Therefore, their potential for antibacterial application was established. Similar to other quaternary ammonium compounds, the antibacterial activity of the polymers depended on their MW, and this dependence varied with the type of testing microorganisms.

Synthesis of Highly Fluorescent and Soluble 1,2,4‐Linking Hyperbranched Poly(arylenevinylene) Featuring Intramolecular Energy Funneling

AbstractThe synthesis and optical properties of a highly soluble (>200 mg mL−1) and highly fluorescent (ΦF in film = 0.64) 1,2,4‐linking hyperbranched poly(arylenevinylene) (1,2,4‐hb‐PAV) prepared via Wittig reaction of A3 (biphenyl‐tricarbaldehyde) and B2 (phosphonium salt) monomers is reported. The molecular weight of 1,2,4‐hb‐PAV can be precisely controlled by the amount of the base (NaOCH3) used in the polymerization. The absorption and photoluminescence (PL) spectra of 1,2,4‐hb‐PAV shows distinct red‐shifts compared to conventional 1,3,5‐linking hyperbranched poly(arylenevinylene) (1,3,5‐hb‐PAV), attributed to the extended π‐conjugation along ortho‐ (1,2‐) and para‐ (1,4‐) links. The inherent energy gradient from the shorter branches to the longer conjugated stem in 1,2,4‐hb‐PAV enabled a characteristic energy funneling effect, which is absent in conventional hyperbranched polymer of 1,3,5‐hb‐PAV.

Acid hybrid catalysts from poly(styrenesulfonic acid) grafted onto ultra-large-pore SBA-15 silica using atom transfer radical polymerization

Poly(styrenesulfonic acid)-functionalized materials based on poly(styrenesulfonic acid sodium salt) incorporated via aqueous atom transfer radical polymerization (ATRP) initiated from the surface of large-pore mesoporous SBA-15 silica support have been synthesized. The inorganic–organic nature of these hybrid materials makes them particularly desirable for acid-catalyzed reactions that require extended and hydrophobic surface areas with a narrow pore diameter distribution in the mesoporous range. Acidic hybrid materials were prepared by grafting the ATRP-initiator (3-(chlorodimethylsilyl)propyl bromoisobutyrate) on the silica surface, subsequent polymerization of the styrenesulfonic acid sodium salt monomer, and final sodium ion exchange by acid activation. Conventional and ultra-large-pore SBA-15 silica supports with nominal (BJH) pore diameter ranging from 8 to 32 nm were used for the incorporation of different polymer loadings at different polymerization times. The silylation of ATRP-initiator-functionalized SBA-15 supports has allowed a better control of the ATRP within the mesoporous structure. The use of ultra-large-pore SBA-15 supports provides a remarkable increase of the porosity which allowed us to properly allocate the polymer. The hybrid poly(styrenesulfonic acid)-modified materials showed good catalytic activities in the esterification of oleic acid with n-butanol, particularly in terms of intrinsic activity per acid site.

Synthesis of porphyrin-incorporated polymers and their application for simultaneous detection of multimetal components by using spectrophotometry

For the purpose of detection of multimetal components in environment, alteration of the spectrophotometrical metal sensitivity of porphyrin was attempted. Two porphyrin-incorporated polymers were newly synthesized by the free radical copolymerization of protoporphyrin IX disodium salt and vinyl monomers, and their metal sensitivities were examined by measuring the difference absorption spectra. These porphyrin-incorporated polymers showed different metal sensitivities and their sensitivities were altered by change of pH. Three measuring reagents, which were different in the combination of the porphyrin-incorporated polymers and pH, were used for the simultaneous detection of multimetal components in metal ion mixtures. The difference spectra of these reagents showed the separate peaks corresponding to six metal ions, Bi(III), Co(II), Cu(II), Mn(II), Pb(II), and Zn(II). The spectra were acquired reproducibly by using standard normal variate (SNV) transformation. Furthermore, this method was applied to detect multimetal components in water samples such as tap water and industrial effluent.

Single-step rapid microwave-assisted synthesis of polyacrylamide–calcium phosphate nanocomposites in aqueous solution

Organic–inorganic polyacrylamide–calcium phosphate (PAM–CP) nanocomposites with calcium phosphate (CP) nanoparticles homogeneously dispersed in the polymer matrix have been successfully synthesized using calcium salt, phosphate and acrylamide monomer in aqueous solution by a single-step microwave-assisted method. When the experiment is conducted in a basic medium, the CP phase obtained consists of hexagonal hydroxyapatite (HAP) nanorods, and HAP nanorods are homogeneously dispersed in the polyacrylamide (PAM) matrix. While the preparation is in a weak acidic medium, the amorphous calcium phosphate (ACP) nanoparticles are formed and dispersed in the PAM matrix. The reported method has advantages of being simple, rapid, low-cost, and environmentally friendly. The products are characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TG).

Investigation of Polymer-bound PAGs: Synthesis, Characterization and Initial Structure/Property Relationships of Anion-bound Resists

A study of polymerization and some of the resulting properties of PAG-bound resist polymers based on a new triphenyl sulfonium fluoroalkyl sulfonate-containing methacrylate monomer is reported here. A low activation ester terpolymer containing this onium salt monomer was prepared and characterized. Our findings include the profound impact of residual monomer in the behavior of this material and the critical importance of polymer purification to remove unreacted ionic monomers in the preparation of polymer-bound PAGs. We have developed a polymer isolation process specifically tailored to remove unbound PAG so that the properties could be unambiguously investigated. And we report here the influence on properties of bound vs unbound PAG in this chemically amplified resist.

Hydrogels from 2-(dimethylamino)ethylacrylate with 2-acrylamido-2-methyl-1-propanesulfonic acid: synthesis, characterization, and water-sorption properties

A novel series of copolymer hydrogels of 2-(dimethylamino)ethylacrylate (DMAEA)/2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) were prepared by solution free radical polymerization at different feed monomer mol ratios. The monomer reactivity ratios were determined by Kelen–Tudos method. According to that, the monomer reactivity ratios for poly(DMAEA-co-AMPS) were r1 = 0.125 and r2 = 2.85, (r1 × r2 = 0.356). The effect of reaction parameters, including the concentration of cross-linking reagent N,N′-methylene-bis-acrylamide (MBA) and initiator ammonium persulfate (APS), the monomer concentration, pH, temperature, salt solutions, and solvent polarity on the water absorption have been also studied. The hydrogels achieved water-absorption values of 430 g of water/g of xerogel for the copolymer 1:2 richest in AMPS moiety. This copolymer is also very stable to the temperature effect. The optimum pH for the copolymers is 7. Aqueous solutions of the copolymers showed lower critical solution temperature behaviour (LCST). The phase transition temperatures of aqueous solutions of these copolymer increased with increasing of hydrophilic AMPS unit content in the copolymers. The glass transition temperature (Tg) of hydrogels showed a decrease by increasing of comonomer DMAEA content.

Viscosity and activation parameters of viscous flow of sodium cholate aqueous solution

Viscosity, density and electrical conductance of sodium cholate aqueous solution in dilute concentrations are reported. Concentration and temperature effects on the viscosity are discussed. Molar conductance of the salt at infinite dilution is obtained by fitting experimental conductivity in Quint–Viallard equation. Viscosity data is analyzed by Jones–Dole equation, and viscous B-coefficient and activation parameters are evaluated, which shows a strong effect of sodium cholate aggregation on viscosity flow. Our result shows that salt diffusion is characterized by molecular aggregation, and is enhanced progressively as the concentration of bile salt monomer increases.

Preparation and antibacterial activity of quaternary ammonium salt monomers

To prepare three quaternary ammonium salt (QAS) monomers, and to compare their antibacterial activities against four oral bacterial strains. Three antibacterial monomers [methacryloxyethyl benzyl dimethyl ammonium chloride (DMAE-BC), methacryloxyethyl m-chloro benzyl dimethyl ammonium chloride (DMAE-m-CBC), methacryloxyethyl cetyl dimethyl ammonium chloride (DMAE-CB)] were synthesized according to the general structure of target monomers. Their antibacterial effects were investigated using the broth dilution test on Gram-positive and Gram-negative bacterial strains (Streptococcus mutans, Streptococcus sanguis, Porphyromonas gingivalis, Prevotella melaninogenica ). Three different monomers were successfully obtained. All the tested bacterial strains were susceptible to the three monomers, among which DMAE-CB exhibited the lowest minimal inhibitory concentrations (MIC) ranging from 1.2 to 4.8 mg/L. All these three QAS monomers have different antibacterial activities against four oral bacteria strains. The data indicate that DMAE-CB may be a candidate antibacterial agent for oral infectious diseases.

Antibacterial effects of three experimental quaternary ammonium salt (QAS) monomers on bacteria associated with oral infections

The aim of this study was to test the antibacterial effects of three experimental quaternary ammonium salt monomers in order to evaluate their potential applications as dental materials. In vitro susceptibility testing of the monomers was performed by the broth dilution method on bacteria associated with oral infections: Streptococcus mutans ATCC 25175, Actinomyces viscosus ATCC 15987, Staphylococcus aureus ATCC 29213 and Lactobacillus casei ATCC 393. The time-kill kinetics of the monomer with relatively higher antibacterial activity against S. mutans were also investigated. It was found that all the tested bacteria strains were susceptible to the three monomers, among which methacryloxylethyl cetyl ammonium chloride (DMAE-CB) exhibited the lowest minimal inhibitory concentrations, ranging from 1.2 to 4.8 microg/ml. The time-kill curve showed that DMAE-CB achieved 99.44% killing at 19.2 microg/ml (4 times the minimal bactericidal concentration) against S. mutans after 1 min and 100% killing within 10 min of contact. This result indicates that the quaternary ammonium salt monomer DMAE-CB may be a candidate antibacterial agent for incorporation into dental restorative materials.

Studies on a Cationically Modified Quaternary Ammonium Salt of Lignin

A new quaternary ammonium salt monomer was synthesized and a quaternary amination of lignin(noted as QL), with the monomer was carried out by grafting copolymerization. The products were characterized by Fourier Transform Infrared spectroscopy(FTIR). The experimental results indicate that the yield of the monomer was 99.06%, and the conversion of the monomer and the grafting yield of QL were 93.69% and 185.78%, respectively. The feasibility of QL as the flocculant to be applied in color removal of five artificial dyes, eriochrome black T(dye A), gongo red(dye B), direct fast black G(dye C), cuprofix blue green B(dye D), and acid black ATT(dye E) was examined. Results show that QL exhibits the favorable flocculation performance and high stability.

Table Salt and Other Alkali Metal Chloride Oligomers: Structure, Stability, and Bonding

We have investigated table salt and other alkali metal chloride monomers, ClM, and (distorted) cubic tetramers, (ClM)(4), with M = Li, Na, K, and Rb, using density functional theory (DFT) at the BP86/TZ2P level. Our objectives are to determine how the structure and thermochemistry (e.g., Cl-M bond lengths and strengths, oligomerization energies, etc.) of alkali metal chlorides depend on the metal atom and to understand the emerging trends in terms of quantitative Kohn-Sham molecular orbital (KS-MO) theory. The analyses confirm the high polarity of the Cl-M bond (dipole moment, VDD, and Hirshfeld atomic charges). They also reveal that bond overlap derived stabilization (approximately -26, -20, and -8 kcal/mol), although clearly larger than in the corresponding F-M bonds, contributes relatively little to the (trend in) bond strengths (-105, -90, and -94 kcal/mol) along M = Li, Na, and K. Thus, the Cl-M bonding mechanism resembles more closely that of the even more ionic F-M bond than that of the more covalent C-M or H-M bonds. Tetramerization causes the Cl-M bond to expand, and it reduces its polarity.