Monomer Polymer Research Articles

Synthesis and characterization of ionic liquid polymer composite with zeolite and its application for carbon dioxide capture

Among the different ways to capture carbon dioxide (CO2), ionic liquid technology is one of the prominent approaches and gained the interest of researchers to improve this technology from time to time. In this study, we have prepared and characterized a novel ionic liquid polymer composite with zeolite and tested its efficiency to capture CO2. The ionic liquid monomer, 1-vinyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide [Veim][Tf2N] was polymerized through free radial polymerization process adding zeolite to form poly[Veim][Tf2N] zeolite polymer composite. The synthesized polymer ionic liquid zeolite composite was characterized by FT-IR, FE-SEM and EDX. The formation of polymer ionic liquid zeolite composite was indicated by the presence of zeolite peaks in FT-IR spectra. Additionally, the EDX results were confirmed the presence of zeolite in the prepared composite. Finally, to prove the efficiency of prepared polymer ionic liquid zeolite composite, the adsorption studies have been conducted using CO2 adsorption cell. The results revealed the capability of ionic liquid zeolite polymer composite in adsorbing high amount of CO2 and recorded the highest pressure drop compared to other polymer ionic liquid and monomer ionic liquid materials.

One-Step Preparation of Tough and Self-Healing Polyion Complex Hydrogels with Tunable Swelling Behaviors.

Polyion complex (PIC) hydrogels formed by charge attraction of opposite charged polymers have received unique research interest. Their conventional preparation method, with a large amount of residual salt after polymerization, requires a long-term dialysis treatment to remove the salt and toughen the gel. Here, a promising strategy for the one-step preparation of tough PIC hydrogels without dialysis after polymerization is provided. Bicarbonate and proton ions are selected as the counter ions of the cationic monomer and anionic polymers, respectively. By a CO2 -generating reaction between the counter ions, the residual salt is removed before polymerization, and thus, a PIC hydrogel with tough mechanical performance can be obtained instantly without dialysis. Due to the absence of dialysis, the tough hydrogel can be formed with a wide range of ratios for the oppositely charged polymer with distinct swelling behaviors from non-swelling to super-swelling. This tunable swelling behavior shows the possibility for shape-morphing systems from this one-step method.

Evaluating the temperature dependence of heat-transfer based detection: A case study with caffeine and Molecularly Imprinted Polymers as synthetic receptors

Molecularly Imprinted Polymers (MIPs) are synthesized for the selective detection of caffeine. The polymerization process, monomer and crosslinker monomer composition are varied to determine the optimal synthesis procedure via batch rebinding experiments evaluated with optical detection. The selectivity is tested by comparing the response of caffeine to compounds with similar chemical structures (theophylline and theobromine) and dopamine, another neurotransmitter. Subsequently, the MIP polymer particles are integrated into bulk modified MIP screen-printed electrodes (MIP-modified SPEs). The sensors are used to measure caffeine content in various samples employing the Heat-Transfer Method (HTM), a low-cost and simple thermal detection method that is based on differences in thermal resistance at the solid-liquid interface. At first, the noise is minimized by adjusting the settings of temperature feedback loop. Second, the response of the MIP-modified SPE is studied at various temperatures ranging from 37 to 50 and 85 °C. The binding to MIP-modified SPEs has never been studied at elevated temperatures since most biomolecules are not stable at those temperatures. Using caffeine as proof-of-concept, it is demonstrated that at 85 °C the detection limit is significantly enhanced due to higher signal to noise ratios and enhanced diffusion of the biomolecule. Thermal wave transport analysis (TWTA) is also optimized at 85 °C producing a limit of detection of ∼1 nM. Next, MIP-modified SPEs are used to measure the caffeine concentration in complex samples including caffeinated beverages, spiked tap water and waste water samples.The use of MIP-modified SPEs combined with thermal detection provides sensors that can be used for fast and low-cost detection performed on-site, which holds great potential for the determination of contaminants in environmental samples. The platform is generic and by adapting the MIP layer, we can expand to this a range of relevant targets.

Plasmon‐Polariton Induced, “from Surface” RAFT Polymerization, as a Way toward Creation of Grafted Polymer Films with Thickness Precisely Controlled by Self‐Limiting Mechanism

AbstractPlasmon‐induced “from surface” reversible addition‐fragmentation chain‐transfer (RAFT) polymerization is reported for the first time. The gold grating surface, supporting the surface plasmon polariton excitation and propagation, is grafted with RAFT agent, immersed in the solution, containing the NIPAm monomer and AIBN and subsequently illuminated at a wavelength corresponding to plasmon absorption. The grafting of the polymer layer, its thickness, and morphology are characterized by several techniques (including the surface‐enhanced Raman spectroscopy (SERS), scanning electron microscopy and energy‐dispersive X‐ray spectroscopy (SEM‐EDX), X‐ray photoelectron spectroscopy (XPS), nanomechanical atomic force microscopy (AFM) mapping, and goniometry). It is shown that the polymerization efficiently starts only under the surface plasmon‐polariton excitation. The time‐dependent SERS and XPS measurements indicate rather self‐limiting nature of plasmon‐induced “from the surface” PNIPAm growth, namely the reaction takes place up to a certain polymer thickness and is stopped despite a significant excess of polymerization initiator and monomer in the reaction solution. The present results provide the basis for designing further experiments on plasmonic catalysis in general and offer a new way of producing ultrathin polymer films with a defined structural dimension.

Stability of Polymer–Monomer Particles of Synthetic Latexes

The presence of “living” macroradicals in the volume of a polymer–monomer particle may be one of the factors responsible for the loss of the aggregative stability of latexes. If the adsorption protection of a polymer–monomer particle is insufficient, high content of “living” macroradicals leads to gelation in the latex in the course of storage. Correlation between the latex life time, hydration of nonionic surfactant molecules in the adsorption layer of a polymer–monomer particle, and extent of the action of the macroradicals was determined. Naphthalenesulfonic dispersing agents enhance the stability of latex systems in the step of polymerization and distillation of the monomers owing to a decrease in the critical micelle concentration of the emulsifier, to extension of the micellar period of the polymerization, to an increase in the degree of saturation of polymer–monomer particles, and to an increase in the probability of macroradical recombination in the volume of a polymer–monomer particle. With an increase in the degree of polycondensation of naphthalene-containing dispersing agents, their surface activity increases, whereas the ability to support the aggregative stability of latexes decreases.

Cooperative supramolecular polymers with anthracene\u2012endoperoxide photo-switching for fluorescent anti-counterfeiting

Innovative technologies are highly pursued for the detection and avoidance of counterfeiting in modern information society. Herein, we report the construction of photo-responsive supramolecular polymers toward fluorescent anti-counterfeit applications, by taking advantage of multicycle anthracene‒endoperoxide switching properties. Due to σ-metalation effect, photo-oxygenation of anthracene to endoperoxide is proceeded under the mild visible light irradiation conditions, while the backward conversion occurs spontaneously at room temperature. Supramolecular polymers are formed with cooperative nucleation‒elongation mechanism, which facilitate fluorescence resonance energy transfer process via two-component co-assembly strategy. Fluorescence resonance energy transfer efficiency is delicately regulated by either light-triggered anthracene‒endoperoxide conversion or vapor-induced monomer–polymer transition, leading to high-contrast fluorescent changes among three different states. On this basis, dual-mode anti-counterfeiting patterns have been successfully fabricated via inkjet printing techniques. Hence, cooperative supramolecular polymerization of photo-fluorochromic molecules represents an efficient approach toward high-performance anti-counterfeit materials with enhanced security reliability, fast response, and ease of operation.

Lipase immobilization on high water adsorbing capacity bagasse: applications in bio-based plasticizer synthesis.

This study investigates the structure and water adsorbing capacity of bagasse and of sodium hydroxide pretreated bagasse. The structures of bagasse and bagasse-NaOH were compared by SEM and XRD. Candida antarctica lipase B was then immobilized on bagasse, bagasse-NaOH and DPA@bagasse-NaOH. The expressed activity and immobilization yield of lipase immobilized on bagasse-NaOH (1.0%) was 36% and 45% higher than that on bagasse. When dopamine (DPA) was used as cationic polymer monomer via self-polymerization for mediating immobilization, the protein loading amounts and activity of lipase immobilized on DPA@bagasse-NaOH were higher than that of bagasse-NaOH. When the DPA concentration was 100mg/ml, the immobilized lipase expressed activity reached its highest value (800 U/g), where the immobilization yield achieved 96.8%, which was 3.93-fold of lipase immobilized on native bagasse (24.6%). Then the immobilized lipases were used to synthesize a bio-based plasticizer. Lipase immobilized on DPA@bagasse-NaOH exhibited a significantly improved operational stability. Even after 12 batches, a high ester yield (84.2%) was maintained. Additionally, poly (vinyl chloride) PVC blends plasticized with methyl oleate as a secondary plasticizer were investigated. It was discovered that methyl oleate can be used as an effective bio-based plasticizer for PVC. These results indicate that bagasse with high water adsorbing capacity and self-polymerized DPA layer could create a favorable microenvironment for bio-based plasticizer synthesis in esterification reactions.

Photochromic Monomer and Coordination Polymer Based Hybrid Tetra-arylethenes

New multifunctional tetra-arylethene and its one-dimensional coordination polymer were constructed. Their structures were confirmed and the behavior of photochromism and fluorescence were investiga...

Experimental study of acrylamide monomer polymer gel for water plugging in low temperature and high salinity reservoir

ABSTRACTWater plugging agent has been widely applied on oilfield EOR processes for decades. Conventional plugging agents used on reservoirs with low temperature (50°C) and high salinity (28.6 × 104 mg/L) encounters with some limitations, such as slow gelling, weak gel strength, and poor instability. To overcome these problems, a novel acrylamide monomer polymer gel with strong gel strength, controllable gelling time and good stability was developed. The gelation processes of the plugging agent system at low temperature and high salinity is studied. The cross-linking reaction process of plugging agent is found to be in three stages: induction stage, rapid cross-linking, and stable stage. The composition of this plugging agent system is optimized: 5~7.5 wt% acrylamide + 0.5~0.75 wt% cross-linking agent + 0.005 ~0.12 wt% retarder + 0.5 wt% initiator. The plugging rate is over 96.5% in high permeability sandpack. It also displays good shear resistance. With the continuous flooding by water after the gel is formed, the polymer gel shows good flooding resistance. It can block the water effectively until 10 PV of injected water.

Molecular Imprinted Polymer Based Impedimetric Sensor for Trace Level Determination of Digoxin in Biological and Pharmaceutical Samples

Background: Molecularly Imprinted Polymers (MIPs) are used as artificial receptors in biosensors for the detection of a wide range of analytes from small drug molecules to large molecular weight biomolecules. Quantification of Digoxin (DIG) in human serum and pharmaceutical samples has very high importance due to its low margin of safety. In this report, a highly sensitive molecularly imprinted polymer for DIG is prepared and the detection of analyte was conducted using electrochemical impedance spectroscopy. Methods: Bulk polymerization method was chosen for the preparation of MIP because of its better preservation of the pockets formed during the polymerization. DIG imprinted polymer was prepared by thermal polymerization of Methacrylic Acid (MAA) cross-linked with Ethyleneglycol Dimethacrylate (EGDMA) in the presence of DIG. The molecular interactions via hydrogen bonding between template and monomer in MIP and Non-Imprinted Polymer (NIP) were confirmed using Fourier Transform Infrared (FTIR) spectroscopy. Morphological studies were performed before and after extraction of the template using Scanning Electron Microscopy (SEM). MIP modified carbon paste electrode (MIPCPE) was fabricated by mixing optimized quantities of graphite, the polymer, and eicosane. The change in charge transfer Resistance (Rct) at the electrode-electrolyte (MIPCPE-electrolyte) interface before and after addition of DIG solution was studied using electrochemical impedimetric sensing of DIG. Results: The surface morphology of the MIPCPE shows better porosity in comparison to non-imprinted polymer CPE (NIPCPE) and MIPCPE before extraction of the template. In contrast to NIPCE, the fabricated MIPCPE shows a significant increase in Rct after addition of DIG. The MIPCPE based impedimetric sensor is able to detect DIG over a wide range of concentration from 1.0 × 10-9 M to 0.5 × 10-7 M with a detection limit 6.95 × 10-11 M. The selectivity coefficients obtained for the MIPCPE and NIPCPE reveal specific recognition MIPCPE sensor towards DIG. The recovery rates of DIG from the spiked blood serum and pharmaceutical samples are in the range of sensor 89-101%. Conclusion: In the present work, the capability of MIPs as molecular recognition elements is proved by reporting a selective and sensitive impedimetric sensor for DIG. The selectivity coefficients (K) of MIPCPE and NIPCPE obtained for the DIG and interferents show better selectivity of the sensor towards DIG in the presence of interferents. The proposed sensor also shows satisfactory stability, reproducibility, and repeatability for DIG. The proposed sensor was successfully applied for the quantitative estimation of DIG in serum and pharmaceutical samples with appreciable recoveries. Keywords: Digoxin, molecularly imprinted polymer, free-radical polymerization, scanning electron microscope, electrochemical impedance spectroscopy, Carbon paste electrode.

On Demand Switching of Polymerization Mechanism and Monomer Selectivity with Orthogonal Stimuli.

The development of next-generation materials is coupled with the ability to predictably and precisely synthesize polymers with well-defined structures and architectures. In this regard, the discovery of synthetic strategies that allow on demand control over monomer connectivity during polymerization would provide access to complex structures in a modular fashion and remains a grand challenge in polymer chemistry. In this Article, we report a method where monomer selectivity is controlled during the polymerization by the application of two orthogonal stimuli. Specifically, we developed a cationic polymerization where polymer chain growth is controlled by a chemical stimulus and paired it with a compatible photocontrolled radical polymerization. By alternating the application of the chemical and photochemical stimuli the incorporation of vinyl ethers and acrylates could be dictated by switching between cationic and radical polymerization mechanisms, respectively. This enables the synthesis of multiblock copolymers where each block length is governed by the amount of time a stimulus is applied, and the quantity of blocks is determined by the number of times the two stimuli are toggled. This new method allows on demand control over polymer structure with external influences and highlights the potential for using stimuli-controlled polymerizations to access novel materials.

Investigation of the Extracellular Matrix Effect for the QCM/CCD Cell Activity Monitoring System.

A real-time quartz crystal microbalance (QCM) cell activity monitoring system coupled with micro CCD cameras was developed to investigate the cultured cell activity, which could measure the viscoelastic characteristics of the cell with the QCM and observe the cell morphology changes with CCD camera simultaneously. Both the viscoelastic characteristics and the shape of the cultured cell are important factors to estimate the cell activity and the cell adhesion. The extracellular matrix (ECM) on the surface of the QCM is essential to culture the cell stably in the QCM monitoring system. To find the ECM optimization condition, the adhesive strength of cultured cells on the ECM modified glass surface was measured by using rotating water stream and CCD camera. After culturing HepG2 cells for 24 hours on the ECM modified glass plates, the glass plates were dipped in the PBS solution and rotated with 1,000, 1,300, and 1,500 rpm for 30 seconds. The adhesiveness of ECMs was investigated by calculating the remained cells after rotating. Four types of ECM, such as amino group, carboxyl group, collagen monomer, and collagen polymer, were used and tested. The current paper improves the sensing system of previous report so that measurements of four ECMs can be simultaneously conducted under the same conditions in order to enhance reliability. A collagen polymer exposed ECM was the most stable on an adhesiveness point of view, but not suitable for the QCM cell activity monitoring due to the decrease of the QCM sensitivity. The sensitivity of the QCM cell activity monitoring system using collagen monomer as ECM is about 2.6 times better than that using collagen polymer. A collagen monomer exposed ECM was more stable than amino group and carboxyl group exposed ECMs based on an adhesiveness point of view. Therefore, a collagen monomer exposed ECM was the most stable and suitable for the QCM cell activity monitoring system among the four ECMs. The changes of the resonance frequency and the resonance resistance of the ECM film with the cultured cells were investigated and compared the results of CCD camera images. From these results, we showed the QCM cell activity monitoring system coupled with the micro CCD camera could be applied to the evaluation of the cell activities.

A triphenylamine-based polymer with anthraquinone side chain as cathode material in lithium ion batteries

A triphenylamine-based polymer poly[N-(anthraquinone-2-yl)-N,N-diphenylamine] (PDPA-AQ) with anthraquinone side chain was synthesized by a simple chemical oxidative polymerization. Due to the introduction of anthraquinone units with a high specific capacity in the side chain, the polymer PDPA-AQ has a high theoretical specific capacity, about twice of polytriphenylamine (PTPA). The lithium ion batteries based on PDPA-AQ as cathode active material and lithium foil as anode were assembled and their electrochemical properties were investigated. For a comparison, the electrochemical performance of the monomer DPA-AQ was also studied. Both monomer DPA-AQ and polymer PDPA-AQ have high initial discharge specific capacity, about 129 mAh g−1 and 159 mAh g−1 respectively, which are higher than the theoretical specific capacity of PTPA-based cells. The polymer PDPA-AQ has better discharge specific capacity, cycle performance and rate performance than monomer DPA-AQ, which shows that the design idea of introducing an electrochemically active carbonyl compound into the polytriphenylamine side chain can improve the specific capacity of the PTPA.

Soluble, thermally stable, flame retardant quinoline-based poly(ester amide)s

ABSTRACTA new diamine was prepared via reaction between 8-hydroxy-5-nitroquinoline and 4-nitrobenzoyl chloride, followed by reduction of the nitro groups of the resulted compound. Novel quinoline-based poly(ester-amide)s were produced through polycondensation reactions of the prepared diamine with different diacid chlorides. The monomer and poly(ester-amide)s were characterized and properties of the polymers including solution viscosity, thermal behavior and stability, solubility, and crystallinity were studied.High thermal stability and improved solubility was observed for the polymers, indicating successful designing of monomer and related polymers for overcoming the main issue of thermally stable polymers, i.e. the problem of increasing solubility versus high thermal stability.Also, by changing the diacid chlorides for the preparation of poly(ester-amide)s, the structure-property relations were investigated.

Investigation of radical polymerization kinetics of poly(ethylene glycol) methacrylate hydrogels via DSC and mechanistic or isoconversional models

Monomers composed of a polymerizable methacrylate moiety connected to a short poly(ethylene) glycol (PEG) chain are versatile building-blocks for the preparation of “smart” biorelevant materials. Hydrogels based on these PEG methacrylates are a very important class of biomaterials with several applications. The radical polymerization kinetics of two such oligomers, namely poly(ethylene glycol) methacrylate (PEGMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) was investigated. Experimental polymerization rate and monomer conversion data were measured using DSC operating under non-isothermal conditions, at several constant heating rates, or isothermal, at different constant reaction temperatures. Isoconversional techniques were employed to estimate the variation of the polymerization effective activation energy as a function of the extent of reaction. It was found that isothermal and non-isothermal experiments results in similar trends of the activation energy, whereas by comparison of differential to integral isoconversional methods it was postulated that in non-isothermal polymerization experiments integral methods should not be used. From comparison of the two oligomers employed in the polymerization experiments, it was clear that the presence of the terminal hydroxyl group in PEGMA compared to the methoxy group in PEGMEMA leads to different conversion time profiles and activation energies. In particular, monomer–monomer association through hydroxyl groups results in initially lower activation energy of PEGMA. As polymerization proceeds, the existence of aggregated hydroxyl structures (···OH···OH···OH···) in the PEGMA macromolecular chains result in higher activation energies and a more abrupt increase in the conversion time curve.

Modeling of ethylene copolymerization in nonisothermal high‐pressure reactors using bifunctional initiators

Enhancing the performance of high‐pressure LDPE process is valuable for polymer industry. However, the severe thermodynamics requirement of high pressure and temperature hinders the reaction process from getting simultaneously high monomer conversion and polymer molecular weights. Bifunctional peroxides used as initiators can boost the polymerization rate and alter rheological polymer properties. This article proposes a new kinetics model of ethylene/butyl acrylate copolymerization with bifunctional initiators in a high‐pressure nonisothermal tubular reactor. Model predictions are compared with available data. A SQP optimization scheme is employed to determine a suitable wall temperature for each zone along the nonisothermal tubular reactor. In comparison with the monofunctional TBPPI peroxide, a lower amount of the bifunctional DHBPPI peroxide is needed to get a higher conversion in shorter residence time, but at the expense of higher thermal energy. The results also showed that polymers produced with bifunctional peroxides are significantly more branched. POLYM. ENG. SCI., 59:74–85, 2019. © 2018 Society of Plastics Engineers

Cultivation temperature modulated the monomer composition and polymer properties of polyhydroxyalkanoate synthesized by Cupriavidus sp. L7L from levulinate as sole carbon source

Cupriavidus sp. L7L, a newly isolated wild-type soil bacterium, was found to synthesize polyhydroxyalkanoate (PHA) terpolymers from levulinic acid (LA), a top bio-based platform chemical, as the sole carbon source. NMR spectra showed that the terpolymers consisted mainly of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and a small amount (2.1–4.8 mol%) of 4-hydroxyvalerate (4HV). The combination of monomers together with high molecular weights improved markedly the thermal and mechanical properties of the terpolymers. Increasing cultivation temperature of Cupriavidus sp. L7L increased the proportions of 3HB and decreased the proportions of 3HV. A fed-batch fermentation using LA as the sole carbon source without pH control produced a biomass of 15.8 dry weight g L−1 that contained 81 dry weight% of a terpolymer P(3HB-co-33.7 mol% 3HV-co-2.1 mol% 4HV), equaling a productivity of 0.213 g PHA L−1 h−1. The terpolymer showed a melting point of 92 °C and elongation at break of 630%, compared to 84.6 °C and 462%, respectively, for the copolymer P(3HB-co-35.9 mol% 3HV) that contained no 4HV. This study showed that Cupriavidus sp. L7L exhibited a great potential for producing PHA polymers with excellent mechanical property that could be modulated by cultivation temperature when cultivated exclusively in LA.

Radical Polymerization of Protonated Diallylammonium Monomers in Bidistilled Aqueous Solution: Kinetic Study

The kinetics of the radical polymerization of protonated monomers of the diallylammonium series (diallyl- and diallylmethylammonium trifluoroacetates) in bidistilled aqueous solution (quartz bidistiller) is studied in situ using 1Н NMR spectroscopy. The rates of monomer consumption and polymer accumulation in the range of 30–50°С are determined. For diallylammonium trifluoroacetate, the effective activation energy of polymerization and the constant of chain transfer to the monomer (30°С) are estimated. It is found that the initial rates of polymerization are comparable with the rates of polymerization of quaternized analogs and the constant of chain transfer to the monomer and the activation energy of polymerization are close to the analogous characteristics of polymerization in the case of quaternized diallyldimethylammonium chloride. It is shown that for polymerization in bidistilled solution, the constant of chain transfer to the monomer (30°С, 3.8 × 10–3) is more than three times lower than that for polymerization in monodistillate (30°С, 12.2 × 10–3) and the ММ of the polymers is ~2.4 times higher than the ММ of the samples synthesized in monodistillate under the same conditions. It is ascertained that standard electrolyte admixtures in distilled aqueous solution considerably affect radical chemical reactions involving protonated forms.

Diversified Aggregation States of Phospholyl Lithiums

Studies on the aggregation states of phospholyl lithiums are of great importance and demand due to their applications as ligands in coordination chemistry. In this paper, we report that the solid-state structures of phospholyl lithiums with different substituents (2a,b, R1 = Ph, R2 = TMS; 3a,b, R1 = Me, R2 = TMS; 4, R1 = R2 = Et) could be in the form of a monomer, dimer, and coordination polymer, respectively. These phospholyl lithiums can change to monomeric structures (5, R1 = Ph, R2 = TMS; 6, R1 = Me, R2 = TMS; 7, R1 = R2 = Et) when the lithium cations are chelated by 12-crown-4.

PRODUCTION OF CASTOR OIL MALEATE USING DI-TERT-BUTYL PEROXIDE AS FREE RADICAL CATALYST

Abstract Castor oil maleate is used in healthcare products, synthetic lubricants, drying oils, water-soluble paints and as a monomer in several polymers. This compound is formed by direct reaction between castor oil and maleic anhydride, which can be accelerated using free radical catalysts. In this work, the influence of processing temperature and the concentration of di-tert-butyl peroxide (DTBP) in the production of castor oil maleate was studied applying response surface methodology. The results showed that the use of the radical initiator increased the rate of reaction, leading to a shorter reaction time and higher productivity. The optimal operating condition was found at 120oC, 1 mol of maleic anhydride/mol of castor oil and 0.005 mol of DTBP/mol of castor oil, yielding 90.2% of castor oil maleate in 90 min.