Acrylonitrile Copolymer Research Articles

Oxygen Reduction on Catalysts Prepared by Pyrolysis of Electrospun Styrene–Acrylonitrile Copolymer and Multi-walled Carbon Nanotube Composite Fibres

For the first time, the oxygen reduction reaction (ORR) is studied on pyrolysed electrospun multi-walled carbon nanotube (MWCNT) and styrene–acrylonitrile (SAN) composite fibre catalysts in alkaline medium. Scanning electron microscopy images revealed that the prepared catalysts mainly consist of MWCNTs, while nitrogen doping of the catalysts is confirmed by X-ray photoelectron spectroscopy. This indicates that SAN can be used as a nitrogen precursor. The ORR studies carried out by rotating disc electrode (RDE) and rotating ring-disc electrode (RRDE) methods showed that the prepared catalysts were considerably more active towards the ORR than the pristine MWCNTs.

The cyclization index and toughness of gel spun polyacrylonitrile (PAN) proportionality with its heat of stabilization

The spun tapes of synthesized PAN, its copolymer with 1 wt% itaconic acid, and doped version with 1 wt% sodium dodecyl sulfate (SDS) all showed stripy, even, and compact cross-sections as the hallmark of gel forming products. PAN doping with SDS and acrylonitrile copolymerization with itaconic acid reduced its dimethylformamide (DMF) solution structural viscosity index (Δη) by 50% and 30%, respectively, at 675 s− 1. In addition, the modification of synthesized PAN through doping and acrylonitrile copolymerization with itaconic acid led to severe and mild gelation temperature decrease, respectively. The stabilization peak of the synthesized PAN tape was enhanced as much as 25 °C by 900% hot drawing, decreased by about 10 °C through copolymerization, while experienced small temperature changes through doping. The second derivative of Fourier transform infrared and Gaussian fitting was used to analyze the tapes cyclization due to stabilization treatment through introducing Isd index. 10 min Isd index was raised as much as 430% and 800% in comparison with the synthesized PAN through its doping or acrylonitrile copolymerization with itaconic acid, respectively. Further 180 min of Isd index, however, showed the same proportional increase as toughness of the drawn tapes versus their heat of stabilization through their physical and chemical modifications.

Molecular Imprinted Polymer Based Electrode for Sensing Catechin (+C) in Green Tea

Green tea is believed to be a healthy beverage due to a number of therapeutic benefits. Catechin, one of its constituents, is an important antioxidant and possesses free radical scavenging abilities. This paper demonstrates a low cost solution related to the sensing of catechin (+C) using the principle of molecular imprinted polymer technique. Here the electrode was synthesized using the co-polymer of acrylonitrile and ethylene glycol dimethacrylate and was subsequently imprinted with catechin. The material was extensively characterized using Fourier transform infra-red spectroscope and field emission scanning electron microscope, respectively. Cyclic voltammetry and differential pulse voltammetry using the three electrode system were employed for determining the electrochemical characteristics of the proposed electrode. It exhibited a linear range from 5 to 100 $\mu \text{M}$ with the limit of detection of 37 nm (S/N = 3). On studying the analytical characteristics, the electrode was found to be repeatable, reproducible, and offered a good selectivity. Our sensing device was subjected to green tea samples in order to study their catechin content. A partial least square regression model was developed for correlating the response with that of the high performance liquid chromatography data and it resulted in a prediction accuracy of about 92%.

Acrylonitrile copolymer/graphene skinned cathode for long cycle life rechargeable hybrid aqueous batteries at high-temperature

For aqueous rechargeable lithium battery (ARLB), excellent cycling stability at elevated temperature is highly desirable in its application of electric vehicles (EVs). However, most state-of-art ARLBs show poor durability under high-temperature operation. Herein, we demonstrate a facile coating approach that can construct a thin acrylonitrile copolymer (ANC)/graphene skin on the top-surface of the LiMn2O4 (LMO) cathode in a rechargeable hybrid aqueous lithium battery (ReHAB). Featuring the continuous coverage and the facile electron transport, the ANC/graphene skinned cathode shows a capacity retention of 61% after 300 cycles at 60 °C, two times larger than the battery without the skin. In the cathode, ANC helps to suppress unwanted interfacial side reactions, and graphene renders a robust ion diffusion framework. Quantitative analysis of Mn suggests that the ANC/graphene skin can greatly suppress dissolution of Mn from the LMO into the aqueous electrolyte, while maintaining the charge transfer kinetics. The polymer-based nanocomposite skin on small (1.15 mAh cell) and large (7 mAh cell) cathodes show similar electrochemical improvement, indicting good scale-up potentials.

Calculating the Ionization Constant of Functional Groups of Carboxyl Ion Exchangers

The potentiometric titration of a weakly basic carboxyl cation exchanger, obtained via alkaline hydrolysis of an acrylonitrile copolymer with divinyl benzene (degree of crosslinking, 12%) in a wide range of variation in a solution of рН (2–12) and NaCl (concentration 0.01, 0.1, 0.5, 1 М), is considered. The maximum ion-exchange capacity of the ion exchanger for Na+ is determined (10.10 ± 0.088 mmol/g of the dry mass) and found to be independent of the solution’s ionic strength. It is established that in the investigated range of NaCl concentrations and рН, the acid–base balance is adequately described by Gregor’s equation. The parameters of this equation are calculated as a function of the NaCl concentration: рKа = 8.13 ± 0.04, n = 1.50 ± 0.02 for 0.01 М; рKа = 6.56 ± 0.04, n = 2.60 ± 0.07 for 0.1 М; and рKа = 5.66 ± 0.6, n = 2.62 ± 0.06 for 0.5 and 1 М. It is shown that to describe the acid–base balance correctly within the proposed model we must estimate the adequacy of the experimental and calculated values of the ion exchanger’s capacity at each рН value according to the calculated parameters of Gregor’s equation.

Ионообменные свойства материалов на основе волокнообразующих сополимеров акрилонитрила с различными кислотными сомономерами

Ионообменные свойства материалов на основе волокнообразующих сополимеров акрилонитрила с различными кислотными сомономерами

Surface decontamination in fuel manufacture plants by chelating solution of nanoparticles

Abstract A nanoparticles chelating solution was synthesized by copolymerization of acrylonitrile (AN) and methacrylic acid (MAA) by radiation induced polymerization technique using 17 kGy irradiation doses. A high copolymer yield was obtained by using 80/20% of AN/MAA and comonomer concentration of 50% (w/w) at a dose rate of 2.58 KGy/h. The resultant cyano group (–CN) of nano-poly(AN/MAA) was converted by chemical modification using hydroxylamine (NH2–OH) to an amidoxime group [–C(=NOH)NH2], which was then confirmed by Fourier transform infrared spectroscopy (FTIR). The physico-chemical properties of poly(AN/MAA) and amidoximated poly(AN/MAA) nanoparticles were studied by FTIR, transmission electron microscopy (TEM), dynamic light scattering (DLS) and thermal gravimetric analysis (TGA). The morphological analysis by TEM and DLS showed a spherical and uniform size of the amidoximated poly(AN/MAA) nanoparticles. TGA results indicated that the thermal stability of poly(AN/MAA) increased by the amidoximation process. The surface decontamination due to uranium was also investigated by the prepared chelating nanoparticles solution. A high purity germanium detector (HPGe) was used as a surface contamination detection tool. The results showed the presence of peaks at different energies, namely, 186.2 keV for Ra-226 (U-238) and 143.76 keV, 163.35 keV and 205.31 for U-235 before the decontamination process. The disappearance of these peaks after decontamination confirmed the applicability and efficiency of the nanoparticles solution in uranium surface decontamination.

Compatibilizer Assistant SCF/ABS Composites with Improved Mechanical Properties Prepared by Fused Deposition Modeling

ABSTRACTA random terpolymer copolymer of styrene, acrylonitrile and glycidyl methacrylate (SAG) was used as compatibilizer to improve the interfacial adhesion of short carbon fiber (SCF)/acrylonitrile-butadiene-styrene (ABS) composites. Effects of SAG on the structural and mechanical properties of fused deposition modeling (FDM) printed composites were investigated. The results showed the addition of SAG could effectively improve the interfacial adhesion between SCF and ABS matrix, whereas slightly decrease average length of SCF and degrade the adhesion quality among deposited filaments. As a result, the tensile and flexural properties of FDM printed composites initially increased and then decreased with the SAG content.

Synthesis, characterization and antimicrobial activity of Schiff bases modified chitosan-graft-poly(acrylonitrile)

Graft copolymerization of chitosan (Ch) with acrylonitrile (AN) prepared by free radical polymerization using potassium persulfate (PPS) as initiator. Optimization of Graft copolymerization of acrylonitrile on to chitosan was performed by studying the main parameters that affecting the grafting process such as initiator and monomer concentrations, reaction time and temperature of the polymerization process to study their influence on percent grafting (G%), grafting efficiency (GE%) and percent homopolymer (H%). Modification of grafted chitosan was done by Schiff’s base derivatives using different aldehydes. They are characterized by FT-IR, X-ray diffraction, thermal analysis and scanning electron microscope. Their antibacterial activities against Streptococcus pneumonia (RCMB 010010), Staphylococcus aureus (RCMB 010028), as Gram-positive bacteria and Escherichia coli (RCMB 010052) as Gram-negative bacteria and the antifungal activity against Aspergillus fumigatus (RCMB 02568), Candida albicans (RCMB 05036) and Geotricum candidum (RCMB 05097) were examined using the diffusion agar technique. The obtained data proved that modified chitosan by grafting show better antimicrobial activities than Chitosan. Also Schiff base derivatives showed better antimicrobial activities than grafted chitosan.

Localization of Failures in Structural Order of trans-1,4-Butadiene Units in Interdefective Regions of a Butadiene-Nitrile Elastomer Matrix

The fractional free volume of chains passing and incorporated into the ordered structures of segments in trans-1,4-configuration in the copolymers of butadiene and acrylonitrile at different content of acrylonitrile units is calculated in order to determine the localization of order disturbances of butadiene trans-1,4-units. Amorphization of the structure occurs in the immediate vicinity of structural defects of acrylonitrilebutadiene rubbers formed by alternating acrylonitrile and trans-1,4-units of butadiene as well as cis-1,4-and 1,2-isomers of butadiene.

Adsorption of Nafamostat Mesilate on AN69ST Membranes: A Single-Center Retrospective and In Vitro Study.

We examined whether AN69ST (acrylonitrile and methallyl sulfonate copolymer) membranes adsorb nafamostat mesilate. This study retrospectively analyzed 87 continuous hemodiafiltration sessions in vivo. We divided the continuous hemodiafiltration sessions into AN69ST and non-AN69ST groups using the nafamostat mesilate dose and activated clotting time as indicators of nafamostat mesilate adsorption onto the membrane. Furthermore, we studied the in vitro adsorption of nafamostat mesilate from nafamostat mesilate solutions onto four different hemodialysis membranes. This in vivo study shows that nafamostat mesilate doses were significantly higher, but activated clotting times were shorter (P < 0.001) in the AN69ST group than in the non-AN69ST group. These results suggest that AN69ST adsorbs nafamostat mesilate. Further, the in vitro experiments show that nafamostat mesilate adsorbs AN69ST on membranes significantly more than the other membranes tested. These in vitro and clinical findings provide evidence that AN69ST may adsorb nafamostat mesilate.

Study on the adhesive properties of reactive liquid rubber toughened epoxy-clay hybrid nanocomposites

Abstract The present work investigates the adhesive properties and morphology of diglycidyl ether of bisphenol A nanocomposites modified with reactive butadiene acrylonitrile copolymers having different amine equivalent weight. Tensile adhesive strength and shear adhesive strength of epoxy resin were significantly increased due to reactive rubbers and nanoparticles (ZW1) incorporation to the epoxy matrix. Hybrid composites based on 1 wt% ZW1 and 10 wt% ATBN-16, 1 wt% ZW1 and 15 wt% ATBN-21 exhibited maximum adhesive strength in comparison with neat epoxy resin as well as epoxy nanocomposite containing 1% ZW1. Tensile adhesive strength of hybrid composites containing 1% ZW1 and 10% ATBN-16 as well as 1% ZW1 and 15% ATBN-21 was maximally enhanced. The fracture surfaces of epoxy hybrid composites showed significant plastic yielding together with delaminated and stratified structures, explaining thus the increase of the adhesive strength of tested composites. This finding was confirmed by FTIR spectra in terms of chemical reactions occurrence between the reactive rubbers and epoxy matrix.

FROST-RESISTANT RUBBER ON BASE OF COMBINATION OF BUTADIENE-NITRILE AND HYDRIN RUBBERS

The influence of hydrin rubbers on the plastic-elastic, rheometric, physical-mechanical properties and frost resistance of oil-and-petrol resistant rubber mixture of B-14 type was studied. The study was carried out with the purpose of selecting the composition of the rubber mixture, which is resistant to low temperatures and has increased operational properties. The composition of the test rubber mixture with a sulfur vulcanization system consisted of butadiene-nitrile rubber BNKS-18AMN (copolymer of butadiene and acrylonitrile) and hydrin rubbers T-3000 and T-6000 (copolymers of epichlorohydrin, ethylene oxide, propylene oxide and allyl glycidyl ether), diphenylguanidine, zinc oxide, Agidol-2, technical carbon P 803, dibutyl sebacate and other ingredients. Rubber mixture was prepared by mixing caoutchoucs with ingredients on lab rolls LB 320 150/150. For the rubber mixture variants, the elastomeric properties on the viscosimeter MV 3000 and the vulcanization characteristics on the rheometer MDR 3000 of firm «Mon Tech» were investigated. The rubber mixture was vulcanized in a two-storey hydraulic electrically heated press VP-400-2E at a temperature of 150 °C for 40 min. Studies of the elastic-strength properties of rubber were carried out in accordance with the standards existing for the rubber industry. The frost resistance of rubber was investigated by determining the temperature limit of brittleness and by of method differential scanning calorimetry. The study of thermo-aggression resistance of vulcanizates was carried out by determining the change in their elastic-strength properties after prolonged thermal exposure to air and standard liquid SZHR-1, as well as changes in volume and mass after aging in technical oil AMG-10. As a result of the research it was established that the rubber mixture based on the combination of BNKS-18AMN and T-6000 rubbers can be used for the manufacture of frost-resistant rubber products and sealing elements for oil and gas industries that can work at elevated temperatures with improved elastic-strength and operational properties.Forcitation:Ushmarin N.F., Egorov E.N., Koltsov N.I. Frost-resistant rubber on base of combination of butadiene-nitrile and hydrin rubbers. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 60-64.

Poly(AN-co-PEGMA)/hBN/NaClO4 composite electrolytes for sodium ion battery

AbstractPolymer electrolytes composed of an acrylonitrile and polyethylene glycol methacrylate copolymer poly(AN-co-PEGMA) with addition of NaClO4 are studied by impedance spectroscopy, differential scanning calorimetry (DSC), fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Hexagonal boron nitride (hBN) particles are having increasing interest owing to mechanical properties, thermal stability, chemical stability and good lubrication property. In this study, hBN was used as an inorganic filler. FTIR spectroscopy was used to examine the interactions between the host polymer and both NaClO4 salt and nano hBN particles. The thermal properties of the composites were studied using TGA and DSC tests. TGA results showed that all the composites membranes were thermally stable till 300°C with one step degradation. Surface morphology of the films was examined with SEM which also reveals the homogeneous dispersion of nano hBN in the polymer matrix. Ionic conductivity was studied with impedance spectroscopy, the results showed that the ionic conductivity increases with increasing PEGMA ratio. ANcoPEGMA 11 20Na (EO:Na ratio=20) sample showed maximum ion conductivity of approximately 3.6×10−4 S cm−1 at 100°C. This is because ANcoPEGMA 11 20Na has highest percentage of PEGMA and highest number of Na+ ion per EO groups.

Rheological properties of bitumen emulsion modified with NBR latex

ABSTRACTNBR, a copolymer of butadiene and acrylonitrile, is used for applications requiring resistance to petroleum oils and gasoline. So using NBR as a modifier in bitumen, resistance against the destruction of gasoline and diesel oil will be increased. In this work, rheological properties of bitumen emulsion modified with NBR latex have been investigated. Bitumen emulsion samples were provided with various percent of NBR latex, and the residues of normal and modified bitumen emulsion were tested using ordinary and dynamic shear rheometer (DSR) methods. Using NBR latex as a modifier caused an increase in the softening point of bitumen emulsion residue as well as a decrease in the penetration grade and temperature sensitivity. At the end, by analyzing temperature sweep curves of DSR, it was found that modified bitumen emulsion residues with more than 6% NBR in residue have higher rutting potential temperatures.

Modification of polyacrylonitrile with ethylenedicarboxylic acid esters for preparing carbon fiber precursors

Specific features of copolymerization of acrylonitrile with dimethyl maleate and dimethyl fumarate under the action of a catalytic system based on copper(I) bromide and tris[(2-pyridyl)methyl]amine were studied. The polymerization occurs in the controlled mode, with the molecular weight of the copolymers increasing with conversion. The formation of the copolymers was proved by NMR spectroscopy. Introduction of the comonomers smooths the exothermic effect observed in oxidative stabilization of the polyacrylonitrile precursor.

Structural, morphological and thermal characterization of poly (2-hydroxyethyl methacrylate-co-acrylonitrile) (P (HEMA-co-AN)) Cryogels: evaluation of water sorption potential and cytotoxicity

Cryogels are macroporous hydrogels which are synthesized through cryogelation method. In the present study cryogels of poly (2-hydroxyethyl methacrylate-co-acrylonitrile) (P (HEMA-co-AN)) were synthesized by copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylonitrile (AN) monomers by redox polymerization using cryogelation technique. The synthesized cryogels were characterized by FTIR, SEM, XRD, DSC and TGA techniques. Different compositions of the cryogels were prepared by varying concentrations of the monomers and redox initiators in the feed mixture. These cryogels were then subjected to swelling studies and porosity determination. The swelling behavior was studied as function of concentration of the monomers, redox initiators, temperature, pH, and simulated biological fluids. The prepared cryogels were also characterized for their network parameters using water sorption data. The biocompatibility of P (HEMA-co-AN) cryogel was evaluated by in vitro cytotoxicity test. The results indicated that the P (HEMA-co-AN) cryogel had macroporous morphology and exhibited good water absorption capacity. Moreover, the cryogel was thermally stable and biocompatible in nature.

A Near-Infrared Light-Responsive Hybrid Hydrogel Based on UCST Triblock Copolymer and Gold Nanorods.

We report a near-infrared (NIR) light-responsive hydrogel that is capable of undergoing the gel to sol transition upon 785 nm light exposure based on a photothermal effect. The new hydrogel design relies on loading gold nanorods (AuNRs) in an ABA-type triblock copolymer, namely P(AAm–co–AN)–b–PDMA–b–P(AAm–co–AN), where P(AAm–co–AN) stands for a random copolymer of acrylamide and acrylonitrile that exhibits an upper critical solution temperature (UCST) in aqueous solution and PDMA is water-soluble polydimethylacrylamide. At solution temperature below UCST, the insoluble P(AAm–co–AN) blocks lead to formation of hydrogel of flower-like micelles. When the hydrogel is exposed to 785 nm NIR light, the absorption due to the longitudinal surface plasmon resonance of loaded AuNRs generates heat that raises the hydrogel temperature above UCST and, consequently, the gel-to-sol transition. The NIR light-triggered release of a protein loaded in the hydrogel was found to display a switchable fashion.

Preparation of fluorescent polyacrylonitrile nanofiber membrane based on polymerizable 1,8-naphthalimide fluorescent disperse dye

One new polymerizable fluorescent disperse dye (PEANI) based on 1,8-naphthalimide was synthesized via reaction of 2-(2-hydroxyethyl)-6-(1-pyrrolidinyl)-1H-benzo [de]isoquinoline-1,3(2H)-dione (PAENI) with acryloyl chloride firstly. Dye’s structure and fluorescent properties were carefully investigated using nuclear magnetic resonance (1H-NMR), UV-Vis and fluorescent spectra. Then the yellow copolymer (F-PAN) of PEANI and acrylonitrile was obtained through radical polymerization. Fluorescent nanofiber membrane could be prepared by electrospinning of the F-PAN solution in N,N-dimethylformamide solvent and strong green fluorescent emission located around 510 nm could be found (λex=450 nm). The electrospun F-PAN membrane showed obvious fluorescent effect even the mass ratio of PEANI to acrylonitrile was only 0.1 %, which has broken through the traditional limitation of using the cationic dye involved in the dyeing procedure to obtain fluorescent acrylic fabrics.

Preparation of hollow carbon submicro-fibers with controllable wall thicknesses from acrylonitrile copolymer

Most of the hollow carbon submicro-fibers (HCSFs) reported today are made from polyacrylonitrile (PAN) homopolymer. The obtained HCSFs are fragile due to the poor stabilization and spinnability of PAN. In this study, a bifunctional comonomer, β-methylhydrogen itaconate (MHI), was synthesized to prepare poly(acrylonitrile- co-β-methylhydrogen itaconate) [P(AN- co-MHI)] copolymer, which was used as a precursor to produce HCSF by coaxial electrospinning. The stabilization of P(AN- co-MHI) was studied by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR); the structure of HCSFs was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM). The stabilization of P(AN- co-MHI) has been improved significantly by MHI with lower cyclization temperature, broadened peak and lower activation energy, which is beneficial to producing high-performance HCSFs. HCSFs with fine and uniform structures were obtained after stabilization and carbonization; the diameter of the HCSFs shrinks due to the elimination of N and the extra H. The diameter and wall thickness of HCSFs can be controlled simply by the feeding ratio of P(AN- co-MHI) solution/styrene- co-acrylonitrile solution. The resultant HCSFs can be bent more than 280° without breaking, which has potential applications in lithium-ion rechargeable batteries, supercapacitors, fuel cells, and catalyst.