Butyl Methacrylate Copolymers Research Articles

Poly(Sitosterol)‐Based Hydrophobic Blocks in Amphiphilic Block Copolymers for the Assembly of Hybrid Vesicles

AbstractAmphiphilic block copolymer and lipids can be assembled into hybrid vesicles (HVs), which are an alternative to liposomes and polymersomes. Block copolymers that have either poly(sitostryl methacrylate) or statistical copolymers of sitosteryl methacrylate and butyl methacrylate as the hydrophobic part and a poly(carboxyethyl acrylate) hydrophilic segment are synthesized and characterized. These block copolymers assemble into small HVs with soybean L‐α‐phosphatidylcholine (soyPC), confirmed by electron microscopy and small‐angle X‐ray scattering. The membrane's hybrid nature is illustrated by fluorescence resonance energy transfer between labeled building blocks. The membrane packing, derived from spectra when using Laurdan as an environmentally sensitive fluorescent probe, is comparable between small HVs and the corresponding liposomes with molecular sitosterol, although the former show indications of transmembrane asymmetry. Giant HVs with homogenous distribution of the block copolymers and soyPC in their membranes are assembled using the electroformation method. The lateral diffusion of both building blocks is slowed down in giant HVs with higher block copolymer content, but their permeability toward (6)‐carboxy‐X‐rhodamine is higher compared to giant vesicles made of soyPC and molecular sitosterol. This fundamental effort contributes to the rapidly expanding understanding of the integration of natural membrane constituents with designed synthetic compounds to form hybrid membranes.

Composition Dependency of the Flory-Huggins Interaction Parameter in Drug-Polymer Phase Behavior.

An innovative strategy to address recent challenges in the oral administration of poorly soluble drugs is the formulation of amorphous solid dispersions (ASDs), where the drug is dissolved in a highly soluble carrier polymer. Therefore, special knowledge of the drug-polymer phase behavior is essential for an effective product and process design, accelerating the introduction of novel efficacious ASD products. Flory-Huggins theory can be applied to model solubility temperatures of crystalline drugs in carrier polymers over the drug fraction. However, predicted solubility temperatures lack accuracy in cases of strong drug/polymer interactions that are not represented in the Flory-Huggins lattice model. Within this study, a modeling strategy is proposed to improve the predictive power through an extension of the Flory-Huggins interaction parameter by a correlation with the drug fraction. Therefore, the composition dependency of the Flory-Huggins interaction parameter was evaluated experimentally for various drug-polymer formulations that cover a wide variety of drug and polymer characteristics regarding molecular weights, glass transition temperatures and melting temperatures, as well as drug-polymer interactions of different strengths and effects. The extended model was successfully approved for nine exemplary ASD formulations containing the drugs acetaminophen, itraconazole, and griseofulvine, as well as the following polymers: basic butylated methacrylate copolymer, Soluplus®, and vinylpyrrolidone/vinyl acetate copolymer. A high correlation between the predicted solubility temperatures and experimental and literature data was found, particularly at low drug fractions, since the model accounts for composition dependent drug-polymer interactions.

Investigation of the degradation and in-situ amorphization of the enantiomeric drug escitalopram oxalate during Fused Deposition Modeling (FDM) 3D printing

Hot-melt extrusion (HME) and subsequent FDM 3D printing offer great potential opportunities in the formulation development and production of customized oral dosage forms with poorly soluble drugs. However, thermal stress within these processes can be challenging for thermo-sensitive drugs. In this work, three different formulations were prepared to investigate the degradation and the solid state of the thermo-sensitive and poorly soluble drug escitalopram oxalate (ESC-OX) during the two heat-intensive processes HME and FDM 3D printing. For this purpose, hydroxypropyl methyl cellulose (HPMC) and basic butylated methacrylate copolymer (bPMMA) were chosen as polymers. DSC and XRD measurements revealed that ESC-OX is amorphous in the HPMC based formulations in both, extrudates and 3D printed tablets. In contrast, in-situ amorphization of the drug from crystalline state in bPMMA filaments was observed during FDM 3D printing. With regard to the content, it was found that degradation of ESC-OX in extrudates with bPMMA could be avoided and in 3D printed tablets almost fully reduced. Furthermore, a possible conversion into the R-enantiomer in the formulation with bPMMA could be excluded using a chiral column. Compared to the commercial product Cipralex®, drug release from extrudates and tablets with bPMMA was slower but still qualified as immediate drug release.

Application of a three-fluid nozzle for the preparation of amorphous solid dispersions

In this work, the manufacture of amorphous solid dispersions of poorly water-soluble carbamazepine using a laboratory spray drying setup with a three-fluid nozzle and two separate liquid feed solutions of (a) the active and (b) the polymeric excipient (copovidone or basic butylated methacrylate copolymer) was investigated and compared to a traditional two-fluid nozzle setup. Results show that particles with the desired drug content were manufactured using the three-fluid nozzle setup. Amorphous solid dispersion could be obtained up to a drug load of 50% (w/w) processing solutions with miscible solvents and copovidone as polymer. Higher active concentrations, the use of immiscible solvents or switching of the capillaries led to a substantial crystallization of carbamazepine as seen in XRD and DSC analysis. The polymorphic form IV of carbamazepine was formed in the presence of copovidone at high solid concentrations of the liquid feed.

Composition-Property Relationships of pH-Responsive Poly[(2-vinylpyridine)-co-(butyl methacrylate)] Copolymers for Reverse Enteric Coatings.

The taste-masking of bitter-tasting active pharmaceutical ingredients is key to ensuring patient compliance when producing oral pharmaceutical formulations. This is generally achieved via the incorporation of pH-responsive, reverse enteric polymers, that prevent the dissolution of the formulation in the oral environment, but rapidly mediate it within the gastric environment. Reverse enteric polymers are commonly applied as coatings on oral dosage forms via spray atomisation (e.g., fluidised-bed spray coating), and generally exhibit the most efficient taste-masking. However, currently used reverse enteric coatings require high mass gains (% w/w) during coating to mediate taste-masking, and thereby exhibit delayed release within the gastric environment. Therefore, there remains a need for the development of new reverse enteric coatings, that can efficiently taste-mask at low mass gains and maintain rapid release characteristics within the gastric environment. Herein we report the synthesis and evaluation of a series of addition copolymers of 2-vinylpyridine and butyl methacrylate, methyl methacrylate and isobornyl methacrylate. The thermal, solubility, and water absorption properties of the copolymers were effectively tuned by altering the mol% fraction of the constitutive monomers. Based on their physical properties, selected copolymers were preliminarily evaluated for their compatibility with fluidised-bed spray coating, and effectiveness as taste-masking reverse enteric coatings. The copolymers poly[(2-vinylpyridine)-co-(butyl methacrylate)] (mol% ratio 40:60) and poly[(2-vinylpyridine)-co-(butyl methacrylate)-co-(methyl methacrylate)] (mol% ratio 40:50:10) were found to exhibit excellent taste-masking properties following fluidised-bed spray coating onto Suglets® sugar spheres. Suglets® bearing a film coating of either copolymer (5.2-6.5% w/w mass gain) were found to effectively impede the release of a model drug formulation for up to 72 h in a simulated salivary environment, and rapidly release it (<10 min) within a simulated gastric environment. The results demonstrated the potential of poly[(2-vinylpyridine)-co-(butyl methacrylate)] copolymers to form effectively taste-masked, reverse enteric dosage forms, and suggested that these copolymers may provide improved performance compared to currently available polymers.

Membrane composition of polymer-lipid hybrid vesicles

Hybrid vesicles (HVs) assembled from phospholipids and amphiphilic block copolymers (BCPs) are a more recent alternative to liposomes and polymersomes. We aim to change the properties of the HV membranes by varying the chemical composition of the hydrophobic block in the BCPs that have poly(carboxyethyl acrylate) (PCEA) as the hydrophilic part. To this end, statistical copolymers of cholesteryl methacrylate and either butyl methacrylate (BuMA) or 2-hydroxyethyl methacrylate (HEMA) as well as the corresponding homopolymers were synthesized and used as macroinitiator for the extension with PCEA. All the BCPs allowed for the assembly of small and giant HVs with soybean L-α-phosphatidylcholine. The extend of the co-extisting micellar populations varied as shown by transmission electron microscopy and small-angle X-ray spectroscopy. Although the membrane packings derived from spectra when using Laurdan as an environmentally sensitive fluorescent probe were comparable between the different HVs, their permeability towards 5(6)-carboxy-X-rhodamine or carboxyfluorescein depended on the membrane composition, i.e., HEMA-containing membranes had higher permeability than membranes containing the other tested BCPs for small and giant HVs. Further, membranes with BuMA offered the most suitable environment for the association with β-galactosidase illustrated by the efficient substrate conversion. Taken together, the hydrophobic block is a relevant mean to control the morphologies and membrane properties of HVs.

Precise Dosing of Pramipexole for Low-Dosed Filament Production by Hot Melt Extrusion Applying Various Feeding Methods.

The aim of this research was the production of low-dosed filaments via hot-melt extrusion (HME) with the model drug pramipexole for the treatment of Parkinson’s disease. The active pharmaceutical ingredient (API) and one of the polymers polyvinyl alcohol (PVA) or basic butylated methacrylate copolymer (bPMMA) were fed by various dosing techniques with the aim of achieving the smallest deviation (RSD) from the target concentration of 0.1% (w/w) pramipexole. It was found that deviation from target pramipexole concentration occurred due to degradation products in bPMMA formulations. Additionally, material temperature above 120 °C led to the formation of the anhydrous form of pramipexole within the extruded filaments and need to be considered in the calculation of the recovered API. This study clearly shows that even if equilibrium state of the extrusion parameters was reached, equilibrium condition for drug content was reached relatively late in the process. In addition, the RSD calculated by the Stange–Poole equation was proposed by us to predict the final content uniformity considering the sample size of the analyzed filament. The calculated RSD, depending on sample size and drug load, can serve as upper and lower limits of variation from target concentration and can be used to evaluate the deviations of drug content in equilibrium conditions of the HME process. The lowest deviations from target concentration in equilibrium condition for drug content were obtained in filaments extruded from previously prepared granule mixtures (RSD = 6.00%, acceptance value = 12.2). These promising results can be transferred to other API–excipient combinations to produce low-dosed filaments, which can be used for, e.g., fused filament 3D printing. The introduced calculation of the RSD by Stange–Poole equation can be used for precise determination of the homogeneity of an extruded batch.

Nonionic Polymer with Flat Upper Critical Solution Temperature Behavior in Water.

We rationally designed a monomer that when polymerized formed a well-defined nonionic polymer [poly(2-(methacryloyloxy) ethylureido glycinamide), PMEGA] by reversible addition fragmentation chain transfer with a flat and tunable upper critical solution temperature (UCST) in water. The monomer was made in one pot from commercially available compounds and with ease of purification. Strong hydrogen-bonding side groups on the polymer produced sharp coil-to-globule transitions upon cooling below its UCST. Ideal random copolymers produced with butyl methacrylate also showed flat UCST profiles, in which the UCST increased with a greater butyl methacrylate copolymer composition from 7 to 65 °C. In the presence of NaCl, the UCST decreased linearly with NaCl concentration due to the "salting-in" effect, and it was found that the slopes from the linear decrease of UCST were nearly identical for all copolymer compositions. This new polymer and its copolymers support the hypothesis that strong hydrogen bonding between the side groups allowed the flat UCST to be readily tuned with a high level of predictability. We postulate that this polymer system may provide wide biological applicability similar to that found for the well-used flat lower critical solution temperature (LCST) of poly(N-isopropylacrylamide).

Development of immediate release 3D-printed dosage forms for a poorly water-soluble drug by fused deposition modeling: Study of morphology, solid state and dissolution

3D-printing technologies such as Fused Deposition Modeling (FDM) bring a unique opportunity for personalized and flexible near-patient production of pharmaceuticals, potentially improving safety and efficacy for some medications. However, FDM-printed tablets often exhibit tendency for slow dissolution due to polymer erosion-based dissolution mechanisms. Development of immediate release (IR) 3D-printed dosage with poorly water-soluble compounds is even more challenging but necessary to ensure wide applicability of the technology within pharmaceutical development portfolios. In this work, process and morphology were considered to achieve IR of BCS class IV compound lumefantrine as model active pharmaceutical ingredient (API) using basic butylated methacrylate copolymer (Eudragit EPO) as matrix former, as well as hydrophilic plasticizer xylitol and pore former maltodextrin. Grid-designed tablets with size acceptable for children from 6 years old and varying programmed infill density were successfully 3D-printed with 5% lumefantrine while higher drug load led to increased brittleness which is incompatible with 3D-printing. Lumefantrine assay was 92 to 97.5% of theoretical content depending on drug load and process parameters. 3D-printed tablets with 65% infill density met rapid release criteria, while 80% and 100% showed slower dissolution. Structural characteristics of 3D-printed tablets with non-continuous surface such as accessible porosity and specific surface area by weight and by volume were quantified by a non-destructive automated µCT-based methodology and were found to correlate with dissolution rate. Increase in accessible porosity, total surface area, specific surface area and decrease in relative density were statistically significant critical factors for modification of lumefantrine dissolution rate. Crystallinity in manufactured tablets and filaments was explored by highly sensitive Raman mapping technique. Lumefantrine was present in the fully amorphous state in the tablets exhibiting adequate stability for on-site manufacturing. The study demonstrates feasibility of immediate release FDM-3D-printed tablets with BCS class IV API and illustrates the correlation of FDM design parameters with morphological and dissolution characteristics of manufactured tablets.

Tunable polymer dye laser pumped by two 513 nm diodes

We demonstrate a tunable solid-state polymer dye laser with quasi-longitudinal pumping by two green (λ = 513 nm) laser diodes. Tuning curves with a maximum efficiency of 13% were attained, using a plate of crystalline quartz (Lyot filter) for wavelength selection. In a three-mirror cavity with partial compensation of astigmatism, the total tuning range was 62 nm (from 545 nm to 607 nm) for pyrromethene dyes: PM567, PM580 and PM597. The best results were achieved with active elements based on Pyrromethene 580 laser dye in a mixture of polyvinyl butyral or a copolymer of butylmethacrylate and methacrylic acid (ratio 9:1) with the addition of 30% dibutylsebacinate as a plasticizer.

Research of strength and conducting properties of composite material modified by carbon nanotubes

The article studies the fabrication mechanism of semiconducting composite polymer material based on methyl methacrylate, butyl methacrylate and methacrylic acid co-polymer doped with carbon nanotubes (CNT). A mechanism for fabrication of composite polymer material modified with carbon nanotubes has been developed, and experimental studies of the strength, electrical and physical characteristics of the materials obtained have been carried out.

Carrageenans from Sarcothalia crispata and Gigartina skottsbergii: Structural Analysis and Interpolyelectrolyte Complex Formation for Drug Controlled Release.

The aims of the present study were to characterize for the first time the carrageenan extracted from cystocarpic stage of S. crispata collected in the Patagonian coast of Argentina, and to prepare interpolyelectrolytic complexes (IPECs) between the polysaccharide extracted from cystocarpic stage of Sarcothalia crispata and Gigartina skottsbergii thalli, and basic butylated methacrylate copolymer (Eudragit E), in order to test their potential for the controlled release of ibuprofen as model drug. The structural determination revealed that the polysaccharides extracted from S. crispata and G. skottsbergii were mainly constituted by κ-carrageenan, particularly in the case of G. skottsbergii; however, significant amounts of ι- and ν-carrageenan were also detected in both polygalactans. The differences in diad composition and possibly in their distribution along the polysaccharide chain of both carrageenans would favor a different arrangement in the resulting IPEC structure. The smaller pores observed by scanning electron microscopy in the IPEC of S. crispata suggest that the kinks in the polysaccharide backbone are evenly distributed, resulting in a slower ibuprofen release compared to the IPEC of G. skottsbergii.

Spheroid Formation of Human Adipose-Derived Stem Cells on Environmentally Friendly BMA/SBMA/HEMA Copolymer-Coated Anti-Adhesive Surface

Abstract Surface coating with sulfobetaine methacrylate (SBMA) containing polymers is a simple method for reducing non-specific protein adsorption and cell adhesion to biomaterials. It has been shown that copolymers of zwitterionic monomers and butyl methacrylate (BMA) could be adsorbed onto hydrophobic substrates in order to provide anti-fouling properties. However, the copolymers of BMA/SBMA dissolved in organic solvents such as DMSO and THF, which is harmful to the host and environment, but not in environmentally friendly solvents, such as methanol and ethanol. Hydroxyethyl methacrylate (HEMA) was introduced in the copolymers in order to enhance the solubility of BMA/SBMA copolymers in methanol and ethanol. The solubility of the copolymers in methanol, ethanol and DMSO were examined. BMA/SBMA/HEMA copolymers in different solvents were coated on polystyrene (PS) plates, and the surface hydrophilicity and anti-fouling capacity were investigated. On the other hand, many studies have pointed out that spheroid formations of stem cells have the abilities to boost functionality and enhance their therapeutic potential. Therefore, the spheroid formation of human adipose-derived stem cells (hASCs) was studied on a plate coated with copolymers. The substrates coated with the copolymers prevented the adhesion of human adipose-derived stem cells (hASCs); moreover, hASCs formed spheroids after 24 hours of culture. In conclusion, the addition of HEMA in the BMA/SBMA copolymers made the copolymers soluble in methanol and ethanol. With the coating of copolymers, cell adhesion was inhibited and the stem cell spheroids were formed on the plate. The copolymers showed a potential for surface modification under an environmentally friendly condition for anti-fouling and stem cell spheroid application.

Engineering Synergistically Active and Bioavailable Cost-effective Medicines for Neglected Tropical Diseases; The Role of Excipients.

Leishmaniasis is a neglected tropical disease responsible for the ninth largest disease burden in the world threatening 350 million people mostly in developing countries. The lack of efficacy, severe adverse effects, long duration, high cost and parenteral administration of the current therapies result in poor patient compliance and emergence of resistance. Leishmaniasis' unmet need for safer, affordable and more effective treatments is only partly addressed by today's global health product pipeline that focuses on products amenable to rapid clinical development, mainly by reformulating or repurposing existing drugs for new uses. Excipients are necessary for ensuring the stability and bioavailability of currently available antileishmaniasis drugs which in their majority are poorly soluble or have severe side-effects. Thus, selection of excipients that can ensure bioavailability and safety as well as elicit a synergistic effect against the Leishmania parasites without compromising safety will result in a more efficacious, safe and fast to market medicine. We have evaluated the in vitro activity of 30 commercially available generally regarded as safe (GRAS) excipients against different Leishmania spp., their cytotoxicity and potential use for inclusion in novel formulations. Amongst the tested excipients, the compounds with higher selectivity index were Eudragit E100 (cationic triblock copolymer of dimethylaminoethyl methacrylate, butyl methacrylate, and methyl methacrylate), CTAB (cetyltrimethylammonium bromide, cationic), lauric acid, Labrasol(non-ionic, caprylocaproyl polyoxyl- 8 glycerides) and sodium deoxycholate. An ideal excipient need to possess amphiphilic nature with ionic/polar groups and possess a short or medium fatty acid chain such as lauric (C12), capric C10) or caprylicacid (C8). Inclusion of these excipients and identification of the optimal combination of drug and excipients would lead to a more effective and safer antileishmanial therapies.

Poly(ethylene-co-BMA) via dual concurrent ATRP–RAFT and its thermokinetic study

Well-defined copolymers of ethylene and butyl methacrylate (BMA) (poly(ethylene-co-BMA)) with narrow molecular weight distribution were synthesized via dual concurrent atom transfer radical polymerization (ATRP) and reversible addition–fragmentation chain transfer (RAFT) polymerization using 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid as an alkyl pseudo-halide initiator, ascorbic acid/FeCl3/2,2′ bipyridine as the ATRP catalyst system and ethyl-2-bromo-isobutyrate as co-initiator in N, N′-dimethyl formamide at 100 °C. From size exclusion chromatography result, controlled molecular weight with narrow molecular weight distributions of poly(ethylene-co-BMA) was obtained in every case. The experimental results indicated that dual concurrent ATRP–RAFT polymerization is more successful over free radical or RAFT polymerization in terms of controlling molecular weight and polydispersity. X-ray diffraction analysis demonstrated the amorphous behaviour of poly(ethylene-co-BMA) while thermogravimetric analysis reveals that the main decomposition of poly(ethylene-co-BMA) occurs in the range 300–420 °C. The multivariate nonlinear regression analysis was performed to establish the mechanism and kinetic model and found that n-dimensional Avrami–Erofeev (An) mechanism was responsible for the decomposition of the synthesized poly(ethylene-co-BMA). The apparent activation energy (E a) of decomposition of the synthesized copolymer was found to be 211.88 kJ mol−1.

Sorption of Benzene, Dichloromethane, and 2-Butanone by Poly(methyl methacrylate), Poly(butyl methacrylate), and Their Copolymers at 323.15 K Using a Quartz Crystal Balance

Isothermal solubilities at 323.15 K of benzene, dichloromethane, and 2-butanone in poly(methyl methacrylate), poly(butyl methacrylate), and two different poly(methyl methacrylate)-poly(butyl methacrylate) copolymers are reported. Results were obtained for the concentrated polymer regime with a quartz crystal balance and are represented to within experimental error by a modified Flory–Huggins equation.

Design and evaluation of acrylate polymeric carriers for fabrication of pH-sensitive microparticles

Colon-targeted microparticles loaded with a model anti-inflammatory drug were fabricated using especially designed acrylic acid–butyl methacrylate copolymers. Microparticles were prepared by oil-in-oil solvent evaporation method using Span 80 as emulsifier. Microparticles were found to be spherical in shape, hemocompatible and anionic with zeta potential of −27.4 and −29.0 mV. Entrapment of drug in the microparticles was confirmed by Fourier transform infrared (FTIR) spectroscopy. However, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) revealed amorphous nature of microparticles due to the dilution effect of amorphous polymer. The microparticles released less than 5% drug at pH 1.2, while more than 90% of the drug load was released at pH 7.4. This suggested the colon targeting nature of the formulations. In experimentally developed colitis in Wistar rats, the microparticle formulation showed significant reduction (p < .05) in the disease activity score (disease symptoms), the colon-to-body weight ratio (tissue edema) and the myeloperoxidase, tumor necrosis factor (TNF)-α and interleukin (IL)-1β activities.

Intra‐ and inter‐supramolecular complexation of poly(butyl methacrylate)‐co‐2‐(1,2,3‐triazol‐4‐yl)pyridine copolymers induced by CoII, FeII, and EuIII ions monitored by molecular hydrodynamics methods

ABSTRACTPoly(butyl methacrylate) copolymers embedding bidentate 2‐(1,2,3‐triazol‐4‐yl)pyridine (trzpy) chelating units as comonomer in the side chains were synthesized by controlled radical addition‐fragmentation transfer (RAFT) polymerization. Intracomplexation and intercomplexation of the macromolecules of the poly(butyl methacrylate) copolymers containing 20 % mol of trzpy units induced by CoII, FeII, and EuIII ions were studied in the solutions by macromolecular hydrodynamics methods. The sedimentation velocity of extremely diluted copolymer solutions and the dynamic viscosity of moderately diluted solutions were studied in a wide range of the salts concentrations. Differences were observed with respect to the copolymer behavior in the presence of the Co2+, Fe2+, Eu3+ ions. These differences are namely due to the differences in the number of coordination bonds required for complex formation and not explicitly to the nature of the corresponding anions. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2632–2639

Electrospun polyvinyl chloride/poly (butyl methacrylate-co-butyl acrylate) fibrous mat for absorption of organic matters

Polyvinyl chloride (PVC) is a hydrophobic and lipophilic polymer, and its electrospun mat has plenty of micro- and nanopores. However, the PVC electrospun mat cannot absorb organic substances due to its weak fiber-web structure. The copolymer of butyl methacrylate (BMA) and butyl acrylate (BA) has very good electrospinnability, and its electrospun fibers can construct a firm fiber-web structure through many bonded nodes. However, there are few micro- and nanopores in the fiber-web of the copolymer of BMA and BA since the electrospun fibers of the copolymer of BMA and BA can cohere with each other. Therefore, the copolymer of BMA and BA was blended with PVC in N,N-dimethylformamide to provide their electrospun fibrous mat with good fiber-web structure and many micro- and nanopores, and their electrospun fibrous mat was then used as an absorbent of organic substances in this work. We first discovered the electrospinnable concentrations for PVC solution, the solution of the copolymer of BMA and BA, and the blend solution of PVC and the copolymer of BMA and BA by researching the characteristics of these solutions, and we analyzed the effect of the electrospinnability of PVC in the blend solution on the formation of fiber-web structure. Then, the blend solution with an electrospinnable concentration was electrospun into fibrous mat, and its surface characteristics and absorption capability to organic matters were subsequently investigated. The correlation between absorption capability and fiber-web structure was analyzed through field emission scanning electron microscope. The result showed that the blend solution of PVC and the copolymer of BMA and BA had better electrospinnability in comparison with PVC solution, and the corresponding fibrous mat had a great potential application in removing organic matters since it owned better hydrophobic and lipophilic properties than the fibrous mat electrospun from PVC solution or the solution of the copolymer of BMA and BA.

Magnetoimpedance of cobalt-based amorphous ribbons/polymer composites

The combined influence of the temperature, the elastic tensile stress and the external magnetic field on the total impedance and impedance components were studied for rapidly quenched amorphous Co75Fe5Si4B16 ribbons. Both as-cast amorphous ribbons and Co75Fe5Si4B16/polymer amorphous ribbon based composites were considered. Following polymer coverings were studied: modified rubber solution in o-xylene, solution of butyl methacrylate and methacrylic acid copolymer in isopropanol and solution of polymethylphenylsiloxane resin in toluene. All selected composites showed very good adhesion of the coverings and allowed to provide temperature measurements from 163K up to 383K under the applied deforming tensile force up to 30N. The dependence of the modulus of the impedance and its components on the external magnetic field was influenced by the elastic tensile stresses and was affected by the temperature of the samples. It was shown that maximal sensitivity of the impedance and its components to the external magnetic field was observed at minimal temperature and maximal deforming force depended on the frequency of an alternating current.