No abstract available

[en] 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. (paper)

[en] The macroporous synthetic poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogels as 3D cellular scaffolds with specific internal morphology, so called dual pore size, were designed and studied. The morphological microstructure of hydrogels was characterized in the gel swollen state and the susceptibility of gels for stem cells was evaluated. The effect of specific chemical groups covalently bound in the hydrogel network by copolymerization on cell adhesion and growth, followed by effect of laminin coating were investigated. The evaluated gels contained either carboxyl groups of the methacrylic acid or quaternary ammonium groups brought by polymerizable ammonium salt or their combinations. The morphology of swollen gel was visualized using the laser scanning confocal microscopy. All hydrogels had very similar porous structures – their matrices contained large pores (up to 10² μm) surrounded with gel walls with small pores (10⁰ μm). The total pore volume in hydrogels swollen in buffer solution ranged between 69 and 86 vol%. Prior to the seeding of the mouse embryonal stem cells, the gels were coated with laminin. The hydrogel with quaternary ammonium groups (with or without laminin) stimulated the cell growth the most. The laminin coating lead to a significant and quaternary ammonium groups. The gel chemical modification influenced also the topology of cell coverage that ranged from individual cell clusters to well dispersed multi cellular structures. Findings in this study point out the laser scanning confocal microscopy as an irreplaceable method for a precise and quick assessment of the hydrogel morphology. In addition, these findings help to optimize the chemical composition of the hydrogel scaffold through the combination of chemical and biological factors leading to intensive cell attachment and proliferation. (paper)

[en] The morphological changes in giant vesicles were investigated using mixed amphiphilic diblock copolymers consisting of poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid), PMAA-b-P(MMA-r-MAA). The mixed copolymers had the identical length of the hydrophobic P(MMA-r-MAA) block and different lengths of the hydrophilic PMAA block; long-length PMAA (PMAA-L) was about three times longer than short-length PMAA (PMAA-S). Large contorted vesicles formed by the copolymer containing PMAA-S were transformed into various elliptical and spherical vesicles, followed by worm-like vesicles as the ratio of the PMAA-L-containing copolymer increased. It was found that the vesicular morphology of the mixed copolymers was determined by the average length of the PMAA blocks contained in the mixed copolymers based on the comparison with the spherical vesicles formed only by the copolymer containing the middle length of the PMAA block.

[en] Poly(methacrylic acid-co-2-aminoethyl methacrylate) (MAA-AMA) was simply synthesized by free radical polymerization. Immobilization of 2,4-dihydroxybenzaldehyde on MAA-AMA was done via Schiff base formation to obtain MAA-AMA(BZ). The qualitative and quantitative analyses of immobilization were done by nuclear magnetic resonance spectroscopy. The degree of immobilization of 2,4-dihydroxybenzaldehyde on MAA-AMA was 16–18%. Surface charge and particle size of MAA-AMA(BZ) is pH sensitive. In addition, intermolecular amidation provided cross-link structure at pH 12. The MAA-AMA(BZ) acted as an antifungal against Aspergillus genus with a percentage efficiency up to 25% against A. fumigatus.

[en] Flow synthesis of poly(methyl methacrylate) particles was performed by heterogeneous polymerization of methyl methacrylate using a water-in-oil (W/O) slug flow with or without a non-ionic surfactant in the continuous organic phase. It was found that undesired phenomena in this polymerization system, clogging of the channel and broadening particle size distribution, can occur when growing polymer particles adsorb to the W/O interface during polymerization, and that the addition of non-ionic surfactant to the continuous organic phase prevents the particles from adsorption to the W/O interface and gives monodisperse polymer particles. In addition, it was shown that as the initiator concentration increases, the particle diameter becomes larger, resulting in monodisperse micron-sized polymer particles with 100% monomer conversion at a 120-min reaction time. These results indicated that the heterogeneous polymerization process using a W/O slug flow can be a promising way to continuously prepare monodisperse polymer particles with micron sizes in a short reaction time.

[en] Poly-(methyl methacrylate-co-benzyl methacrylate) polarization-maintaining optical fibers are known for their high response to normal stress. In this report, responses to higher stress levels up to 0.45 MPa were investigated. The stress amplitude and direction in the fiber cross section were calculated and analyzed with a coincident mode-field obtained from the near-field pattern. The stress amplitude varies significantly in the horizontal direction and is considered to create multiple phases, explaining the measurement results. To investigate possible permanent deformation, the core yield point profile was analyzed. Although it largely exceeds the average applied stress, the calculated stress distribution indicates that the core could partially experience stress that exceeds the yield point

[en] It is essential to control polymerization parameters in order to reach a specific polymer. A fuzzy controller is proposed to control temperature using reactor and jacket deviations. However, uncertainty exists on a jacket temperature, due to noise disturbance effects. Fuzzy numbers are applied to model this uncertainty. Consequently, a fuzzy trajectory is derived for jacket temperature. Finally, a pseudo-Sugeno fuzzy controller is designed for temperature tracking. The results show the good performance of this controller for control of solution polymerization of methyl methacrylate

[en] Plastic scintillators (PS) were made based on benzyl methacrylate and methyl-methacrylate P(BzMA + MMA) copolymer in which the excimer forming rate is by two order lesser than that in polystyrene-based polymer matrix. Studying of these PS light yield demonstrates the importance of migration processes comparing to excimer formation. It is found that to obtain PS with high scintillation efficiency it is necessary to use the polymer base (matrix) in which excimer forming is eliminated but the migration process along the chromophores is maximally favored. To explain the accelerated energy transfer between phenyl chromophores it is proposed to use a mechanism of exchange of that virtual excitons that can propagate along a one-dimensional back-bone of polymer molecule. Clearing the details of mechanism of interaction between chromophores of polymer molecules which is responsible for accelerated radiationless energy transfer enable will determine in future the way of effective plastic scintillators designing.

[en] The invention concerns a process where the monomers in prepolymerised form are included in a resin, which is further transformed into a resin which can be hardened by irradiation. These resins are suitable as coverings, printing ink carriers, strengthened plastic articles etc. The process provides for: a) The presence of a poly-epoxide with more than a 1.2 oxyran group per molecule, a mixture of a vinyl acid and a mono vinyl monomer to be polymerised and b) that the product obtained in stage a) is converted using an unsaturated monocarbon acid. 9 examples explain details of the invention. (UWI)