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ABSTRACT:The modification of a commercially available unsaturated polyester resin with 4,4Ј-bismaleimidodiphenylmethane is presented. The properties of the modified resins were compared with those of the nonmodified resin, and the resins were characterized in the noncured state and after curing. The results indicate that the addition of bismaleimide to unsaturated polyester resin not only improves its properties but also accelerates the curing reactions.

Highlights > A series of oxygen, nitrogen and phosphorus co-doped core-shell carbon sphere were developed. > The sample prepared at 800 °C with H 3 PO 4 activation showed the highest capacity and energy density. >The surface chemistry together with the well balanced porous structure of carbon electrode can greatly influence the electrochemical performance.

A novel method for synthesizing microspheres from lignin or lignin acrylate derivatives through copolymerization with styrene (St) and divinylbenzene (DVB) has been developed. The copolymers were obtained by the emulsion-suspension polymerization with a constant molar ratio of DVB to St of 1:1 (w/w) and different amounts of lignin or its derivatives. The morphologies of the obtained materials were examined by scanning electron microscopy. Two types of lignin modifications were performed to introduce vinyl groups into the lignin molecules: modification with acrylic acid and modification with epichlorohydrin plus acrylic acid. The course of modification was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy. The thermal stability and degradation behavior of the obtained microspheres were investigated by thermogravimetric analysis, and the pore structure was characterized via nitrogen sorption experiments. Owing to the presence of specific functional groups and the well-developed pore structure, the obtained Lignin-St-DVB microspheres may have potential application as specific sorbents for the removal of phenolic pollutants from water, as demonstrated by the solid-phase extraction technique.

Synthesis and properties of the multilayered stationary phases, which contain quaternary amine functional groups for the analysis of anions by ion chromatography, are described. The bonded phases were characterized by elemental analysis, solid-state (13)C NMR spectroscopy and chromatographic methods. The surface of 1,4-di(2-hydroxy-3-methacryloyloxypropoxy)phenol (solid support) was coated with polymeric layers formed by condensation polymerization of primary amine with diepoxide. Each layer of the anion exchange stationary phase consists of copolymer of methylamine (MA) and 1,4-butanedioldiglycidyl ether (BDDE). A series of stationary phases with different numbers of polymerized layers were tested. The separation of an inorganic anions sample (F(-), Cl(-), NO(2)(-), Br(-), NO(3)(-), additionally HPO(4)(2-) and SO(4)(2-)) was performed. In the measurement, a hydroxide, carbonate, bicarbonate and their mixture were used as mobile phases.

The CONTIN method for inverting noisy linear operators was used to calculate the adsorption distribution function from both simulated and experimental adsorption isotherms. Simulated isotherms allowed us to estimate the resolving power of the method and the influence of errors on the distribution function, while experimental isotherms enabled us to validate the adsorption model and its parameters. It was shown that calculation within the condensation approximation region gives perfect recovering of the original distribution if sufficient information is inherent in the input data, that is, in the case of a large data set over a wide range of relative pressures. When only a window of data is available on the adsorption isotherm, it is possible to calculate the distribution restricted to the condensation approximation (CA) region. The influence of peaks outside the CA region may be eliminated by introducing the constant background term in the calculation. The level of error on the isotherm does not affect the resulting distribution up to 10% in the case of a large data set and up to 5% in the case of a small data set. On the basis of analysis of the randomness of the residuals of the fit to the data, it was possible to establish a true parameter of the lateral interaction constant. This approach applied to experimental data has led to the value k 1 mob = 5.5−5.6 for the HdB mobile adsorption model and k 1 loc = 3 for the FG localized adsorption model. On the basis of the fact that optimal value of k 1 mob is closer to the theoretical value, the mobile adsorption model is preferred. The CONTIN method applied to graphitized carbon black revealed four peaks on the adsorption energy distribution function. The peak constrained analysis allowed us to confirm the existence of all original peaks. The distributions calculated from standard nitrogen adsorption data showed that although reference carbons are heterogeneous in different ways, they possess common peaks at 4.9, 6.8, and 8.8 kJ/mol characteristic to graphitized carbon black Sterling FT. Analysis of the heterogeneity of synthetic carbons revealed the changes in adsorption energy distributions (AEDs) that occur during CVD from methane.

The aim of this work was to prepare a new group of aromatic methacrylate monomers, utilise them in preparation of porous microspheres and study the influence of their chemical structure on the textural properties of porous methacrylate microspheres. Polymeric microspheres were prepared by suspension-emulsion polymerisation of four aromatic monomers: methacryloiloxybenzene, 1,2-dimethacryloiloxybenzene, 1,3-dimethacryloiloxybenzene and 1,4-dimethacryloiloxybenzene with another crosslinking agent-trimethylolpropane trimethacrylate. Mass median diameters of obtained beads are in the range 22-35 lm. The polymerisation reactions were carried out in the presence of a pore forming diluent. The influence of the diluent system on the porous structure of microspheres was studied in detail. To determine the textural properties of the studied microspheres, nitrogen adsorption-desorption and inverse sized exclusion chromatography measurements were used. Specific surface area of the obtained microspheres achieves value from 185 to 510 m 2 /g. Since obtained polymeric materials can be used as chromatographic packings for HPLC their porous structure in a swollen state was investigated. Significant differences in the porous structure parameters for dry and swollen microspheres were observed.