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.

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.

In this article the syntheses of dimethacrylate and trimethacrylate esters as well as the mechanical and thermal properties of their copolymers with methyl methacrylate and styrene are investigated. The esters were obtained from acidic derivatives of nadic anhydride and glycidyl methacrylate. The addition reaction of glycidyl methacrylate and the acidic compound was carried out in the presence of basic catalyst-tetraethylammonium bromide. The monomers and resins were UV cured in the presence of a suitable photoinitiator which was 2,2-dimethoxy-2-phenyloacetophenone. The prepared polymers were subjected to different studies concerning evaluation of their mechanical properties, thermal stability, dynamic mechanical behavior (DMA) as well as the estimation of the content of unreacted double bonds in the final product. The results proved their good thermal and mechanical properties. The degree of unsaturated bonds conversion was found to be growing with the amount of monovinyl monomer in the copolymer. Trimethacrylatebased copolymers are characterized by a greater content of double bonds present in the obtained material compared to that of dimethacrylate-based copolymers. As indicated by DMA the network structures of the copolymers seem to be more heterogeneous with the increasing weight fraction of trimethacrylate as well as dimethacrylate monomer.

Synthesis and properties of epoxyfumarate and epoxymaleate resins obtained by the addition of acidic benzyl maleate to the commercially available epoxy resin are presented. The resins were synthesized in one-and two-step procedures. In the two-step procedure, acidic benzyl maleate was synthesized separately and then used for the addition reaction with epoxy resin, Epidian 5. In the one-step procedure, acidic ester was formed during the synthesis process. Properties of the resins in a noncrosslinked state, during curing, and after crosslinking were compared.

Dimethyldichlorosilane has been used to deactivate the hydroxyl groups present in the skeleton of the porous polymer formed from the methacrylic ester of p,p'-dihydroxydiphenylmethane diglycidyl ether and divinylbenzene. The influence of chemical modification of the copolymer on its chromatographic behavior has been studied. The retention indices of five homologous series and test compounds were calculated to determine the selectivity of the packings.

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In this work, the synthesis as well as the mechanical and thermal properties of dimethacrylate copolymers are investigated. These copolymers were obtained from glycidyl methacrylate, maleic and/or fumaric acid adducts, methyl methacrylate, and/or styrene. The addition reaction of glycidyl methacrylate as well as maleic and fumaric acids was carried out in the presence of basic catalyst.

Syntheses of epoxy-based divinyl ester resin and its modification with toluene diisocyanate (TDI) are presented. The resin was obtained from commercially available epoxy resin Epidian 5 and methacrylic acid during graduated heating. Three different resin solutions were obtained by adding 45, 50, and 55% of styrene; then, each solution was modified with TDI at room temperature. Properties of the resins before and after modification were studied.