Properties of Absorbent Acrylic Foam Prepared Based on the Method of High Internal Phase Emulsion

Acrylate and methacrylate monomers absorbent acrylate foams were prepared based on the method of high internal phase emulsion (HIPE). The influence of reaction conditions on liquid absorption by acrylate foams was studied. The reaction conditions included monomer ratio, cross-linker amount, initiator amount, emulsifier amount, emulsion concentration, emulsification temperature, and the curing time. The reaction conditions were determined to achieve the best liquid absorption by acrylate foams. Acrylate foams were analyzed with Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that when the monomer ratio was 9:1, cross-linking agent was 30% of monomer amount, initiator amount was 4% of the reactants amount, emulsifier amount was 8% of the reactants amount, the ratio of aqueous phase to oil phase was 32:1, emulsification temperature was 75°C, and curing time was 1.5 h, we could prepare the acrylate foam material with the best liquid absorption. Reaction of monomer and cross-linking agent was confirmed by FTIR analysis. The pore sizes of acrylate foam were between 1 μm and 8 μm according to SEM analysis. This material was very suitable to absorb aqueous fluids.     

Application of the multireference equation of motion coupled cluster method,including spin–orbit coupling,to the atomic spectra of Cr,Mn, Fe and Co

The recently introduced multireference equation of motion (MR-EOM) approach is combined with a simple treatment of spin–orbit coupling, as implemented in the ORCA program. The resulting multireference equation of motion spin–orbit coupling (MR-EOM-SOC) approach is applied to the first-row transition metal atoms Cr, Mn, Fe and Co, for which experimental data are readily available. Using the MR-EOM-SOC approach, the splittings in each L-S multiplet can be accurately assessed (root mean square (RMS) errors of about 70 cm^?1). The RMS errors for J-specific excitation energies range from 414 to 783 cm^?1 and are comparable to previously reported J-averaged MR-EOM results using the ACESII program. The MR-EOM approach is highly efficient. A typical MR-EOM calculation of a full spin–orbit spectrum takes about 2 CPU hours on a single processor of a 12-core node, consisting of Intel XEON 2.93 GHz CPUs with 12.3 MB of shared cache memory.     

Asymmetric Cyclic Phosphorothonamides Containing Substituted Pyridine

In order to find high-acitivity and low-toxicity pesticidal lead compounds, a type of novel, asymmetric cyclic phosphorothonamides containing substituted pyridine were synthesized via the condensation reactions of 2-chloro-4-substitutedphenyl-5,5-dimethyl-1,3,2-dioxaphosphinane 2-sulfide with 3-aminomethylpyridine. The cis and trans isomers of the products were isolated by column chromatography on silica gel. The structures of the products were characterized by ¹ H NMR, ³¹ P NMR, MS, and elemental analyses. The configuration of 3a was determined by X-ray diffraction analysis. The results of the preliminary bioassay showed that the new compounds possess potential fungicidal activities.     

Synthesis and Stereochemistry of α-Aryl-β-Nitroalkylphosphinate

Abstract

Twenty-three new α -aryl-β -nitroalkylphosphinates 3a - g were synthesized in high yields under very mild conditions. Compounds 3 consist of two pairs of diastereomeric isomers (A) and (B)     

Composition heterogeneity of tetrafluoroethylene-hexafluoropropylene random copolymers characterized by successive self-nucleation and annealing

In the present work, successive self-nucleation and annealing (SSA) was applied to a series of tetrafluoroethylene-hexafluoropropylene random copolymers (FEPs). Multiple melting peaks were observed for all FEP samples after SSA thermal treatment. The lamellar crystal thicknesses were calculated from the melting temperatures, and the mass percentages of the crystals of specific thickness were obtained from the areas of the melting peaks. As a result, distributions of the lamellar thickness, which can be correlated to the composition distribution, were determined. It was found that the composition distribution of the FEP samples tended to become more heterogeneous as the content of hexafluoropropylene (HFP) comonomer increases. Samples with the same HFP content might also have different composition distributions.