Synthesis of Two Natural Furan‐Cyclized Diarylheptanoids via 2‐Furaldehyde

Two natural diarylheptanoids, 2‐benzyl‐5‐(2‐phenylethyl)furan ( 1 ) and 2‐methoxy‐4‐{[5‐(2‐phenylethyl)furan‐2‐yl]methyl}phenol ( 2 ), were synthesized starting from 2‐furaldehyde. A Wittig reaction of 2‐furaldehyde with benzyltriphenylphosphonium bromide followed by reduction of the alkene C?C bond with Mg gave 2‐(2‐phenylethyl)furan ( 5 ). Lithiation of 5 with BuLi at ?78° followed by alkylation with benzyl bromide gave natural product 1 . In another approach, Friedel? Crafts acylation of compound 5 with benzoyl chloride followed by deoxygenation of the C?O group afforded 1 . The natural product 2 was also synthesized by acylation of 5 with 4‐acetoxy‐3‐methoxybenzoyl chloride ( 16 ) followed by deoxygenation and deacetylation.     

Modeling of particle–resin suspension impregnation in compression resin transfer molding of particle-filled,continuous fiber reinforced composites

A particle–resin suspension impregnation model is used for analyzing the mold filling process in compression resin transfer molding (CRTM) of particle-filled, continuous fiber composites. The model is based on Darcy flow coupled with particle filtration and is applicable to two-dimensional impregnation through isotropic/anisotropic fiber preforms. Comparisons with simple analytical solutions and experimental results from the literature were made to validate the numerical solution. Simulations showed that CRTM was advantageous over resin transfer molding (RTM) for smaller non-homogeneity in composite microstructure, when particle filtration was high. Limits on certain process parameters were observed beyond which molding pressures in CRTM became comparable with those in RTM. The preform anisotropy was effective in the particle distribution profile. The choice of inlet gate configuration in CRTM was found influential in the particle distribution homogeneity and molding pressures. The developed modeling tool can be extended to analyze any composite liquid molding process involving particle fillers.     

4-Vinylbenzenesulfonic acid adduct of epoxidized soybean oil: Synthesis, free radical and ADMET polymerizations

In this work new radically polymerizable triglyceride based monomers were synthesized by the reaction of epoxidized methyl oleate (EMO) and epoxidized soybean oil (ESO) with 4-vinyl benzene sulfonic acid (4VBSA). The products are 1-(4-vinylbenzene sulfonyl)oxy-2-alkonols of epoxidized soybean oil (SESO) and 1-(4-vinylbenzene sulfonyl)oxy-2-alkonols of epoxidized methyl oleate (SEMO). These adducts were characterized by ¹H NMR, ¹³C NMR, IR and CHNS elemental analysis. SESO was found to contain, on the average, 2.47 4VBSA units per triglyceride. SESO was free radically polymerized and co-polymerized with styrene and the mechanical and thermal properties of the resulting thermosets were determined by DMA, DSC and TGA. SEMO was used as a model compound to determine the efficiency of metathesis catalysts for these fatty acid derivatives. The second generation Hoveyda–Grubbs catalyst was found to give best yields. ADMET polymerization of SESO with this catalyst with and without solvent gave ∼80% yield of a thermoset polymer. Polymers obtained by free radical route swelled in water at room temperature, and hydrolyzed in water at 60 °C.     

Biosorbent for tungsten species removal from water: effects of co-occurring inorganic species

The effect of co-occurring inorganic species on the removal of tungsten from water was investigated using biosorbent (i.e., chitosan coated montmorillonite clay). Simulated natural water and well water from Fallon, NV were used for this study. The concentrations of tungsten (21-541 mg/L) and inorganic species ([H(2)CO(3)]=0-4.2 mg/L, [H(4)SiO(4)]=0-90 mg/L, and [SO(2-)(4)]=0-400 mg/L) in simulated feed water were varied. The concentration of tungsten in the well water was 26 microg/L. The pH level of simulated feed water and well water was adjusted to 4 since this pH was found to be the most effective pH for the tungsten removal using chitosan coated clay. Tungsten removal without the existence of co-occurring inorganic species decreases from 99.8 to 87.1% with an increase in initial tungsten concentration from 21 to 541 mg/L. It reduces further as the co-occurring inorganic species concentration increases. The percentage of the tungsten removal ranges between 68.2-93.8%, 66.7-94.2%, and 53.6-93.7% for simulated natural water containing varied amount of H(2)CO(3), H(4)SiO(4), and SO(2-)(4), respectively. The adsorption kinetic data could be best described by the pseudo second order expression. The adsorption equilibrium data was modeled with the Langmuir, Temkin, and Freundlich equations and was found to be represented well by the Langmuir equation. The essential characteristics of the Langmuir isotherm indicate that the adsorption of tungsten on chitosan coated clay is favorable regardless of the presence of interfering species. Compared to natural clay, chitosan coated clay has about 116 times larger adsorption capacity per gram of chitosan, which makes it a superior adsorbent. However, the maximum tungsten adsorption capacity decreases in the presence of co-occurring species since the co-occurring species suppress the adsorption. For the well water treated with biosorbent, the tungsten concentration in the product water was found to be lower than the detection limit (1 microg/L) of the inductively coupled plasma mass spectrometer (ICP-MS). The repeatable results obtained from the treatment of both simulated and well water suggest that using chitosan coated clay can be an efficient adsorbent for tungsten removal from contaminated sites.     

On the Quaternionic B 2-Slant Helices in the Euclidean Space E 4

In this paper we give a new definition of harmonic curvature functions in terms of B ₂ and we define a new kind of slant helix which we call quaternionic B ₂–slant helix in 4–dimensional Euclidean space E ⁴ by using the new harmonic curvature functions. Also we define a vector field D which we call Darboux quaternion of the real quaternionic B ₂–slant helix in 4–dimensional Euclidean space E ⁴ and we give a new characterization such as: "a: I ì \mathbb R ? E⁴{``\alpha : I \subset {\mathbb R} \rightarrow E^4} is a quaternionic B ₂–slant helix ${\Leftrightarrow H^\prime_2 -KH_{1} = 0"}${\Leftrightarrow H^\prime_2 -KH_{1} = 0"} where H ₂, H ₁ are harmonic curvature functions and K is the principal curvature function of the curve α.     

New N,S-Substituted Nitrobutadienes from Mono(Arylthio)Substituted Nitrobutadienes

N,S-Substituted nitrobutadienes 3a–g were synthesized from the reaction of the thiosubstituted derivatives 1a–g with thiomorpholine 2. The N,S-substituted nitrobutadienes 5a–g were obtained from the reaction of the thiosubstituted butadienes 1a–g with N-diphenylmethyl piperazine 4. The structure of butadiene 3c was elucidated by single crystal X-ray diffraction.     

高分子担载席夫碱及其Cr（Ⅲ）配合物：合成、表征、抗菌和抗真菌性能评价

用胺甲基树脂与5-氟-2-羟基苯甲醛,5-氟-3-氯-2-羟基苯甲醛,5-氟-3-甲基-2-羟基苯甲醛反应合成了3种新颖的高分子担载席夫碱和它们Cr（Ⅲ）配合物,并用元素分析、磁化率、IR、1HNMR、UV-Vis、TG/DTA对其进行了表征。就一些革兰氏阳性菌（芽孢杆菌属腊状芽孢杆菌（Bacillus cereus sp）,单核细胞增生李斯特菌4b（Listeria monocytogenes 4b）,藤黄微球菌（Micrococcus luteus）,金黄色葡萄球菌（Staphylococcus aureus）表皮葡萄球菌（Staphylococcus epidermis））和革兰氏阴性菌（布鲁氏菌（Brucella abortus）,大肠杆菌（Escherichia coli）,恶臭假单胞菌SP（Pseudomonas putidasp.）,痢疾志贺氏菌10（Shigella dysenteria type 10）,伤寒杆菌H（Salmonella typhi H）和酵母菌（念珠菌）（yeast（Candida albicans））用井扩散法对高分子担载席夫碱和它们Cr（Ⅲ）配合物的生物学活性进行了筛选。     

Design,Synthesis and Characterization of 3,4-Dihydro-2H-pyran Containing Copolymer/Clay Nanocomposites

We introduce briefly surface modification of clay minerals, structure, properties and, characterization techniques of polymer-clay (PCN's) nanocomposites. Organically modified layered-silicates or nanoclays have become an attractive class of hybrid materials due to their prospective use in a great variety of applications from industry to health. For design, synthesis and characterization for potential biomedical nanocomposites, antitumor-active copolymer; poly(DHP-alt-MA) were used to prepare copolymer/clay nanocomposites. The functional copolymers, having a combination of rigid/flexible linkages and an ability of complex-formation with interlayered surface of organo-silicate, and their nanocomposites have been synthesized by interlamellar complex-radical copolymerization of intercalated monomer complexes of maleic anhydride (MA) and 3,4-Dihydro-2H-pyran (DHP) with three alkyl ammonium salts surface modified bentonite and monomer mixtures. Poly(DHP-alt-MA) pristine copolymer and poly(DHP-alt-MA)/organically modified bentonite nanocomposites were characterized by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), HR-Raman, X-ray diffraction (XRD) and TEM methods.