Blast furnace slags as functional fillers on rheological,thermal, and mechanical behavior of thermoplastics

Blast furnace slags (BFS) is a secondary byproduct of iron industry, which has a combination of acidic and basic oxides and show a complex, multiphase structure. If appropriately tailored, BFS could be an effective functional filler, improving the property profile of thermoplastics such as polypropylene (PP) and polystyrene (PS). As a raw material, the proposed filler may introduce both economic and ecological advantages, as it is considered an inexpensive secondary product rather than a natural resource. The current study aims at investigating the effect of incorporating BFS as a micro‐sized filler on the rheological, thermal, and mechanical behavior of PP and PS. BFS types in this study are air‐cooled, crystalline, and amorphous, grounded types. Both types are ground into 71, 40, and 20 μm batches and introduced in 10, 20, and 30 weight fractions via melt kneading. Mixtures are then formed into 4‐mm and 2‐mm thick plates via compression molding. Slight increase in rheological factors is observed with increasing filler loading. BFS hinders the crystallization of PP, resulting in slight increase of crystallization temperatures (T_c) and lowering of crystallization enthalpy (ΔH_c). No significant effect of filler on transition temperatures (T_g) is reported. Mechanically, BFS increases the tensile modulus of PP, but decreases its strength. For PS formulations, a modest toughening effect is observed by slag filler. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43021.     

Didesoxy-Ribonucleoside durch Schmelzkondensation

Dideoxy Ribonucleosides by Fusion Method The dideoxy nucleosides 2 , 4 and 6 are synthesized from the 1-O-acetyl-2,3-dideoxyribose derivatives 1 , 3 and 5 by fusion with chlorinated purines and other nitrogen heterocycles at 110–120°C without added catalyst. The ¹H-NMR and ¹³C-NMR spectra of the compounds are given.     

Kernel‐based gluten contamination of gluten‐free oatmeal complicates gluten assessment as it causes binary‐like test outcomes

Gluten‐free (GF) foods, whose claim compliance is controlled at the ‘serving level’, hold better chances of protecting gluten‐intolerant consumers. This is particularly true for GF oatmeal, as oats are easily contaminated with gluten‐rich kernels of wheat, rye and barley, which remain intact to the spoon as pill‐like flakes. A single contaminant kernel in otherwise pure oats results in GF labelling noncompliance, thereby posing a risk to patients with coeliac disease. Our in‐market survey of 965 GF oatmeal servings uncovered that one in fifty‐seven servings exceeded the GF labelling maximum of 20 mg kg^?1 (i.e. 20 ppm). The noncompliance pattern was ‘binary‐like’, with kernel‐based contamination the suspected pass/fail driver. We have highlighted probabilities of misassessment for various sample sizes in light of oat's natural propensity for kernel‐based contamination and proposed use of attribute‐based sampling for compliance assessment, thereby providing a way to assess/manage/control ‘rates of servings containing a contaminant kernel’ within acceptable limits with high confidence.     

Characterization of microorganisms in Argentinean honeys from different sources

Seventy polyfloral honeys including commercial samples obtained from supermarkets, harvested from apiaries and purchased in bulk were initially examined for total antibacterial activity. From each sample, numbers of aerobic mesophilic bacteria, total coliforms, moulds and yeasts were determined and the presence of Salmonella spp., Shigella spp., Clostridium sulfite-reducers, Paenibacillus larvae and Bacillus spp. was investigated. Moisture content, pH and total acidity were also determined for all samples. Any honey diluted to concentrations from 75% to 1% (w/v) of full-strength honey showed total antibacterial activity. The numbers of aerobic mesophilic bacteria, moulds and yeasts were less than 10(3) cfu/g for all 70 samples. Faecal coliforms, Escherichia coli, Salmonella spp., Shigella spp. and Clostridium sulfite-reducers were not detected but P. larvae subspp. larvae, Bacillus cereus, Bacillus pumilus and Bacillus laterosporus were found among samples. For commercial, apiary and bulk honey the mean values for moisture content, pH and acidity, respectively, were 17.50%, 17.40% and 17.50%; 4.60, 4.10 and 4.20; and 18.30, 20.60 and 21 meq NaOH/kg. P. larvae was recovered from 35% of apiaries including hives in which the bees did not display symptoms of American foulbrood disease.     

Azacrown Ethers with Naphthyl Branches. Fluorescence Properties,Protonation and Metal Coordination

Starting from 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane, we have prepared two compounds by replacing the amine hydrogens with naphthyl or 3,5-bis(2′-oxymethylnaphthyl)benzyl units. The absorption and emission spectra of compounds 2 (N,N′-bis(2-naphthylmethyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane) and 3 (N,N′-bis[3,5-bis(2′-oxymethylnaphthyl)benzyl]-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane) have been studied in CH₃CN:CH₂Cl₂ 1:1 (v/v) solution. For comparison purposes, the spectroscopic properties of N-methyl(2-methylnaphthalene)ethylamine (1) have also been investigated. For each compound, the absorption spectra are qualitatively very similar to that of naphthalene, with molar absorption coefficients as expected for the presence of one (1), two (2), and four (3) naphthyl chromophoric groups. The fluorescence spectra, however, are quite different from that of naphthalene. The naphthalene-type fluorescence (λ_max = 337 nm) is strongly quenched, particularly for compounds 1 and 2 which also exhibit a broad emission band in the visible region (λ_max ≈ 480 nm) assigned to a low lying charge-transfer excited state. In the case of compound 3, a quenched naphthalene-type band is accompanied by weak exciplex and excimer emissions. Upon titration with CF₃SO₃H, the charge transfer bands of 1 and 2 and the exciplex emission of 3 disappear and the naphthalene-type bands regain intensity. Titration plots show that in compounds 2 and 3 the protonation of the two nitrogens occurs stoichiometrically in two distinct steps. Titration with Zn²⁺ gives rise to 2.Zn²⁺ and 3.Zn²⁺ complexes. This article is dedicated to Professor Dedier Astruc.     

Enzymes in organic synthesis. 2. Synthesis of enantiomerically pure prostaglandin intermediates by Enzymatic Hydrolysis of (1SR, 5RS, 6RS, 7RS)-7-acetoxy-6-acetoxymethyl-2-oxabicyclo[3.3.0]octan-3-one

Subtilisin DY as well as alkaline protease from Bacillus licheniformis 41 p catalyze the hydrolysis of (1SR, 5RS, 6RS, 7RS)-7-acetoxy-6-acetoxymethyl-2-oxabicyclo[3.3.0]octan-3-one ( rac-1 ) with practically useful enantio- and regioselectivity. Under the hitherto found optimal conditions (1S, 5R, 6R, 7R)-7-hydroxy-6-hydroxymethyl-2-oxabicyclo[3.3.0]octan-3-one ( 4 ), an important intermediate in prostaglandin syntheses, could be prepared in a yield of 16% with an enantiomeric excess of 99%. The enantiomer ( ent-4 ) was obtained with the same enantiomeric excess in 20% yield. The chemical yields are related to the racemic starting material rac-1 .