Fourier transform infrared spectroscopy and chemometrics as a tool for the rapid detection of other vegetable fats mixed in cocoa butter

The Fourier transform infrared (FTIR) technique in combination with multivariate data evaluation was used to analyze a wide variety of cocoa butters (CB), cocoa butter equivalents (CBE), and mixtures thereof. The sample set consisted of 14 CB (10 pure from various geographical origins and 4 commercial mixtures), 18 CBE (12 mixtures and 6 pure CBE from kokum, illipé, and palm midfraction), and 154 mixtures of CB with CBE at various concentrations (ranging from 5 to 20%). A total of 192 samples were analyzed in triplicate. All CB and CBE were shown to have very characteristic FTIR spectra that gave highly reproducible fingerprints. The main vibrational modes were also elucidated. FTIR can easily be employed to distinguish between pure CB and pure CBE. With prior knowledge of which cocoa butter is present in mixtures, FTIR can be applied to distinguish between CB mixed with CBE at the 10 and 20% levels (corresponding to about 2 and 5% of CBE in chocolate). However, the study revealed that a single “global” statistical model (multilayer perceptron, radial basis functions, or partial least square regression) was not able to predict the precise level of addition. The FTIR approach detailed here shows great potential as a rapid screening method for distinguishing between pure vegetable fats and, we believe, could be extended to investigate mixtures of CB and CBE by the establishment of a database.     

Physical Properties of Chocolate with Addition of Cocoa Butter Equivalent of Moderate Hardness

In this study, the fat phase of chocolate samples which contained cocoa butter from Ghana and cocoa butter equivalent (CBE) of moderate hardness was analyzed. Physical properties and shelf life of chocolate depend on the fat phase behavior as well as the amount and composition of added CBE. The laboratory-made chocolate samples were tempered at three different pre-crystallization temperatures (25, 27 and 29 °C), with three different concentrations of CBE, amounting to 3, 5 and 7 %, calculated on chocolate. The color and other physical attributes of chocolate samples were investigated by the following analytical methods: thermoreographic measurement, solid fat content (SFC) of chocolate, Blooming test (thermo-cycle test 32/20 °C) and color measurement. It was found that using CBE of moderate hardness did not change the melting properties of chocolate in relation to the investigated cocoa butter from Ghana (of moderate hardness). It was found that all three applied temperatures of pre-crystallization are optimum for the chocolate mass with the addition of the investigated CBE under the given measurement conditions. At all these temperatures, the chocolate had excellent fat bloom resistance.     

Preparation of sulfonated polypropylene and its dyeability: Thiol as a functionalization template of polypropylene

A two-step process has been invented to prepare sulfonated polypropylene from chlorinated polypropylene via thiolation and successive oxidation to enhance the dyeability of polypropylene. With a short thiolation reaction time of 3 h in an N-methyl-2-pyrrolidone solution, 1.7–20.5% sulfur can be incorporated into a polypropylene bulk effectively. Chlorine–thiol substitution and hydrosulfide conversion have been examined with elemental analysis, and their behaviors as a function of the SH/Cl ratio can be explained with an equilibrium model of hydrosulfide and accessible chlorine in a given timescale. Oxidation of thiol has been performed successfully with hydrogen peroxide. The evolution of oxidation intermediates such as sulfoxide, sulfone, sulfinic acid, and sulfonic acid can be identified by Raman and Fourier transform infrared analyses. Sulfonated polypropylene can be stained by a basic dye very effectively, and its dye uptake reaches 190 mmol of dye/kg of polymer for 3.6 mmol of sulfur/g of polymer. This dye uptake is 20 times more effective than that of chlorinated polypropylene on a molar basis. Thus, it is clear that a modification can be performed effectively to enhance the dyeability of polypropylene. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Rheology as a tool in concrete science: The use of rheographs and workability boxes

Rheology can supply valuable and practical information regarding the properties of fresh concrete, how to reach an optimization of the product and how to attain it by the use of rheograph. Otherwise, the optimization is largely based on feeling. The rheograph reveals in a systematical way the effects of diverse changes on the rheological behavior of the cement based suspension and thus is a convenient and essential tool to compare different concrete types and examine the behavior relative to changed quantities of constituents. Effects of many admixtures as well as the basic constituents of fresh concrete have been revealed in rheographs. In principle the effect of two or more constituents can be added in a rheograph to estimate the combined effect, which constitutes a so-called vectorized-rheograph approach.Different applications and types of concrete like slipform, underwater, and high strength, are described by workability boxes. New rheograph with boxes for various types of self compacting concrete is proposed.     

Preparation of a poly(L-lactide-co-caprolactone) copolymer using a novel tin(II) alkoxide initiator and its fiber processing for potential use as an absorbable monofilament surgical suture

A poly(L-lactide-co-caprolactone) copolymer, P(LL-co-CL), of composition 75:25 mol% was synthesized via the bulk ring-opening copolymerization of L-lactide and ε-caprolactone using a novel bis[tin(II) monooctoate] diethylene glycol coordination-insertion initiator, OctSn-OCH₂CH₂OCH₂CH₂O-SnOct. The P(LL-co-CL) copolymer obtained was characterized by a combination of analytical techniques, namely nuclear magnetic resonance spectroscopy, gel permeation chromatography, dilute-solution viscometry, differential scanning calorimetry, and thermogravimetric analysis. For processing into a monofilament fiber, the copolymer was melt spun with minimal draw to give a largely amorphous and unoriented as-spun fiber. The fiber's oriented semicrystalline morphology, necessary to give the required balance of mechanical properties, was then developed via a sequence of controlled offline hot-drawing and annealing steps. Depending on the final draw ratio, the fibers obtained had tensile strengths in the region of 200–400 MPa.     

New developments in polymer science and technology using combination of ionic liquids and microwave irradiation

The purpose of this review is to provide appropriate details concerning the application of ionic liquids (IL)s associated with microwave-assisted polymer chemistry. From the viewpoint of microwave chemistry, one of the key significant advantages of ILs is their high polarity, which is variable, depending on the cation and anion and therefore can effectively be tuned to a particular application. Hence, these liquids offer a great potential for the innovative application of microwaves for organic synthesis as well as for polymer science. ILs efficiently absorb microwave energy through an ionic conduction mechanism, and thus are employed as solvents and co-solvents, leading to a very high heating rate and a significantly shortened reaction time. Since an IL-based and microwave-accelerated procedure is efficient and environmentally benign, we believe that this method may have some potential applications in the synthesis of a wide variety of vinyl and non-vinyl polymers. This review describes application of combination of ILs with microwave irradiation as a modern tool for the addition and step-growth polymerization as well as modification of polymers and it was compared with ILs alone and conventional polymerization method.