Blend Identification

Assay/uniformity of blends Identification of clinical dosage forms... 

Fig. 3 Stress-strain curves of the transitional Copolymer D/PPO blends. Identification is the same as in Fig. 2 except that Curve 1 represents unblended Copolymer D (0% PPO).

Fig. 11 Tensile stress at break (or yield) versus volume fraction PPO for the incompatible PpClS/PPO blends. Identification is the same as in Fig. 9. Curve 1, the Schrager model for poor adhesion (Eq. 6, r = 2.66) curve 2, data for untreated glass bead/PPO composites (Eef. 24) curve 3, silane treated glass bead/PPO composites (Ref. 24).

Py-GC) pol5mier mixtures and blends identification by mass spectra ... 

Smith [841] has discussed applications of pyrolysis techniques for polymeric systems with emphasis on the qualitative identification of components in a copolymer or polymer blend, identification of low-level polymer contaminants, characterisation of copolymer sequencing, differentiation between copolymers and physical blends of homopolymers, determination of monomer ratios in copolymers, and the study of polymer kinetics and degradation mechanisms. Pyrolysis destroys the stereostructure of the polymers. Gaseous components generated from pyrolysis of a wide variety of polymers have been analysed both off-line and on-line by IR spectroscopy to determine (quantitatively) the major components of the parent resin, e.g. rubbers... 

LabRam Application Note R-29, Polymer Blends - Identification and Mapping of Phases, Jobin Yvon, Edison, NJ (1998). 

Visual and Manual Tests. Synthetic fibers are generally mixed with other fibers to achieve a balance of properties. Acryhc staple may be blended with wool, cotton, polyester, rayon, and other synthetic fibers. Therefore, as a preliminary step, the yam or fabric must be separated into its constituent fibers. This immediately estabUshes whether the fiber is a continuous filament or staple product. Staple length, brightness, and breaking strength wet and dry are all usehil tests that can be done in a cursory examination. A more critical identification can be made by a set of simple manual procedures based on burning, staining, solubiUty, density deterrnination, and microscopical examination. 

The woolen processor is relatively close to the consumer market. The essence of its success is the identification of lucrative markets in apparel or home finishings and the appropriate choice of the most cost-competitive blend fiber input. Technical experience, skillful design, and effective marketing are mandatory. 

It is suitable, not only for rose odours, but also for blending with almost any flower oil. Phenyl-ethyl alcohol forms a solid compound with chloride of calcium, which is very useful for its purification. On oxidation it is converted into a mixture of phenyl-acetaldehyde and phenyl-acetic acid. The last-named body forms an ethyl ester melting at 28°, which serves for its identification. 

Products manufactured using concepts in UL Standard 746D provide quick verification of material identification, along with the assurance that acceptable blending or simple compounding operations are used that would not increase the risk of fire, electrical shock, or personal injury. 

Comparative x-ray absorption measurements were used in the identification of various new compounds that could contain at most the following elements carbon, hydrogen, fluorine, and chlorine. The presumed composition of each compound, known in advance, was duplicated by properly blending carbon tetrachloride, benzotrifluoride, heptane, and benzene the latter also was used as solvent for the unknown. Under conditions intended to be identical, the amount of unknown... 

Principle. By means of potentiometric titration (in nonaqueous media) of a blend of sulfonic and sulfuric acids, it is possible to split the neutralization points corresponding to the first proton of sulfuric acid plus that of sulfonic acid, and to the second proton of sulfuric acid. The first derivate of the titration curve allows identification of the second points the corresponding difference in the volume of titrating agent is used as a starting point in the calculation method (Fig. 4). 

For betaxanthins, partial synthesis is quite common and presents a viable tool for identification by co-injection experiments. - Starting from a red beet extract or semi-purified betanin-isobetanin blend, alkaline hydrolysis by addition of 32% ammonia is initiated. Spectrophotometric monitoring at 424 nm allows the release of betalamic acid to be followed. Betaxanthins are obtained through the addition of the respective amino acid or amine in at least 20-fold molar excess followed by careful evaporation. Since the starting material most often consists of a racemic betacyanin mixture, the resulting betaxanthin will also consist of two stereoisomers that may not easily be separated by HPLC. ... 

Most dyes, including sulfonated azo dyes, are nonvolatile or thermally unstable, and therefore are not amenable to GC or gas-phase ionisation processes. Therefore, GC-MS techniques cannot be used. GC-MS and TGA were applied for the identification of acrylated polyurethanes in coatings on optical fibres [295]. Although GC-MS is not suited for the analysis of polymers, the technique can be used for the study of the products of pyrolysis in air, e.g. related to smoke behaviour of CPVC/ABS and PVC/ABS blends [263],... 

Dynamic IR spectroscopy coupled with 2D correlation analysis can provide insights into submolecular interactions in blends and compounds [1017], 2D IR spectroscopy allows identification of specific interactions between components in polymer mixtures. While blends and copolymers have been studied [1026], no reports on compounds have yet appeared. Applications of 2D IR spectroscopy to polymeric materials have been reviewed [1017,1026]. 

Identification of Peaks from Crystallographic Data. Crystallography is not an issue of X-ray scattering. However, even in materials science crystallographic data are frequently consulted11. Based on such data the crystallizing species (component of a blend, block of a block copolymer, one of the crystal modifications possible) can... 

Identification of compounds in volatiles collected from hunting M. cornigera revealed three common components of moth sex pheromone blends (Z)-9-tetradecenal, (Z)-9-tetradecenyl acetate, and (Z)-ll-hexade-cenal [while there was insufficient material for mass spectrometry, gas chromatographic retention time evidence suggests that (Z)-ll-hexadece-... 

The most recent converts are in the health care industry. Pharmaceutical and biological applications have become myriad since the early 1980s. The first widespread application was for the identification/ qualification of incoming raw materials. Since then, applications have appeared for moisture (bound and free), blend uniformity of powders, tablet and capsule assays, counterfeiting, polymorphism, degree of crystallinity, hardness (of tablets), dissolution prediction, isomerism, as... 

As a consequence, for unequivocal identification of the constituents of complex mixtures found in surfactant blends and also in the analyses of surfactants and their metabolites in environmental samples, MS and tandem mass spectrometry (MS-MS) have proved to be more advantageous and are discussed thoroughly in Chapter 2. To optimise the output of reliable results and to save manpower and time certain procedures in sample preconcentration, clean-up and separation prior to MS examinations are inevitable. These are discussed in the present book in more detail in Chapter 3. 

These results obtained from the analyses of industrial blends proved that the identification of the constituents of the different surfactant blends in the FIA-MS and MS-MS mode can be performed successfully in a time-saving manner only using the product ion scan carried out in mixture analysis mode. The applicability of positive ionisation either using FIA-MS for screening and MS-MS for the identification of these surfactants was evaluated after the blends examined before were mixed resulting in a complex surfactant mixture (cf. Fig. 2.5.7(a)). Identification of selected mixture constituents known to belong to the different blends used for mixture composition was performed by applying the whole spectrum of analytical techniques provided by MS-MS such as product ion, parent ion and/or neutral loss scans. 

First a screening in the APCI—FIA—MS(+) and APCI—FIA—MS(—) mode was carried out. From the positively generated overview spectrum as presented in Fig. 2.5.7(a) for identification, characteristic parent ions already known from the FIA—MS spectra of the pure blends and examined by MS—MS now were selected for MS—MS examination of the mixture. From the composed surfactant mixture, the ions at m/z 380, 556 and 670 were submitted to CID in positive APCI—FIA—MS—MS mode. Product ion spectra of these ions are presented in Fig. 2.5.7(b)—(d). 

Applying product and parent ion scans in the FIA-MS-MS(+) mode, the unequivocal identification of the AE blend constituents is not possible. The reason for this failure is the simultaneous presence of C12 and Ci4 AE and AES compounds in the mixture that, under positive APCI ionisation conditions, were ionised with the same patterns of [CnH2n+iO(CH2-CH2-0) + NH4]+ ions (A m/z 44) and the same ion masses according to n, the alkyl chain lengths, and x, the polyether chain lengths. The destructive ionisation process of AES in APCI(+) mode therefore imagines a differentiation of the A m/z 44 compounds but results are not reliable. 

While the surfactant mixture composed by mixing the different blends could be cleared up by FIA-MS and MS-MS to a great extent, these methods failed in the identification of most constituents contained in a commercially available household detergent formulation. The limitations of mixture analysis became obvious with the application of the API methods such as ESI and APCI in FIA-MS-MS mode and are described here by means of examples. 

By summing up the results of qualitative analysis of surfactant blends and formulations achieved by FIA-MS and MS-MS in comparison with LC-MS and MS-MS applied for identification, considerable differences could be observed and should be taken into consideration prior to analysis ... 

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