Quantitative analysis of polymers

Parker and Waddell investigated three methods [51]. These involved determining the %ACN as a function of  

Reprinted with label modifications from reference [49] with permission from Technomic Publishing Co., Inc., Copyright 1999 

Least squares linear regression analyses of the data over the range of 20%-50% ACN gave the following equations  

Traditional non-PA methods might involve measuring the 700 cm 1 styrene band in carbon disulfide solutions as carried out by Binder [52], transmission measurements on films 

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Applications Conventional GC is a workhorse in the qualitative and quantitative analysis of polymer additives in complex mixtures and has found numerous applications. Both GC and auxiliary techniques are particularly useful for characterisation of (semi)volatile constituents and additives ranging from gases to hydrocarbon waxes (fatty acids and their... 

Nowadays, MS is often no longer the analytical bottleneck, but rather what precedes it (sample preparation) and follows it (data handling, searching). Direct mass-spectrometric methods have to compete with the separation techniques such as GC, HPLC and SFC that are commonly used for quantitative analysis of polymer additives. Extract analysis has the general advantage that higher-molecular-weight (less-volatile) additives can be detected more readily than by direct analysis of the polymer compound. 

Principles and Characteristics Mass-spectral analysis methods may be either indirect or direct. Indirect mass-spectral analysis usually requires some pretreatment (normally extraction and separation) of the material, to separate the organic additives from the polymers and inorganic fillers. The mass spectrometer is then used as a detector. Direct mass-spectrometric methods have to compete with separation techniques such as GC, LC and SFC that are more commonly used for quantitative analysis of polymer additives. The principal advantage of direct mass-spectrometric examination of compounded polymers (or their extracts) is speed of analysis. However, quite often more information can be... 

Applications Applications of SEC-FTIR include quantitative analysis of copolymers [701] product deformulation of hot melt adhesives characterisation of polymer compositional heterogeneity analysis of complex mixtures of urethane oligomers and eventually also the identification and quantitative analysis of polymer additives... 

The challenge in FTIR quantitative analysis of polymers is the thickness of the sample. The use of peak ratios standardizes the absorbance signal and eliminates the thiekness variable. Attenuated total reflectanee (ATR) and microscope FTIR were the two methods ehosen to acquire the FTIR spectra. The filler eontent in the polymer was confirmed by ashing. 

The use of photoacoustic FTIR spectroscopy in quantitative analysis of polymers was investigated with reference to determination of vinyl acetate in EVA, acrylonitrile in NBR, ethylene in EPDM, styrene in SBR and vinyl-butadiene in SBR. The results obtained indicated that, despite the theoretical complexities of photoacoustic FTIR spectroscopy, simple quantitative relationships could be found for many of these polymer analyses. 24 refs. 

Figure 2 Positive ion ToF-SIMS spectrum from high-density polyethylene. (Reproduced with permission from Vanden Eynde X (2001) Quantitative analysis of polymer surfaces. In Vickerman JC and Briggs D (eds.) TOF-SIMS Surface Analysis by Mass Spectrometry, Ch.16. Manchester SurfaceSpectra/IM Publications SurfaceSpectra/IM Publications.)...

The improvement in the number of published works in this area during the last years is a clear sign of the importance of the methods based on chromatography for the qualitative and quantitative analysis of polymer and biopolymer additives. This trend is expected to continue in the coming years as a response to the more stringent international regulations about additives for plastic materials and the need for more specific properties of polymer materials. 

Ashraf-Khorassani, M. Nazem, N. Taylor, L.T. Feasibihty of supercritical fluid extraction with on-hne coupling reverse-phase hquid chromatography for quantitative analysis of polymer additives. J. Chromatogr. A, 2003, 995, 227-232. 

On the other hand, GC, because of the physical separation it effects, furnishes both a qualitative and a quantitative analysis of polymer-plasticiser mixtures with almost the same ease as the analysis of plasticisers alone, and this is discussed further in Chapter 5.1. It suffices to submit the sample, prepared as for the pyrolysis of plastics, to a controlled pyrolysis in order to disengage the vaporised plasticisers. The polymer is partially degraded, but its pyrolysis products were in all the cases studied by Guiochon and Hennicker [82] much lighter than the plasticisers and in no way prevented their separation and identification. Figure 4.18 shows the separation obtained of four plasticisers (a) dibutyl succinate, (b) tributyl phosphate, (c) dimethyl sebacate and (d) diethyl phthalate and the pyrolysis products of polyvinyl chloride. The latter are eluted during the first minute of operation. 

Adsorption Properties OWLS. Quantitative Analysis of Polymer Adsorption. Polymer adsorption properties were characterized by means of OWLS. The results of the OWLS experiments (the adsorption profile for PLL(6)-g[5]-dex(5.9) is shown in Eigure 2 as example) indicate that the PLL-g-dex copolymers spontaneously adsorb from aqueous solution (10 mM HEPES buffer, pH 7.4) onto metal oxide surfaces. Upon exposure of a waveguide surface to the polymer solution (after 70 min of exposure to HEPES buffer to achieve the baseline), the adsorption process occurred rapidly, such that more than 90% of the final mass of adsorbed polymer was reached within... 

Polymer specimens are particularly difficult to analyze in the AEM. Generally, there are small amounts of heavy elements in a polymer. These low levels are difficult to detect in a material that changes readily in the electron beam. These difficulties preclude routine quantitative analysis of polymers in either the SEM or AEM although microanalysis techniques can be applied. The major consideration for the polymer microscopist is that changes occur in the polymer during study. 

Today polymers scientists rely on many different methods of instrumental analysis to develop, test, and classify macromolecules. Infrared (IR) spectroscopy, one of the most important analytical tools in research as well as in manufacturing, is used to test the quality of incoming monomers, to control processes, to control quality control, and to confirm quality of intermediates and final products. IR is even used to troubleshoot processing problems and to analyze the competitor s products. IR spectroscopy has value in structure elucidation and quantitative analysis of polymers. Hausdorff [6] and Kagarese and Weinberger [7] were the first to publish collections of IR spectra of polymers. 

Sampling Procedures for Quantitative Analysis of Polymer/Additive Packages.600... 

SAMPLING PROCEDURES FOR QUANTITATIVE ANALYSIS OF POLYMER/ADDITIVE PACKAGES... 

Table 6.3. Characteristics of sampiing procedures for quantitative analysis of polymer/additive formulations ...

For the analytical spectroscopist working in a quality assurance laboratory or a research technical-support group, the need to provide cost-effective, robust, reproducible and simply operated quantitative methods of compositional and microstructure analysis can be a prime task and important challenge. Vibrational spectroscopy techniques have proved themselves among the most powerful for the routine quantitative analysis of polymers, with the wide variety of sampling procedures usually offering a method (at least semi-quantitative) for even the most intractable of materials. 

Chalmers, J.M. and Everall, N.J. (2002) Qualitative and quantitative analysis of polymers and rubbers by vibrational spectroscopy. In Handbook of Vibrational Spectroscopy, Vol. 4 (eds J.M. Chalmers and P.R. Griffiths), John Wiley Sons, Ltd, Chichester, pp. 2389-2418. 

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