Plasticizer analysis

Chemical Data Inc., Monthly Petrochemical and Plastics Analysis (fan. 1994). 

Torsional Braid Analyzer (TBA) B 10- -1 Plastics Analysis Instmments, Princeton, N.J. 

H. Lobo and J. Bonilla, Handbook of Plastics Analysis, M. Dekker, New York, NY (2003). 

A. Krause, A. Lange and M. Ezrin, Plastics Analysis Guide - Chemical and Instrumental Methods, Hanser Verlag, Munich (1983). 

D.O. Hummel, Atlas of Polymer and Plastics Analysis Analytical Methods, Spectroscopy, Characteristic Absorptions, Description of Compound Classes, Vol. 2, John Wiley Sons, Inc., New York, NY (1988). 

D. Hummel and F. Scholl, Atlas of Polymer and Plastics Analysis, Vol. 3, Additives and Processing Aids, Carl Hanser Verlag, Munich, Germany, 1981. 

Sandorf, 1980 Whitney, 1985 Whitney and Browning, 1985). According to the classical beam theory, the shear stress distribution along the thickness of the specimen is a parabolic function that is symmetrical about the neutral axis where it is at its maximum and decreases toward zero at the compressive and tensile faces. In reality, however, the stress field is dominated by the stress concentration near the loading nose, which completely destroys the parabolic shear distribution used to calculate the apparent ILSS, as illustrated in Fig 3.18. The stress concentration is even more pronounced with a smaller radius of the loading nose (Cui and Wisnom, 1992) and for non-linear materials displaying substantial plastic deformation, such as Kevlar fiber-epoxy matrix composites (Davidovitz et al., 1984 Fisher et al., 1986), which require an elasto-plastic analysis (Fisher and Marom, 1984) to interpret the experimental results properly. 

Fisher, S. and Marom, G. (1984). A complete elastic-plastic analysis of Aramid fiber composites. Composites Sci. Technol. 20, 91-98. 

Arnold, S.M., Arya, V.K. and Melis, M.E. (1990). Elastic/plastic analysis of advanced composite investigating the use of the compliant layer concept in reducing residual stresses resulting from processing, NASA TM-103204. 

D. O. Hummel, F Scholl, Atlas of Polymer and Plastics Analysis, 2nd edn, Hanser, Munich Wiley-VCH, Weinheim, New York (1986)... 

Plasticizer analysis Is Indispensable In establishing the purity of technical plasticizers and determining the chemical nature of plasticizers in finished and semi-finished articles. When plastics are used for food packaging and similar purposes, only certain nontoxic substances are acceptable as plasticizers, and this is why health authorities take an active interest In plasticizer analysis. Requirements such as these have promoted the development of analytical methods that are as simple and as time-saving as possible. This article deals with the present art of plasticizer analysis—Its methods and problems—based on the literature as well as on the results of the author s own Investigations. 

Plasticizer analysis requires use of both physical and chemical methods. Prior to analysis, mixtures must be separated. But plasticizers often have such low vapor pressures and high boiling points that standard separations—distillation and crystallization—are not adequate, and the analyst must use chromatographic separations. Currently, the most popular of these methods are ... 

Thin layer chromatography, as a kind of chromatography in open columns, has been upgraded to a simple technique in the last few years. But column chromatography obviously does not deserve this much attention in connection with plasticizer analysis. 

Compared to other plasticizer analysis methods, thin layer chromatography is simple and quick. If used alone, it does not always lead to positive identification of every unknown plasticizing agent, but it does indicate the presence ol a plasticizer or a mixture of plasticizing substances. 

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