Typical polymer pyrograms

TYPICAL POLYMER PYROGRAMS 6.7.1 Filament and Furnace Pyrolysis... 

DATA COMPILATION OF PYROGRAMS, THERMOGRAMS AND MS DATA OF MAJOR PYROLYZATES FOR 163 TYPICAL POLYMER SAMPLES... 

Silicone paints are formed by controlled hydrolysis and condensation of alkyl alkox-ysilanes, and may be encountered either alone or in formulations with other synthetic resins. The typical structural unit in the polymer chain is dimethyl siloxane, and pyrolysis of such resins takes place with random chain scission and the extended formation of stable cyclic fragments. In Figure 12.14 the pyrogram of a silicone resin is shown, with cyclic siloxane oligomers eluting at the shorter retention times, followed by the linear siloxane fragments. 

Figure 4.6 shows the typical portions of the expanded pyrograms around Cn fragments for a LDPE and those of five model copolymers for methyl, ethyl, butyl, amyl, and hexyl branches. Once relative peak intensities characteristic of the SCBs are determined using well-defined model polymers with known amounts of possible SCBs, the relative abundance of the SCBs in the LDPE can easily be estimated by the peak simulation of the observed isoalkane peaks in the pyrogram of the LDPE. ... 

The THM reaction linked to GC, GC/mass spectrometry (MS), and MS has been successfully applied to the chemical characterization of a number of synthetic and natural products, including resins, lipids, waxes, wood products, soil sediments, and microorganisms. This technique is also very effective for the detailed characterization of the synthetic polymeric materials, especially the condensation polymers, such as polyesters and polycarbonates, because many simplified pyrograms are usually obtained that consist of peaks of methyl derivatives from the constituents of the polymer samples almost quantitatively. In this chapter, the instrumental and methodological aspects of Py-GC in the presence of the organic alkali are briefly described, and then some typical applications to the precise compositional analyses and microstructural elucidation inclusive of the intractable cross-linking structures for various condensation type polymeric materials are discussed. 

A pyrolysis temperature of 500 "C was chosen to obtain a higher yield of trimer for styrene and n-butyl acrylate (BA). Figure 5.14 shows the typical pyrogram of a 50%/50% by weight STY/BA homogeneous emulsion polymer. Figure 5.15 is an expansion of the trimer area in Figure 5.14. 

Figure 7.13 Typical pyrogram of a 50%/50% by weight STY/w-BA homogeneous emulsion polymer. (Reprinted with permission from F.C-Y. Wang and P.B. Smith, Analytical Chemistry, 1996, 68, 17, 3033. 1996, ACS, USA. [144])...

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