Fourier transform degradation products

The initial observation is that PMMA is essentially completely degraded to monomer by heating to 375°C in a sealed tube while heating a mixture of red phosphorus and PMMA under identical conditions yields a solid, non-deqraded, product as well as a lower yield of monomer. One may observe, by 3C NMR spectroscopy, that the methoxy resonance is greatly decreased in intensity and methyl, methoxy phosphonium ions are observed by 31P NMR. Additional carbonyl resonances are also seen in the carbon spectrum, this correlates with a new carbonyl vibration near 1800 cm 1 in the infrared spectrum and may be assigned to the formation of anhydride. The formation of anhydride was also confirmed by assignment of mass spectra obtained by laser desorption Fourier transform mass spectroscopy, LD-FT-MS. 

Uetake, N. 1987. Determination of degradation products in tributyl phosphate using 31P Fourier transform NMR spectroscopy. Analyst 112 445-448. 

Fourier transform infrared spectroscopy FT-IR. The measurement of individual degradation products with FT-IR is very simple, quick and precise. A reference sample spectrum of new oil is required to subtract electronically from the oil sample spectrum. The spectra of the fresh oil and the used oil sample are obtained individually in the same cell. The results - both spectra and the "differential" spectrum are stored in the computer in absorbance format, a form that varies linearly with concentration. 

The tables that follow contain information on the Chemical Warfare Agents Simulants (Table 2), degradation products of actual chemical agents (Table 3) and on the Toxic Industrial Compounds (Table 4) studied. Raman Spectroscopy and Fourier Transform Infrared Spectroscopy were used for the vibrational analysis. Spectra were compared to... 

Fourier transform infrared (FT-IR) spectroscopy can be used to characterize drug substances, polymer blends, polymer complexes, dynamics, surfaces, and interfaces, as well as chromatographic effluents and degradation products. It provides information about the complexation and interactions between the various constituents in the PECs. It is capable of qualitative identification of the structure of unknown materials as well as the quantitative measurement of the components in a complex mixture. FT-IR spectra of physical mixture and PEC can be determined by FT-IR spectrophotometer using KBr disc method in the range of 4000 to 250 cm h Since the stability and drug substance is very important in several applications, determination of their physicochemical stability is crucial. The FTIR spectra of polyacrylic acid, PVP, metformin hydrochloride, and PEC microparticles of metformin were shown in Figure 56.8. The FTIR spectra of polyacrylic acid and PVP have shown... 

On the other hand, the pyrolysis products of a Nomex-type aramid and its chloro-derivative at 450 and 550°C were identified by GC-Fourier-transform infrared (FTIR) and GC/MS. The end groups of the volatile degradation products reported were anune, nitrile, carboxylie acid, and phenyl for both one-ring and two-ring compounds. The formation of the two-ring compounds occurred preferably at 450°C, whereas pyrolysis at 550°C yielded predominantly the one-ring compounds. Moreover, Nomex and Kevlar were pyrolyzed at several temperatures between 300 and 700°C. At lower temperatures, water was almost exclusively formed as a volatile... 

Hummel and co-workers [105], using pyrolysis with a combination of mass spectrometry and Fourier transform infrared (FT-IR) spectroscopy identified many degradation products. CO2 and CO showed release maxima at 520 ° and 550 °C, respectively, whereas the following materials exhibited evolution maxima as noted ... 

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