The dynamic properties of solid tetrakis(trimethylsily))methane \(\left(\mathrm{C}\left(\mathrm{Si}\left(\mathrm{CH}_{3}\right)_{3}\right)_{4} ;\right.\) TTMSM) have been determined using high-resolution solid state \({ }^{13} \mathrm{C}\) and \({ }^{29} \mathrm{Si}\) NMR spectroscopy. TTMSM is know
Characterization of flame-retarded polymer combustion chars by solid-state 13C and 29Si NMR and EPR
โ Scribed by Jeffrey W. Gilman; Serge Lomakin; Takashi Kashiwagi; David L. VanderHart; Vitaly Nagy
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 141 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0308-0501
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โฆ Synopsis
We report here on the results of our continuing effort to study the flame-retardant mechanism of silica gel and potassium carbonate. These additives reduce the flammability of a wide variety of common polymers such as polypropylene, nylon, polymethylmethacrylate, poly(vinyl alcohol), and cellulose. In an effort to determine how these additives reduce polymer flammability, we have used electron paramagnetic resonance spectroscopy and solid-state 13 C and 29 Si nuclear magnetic resonance spectroscopy to characterize the combustion chars or residues. These data indicate that, in the case of poly(vinyl alcohol), the additives do not change the type of char formed, but they do change the rate of char formation relative to the rate of fuel generation. We also found that, using only CP/MAS 13 C NMR, there can be significant intensity distortions which complicate interpretation, if the char is hydrogen depleted and contains paramagnetic centres.
๐ SIMILAR VOLUMES
The solid-state Nuclear Magnetic Resonance (NMR) was used to characterize surfaces of silica gels chemically modified by alkenyltrialkoxysilanes and trialkoxysilyl terminated 1,4-polyisoprenes. The formation of covalent bonds created between alkoxy functional groups from alkenyltrialkoxysilane or tr
29 Si magic angle spinning (MAS) NMR, 27 Al MAS NMR and 27 Al triple-quantum MAS NMR were used to study the dealumination of offretite occurring during hydrothermal treatment. Deformed tetrahedral ( Si-O-) 3 Al-OH species and two octahedral extra-framework species are formed during the course of th