Thermogravimetric analysis nanocomposites

The impact of the nanocomposite technology on polymers is huge, reflected in enhanced properties of the resulting PNs, such as enhanced mechanical, barrier, solvent-resistant, and ablation properties.12 The effect of nanocomposite technology on the thermal and fire performance of the polymers is primarily observed in two important parameters of the polymers (1) the onset temperature (7( ,nsct) in the thermogravimetric analysis (TGA) curve—representative of the thermal stability of the polymer, and (2) the peak heat release rate (peak HRR) in cone calorimetric analysis (CCA)—a reflection of the combustion behavior (the flammability) of the polymer. The Tonset will be increased and the peak HRR will be reduced for a variety of polymers when nanoscale dispersion of the nanoadditive is achieved in the polymer matrix. 

D. Wang, K. Echols, and C.A. Wilkie, Cone calorimetric and thermogravimetric analysis evaluation of halogen-containing polymer nanocomposites, Fire Mater., 2005, 29 283-294. 

Figure 4.14. Thermogravimetric analysis of EVA nanocomposites filled with 3 wt% Cloisite 30B and either 0,0.5 or 1.0 wt% purified MWNTs under air flow at 20 K/min (unfilled EVA matrix is shown for sake of comparison). Reprinted with permission from ref (66).

The mechanical properties of the C3, C6, and Cl2 nanocomposites were all significantly better than those of the neat phenolic resin, even if a very small amount of the silicate was used. Among the nanocomposites prepared, the organically modified MMT-resol systems showed better mechanical properties than those of the unmodified MMT-resol system. This improvement was attributed to the formation of an end-tethered structure due to the reaction of the carboxylic acid of the organic modifier with the methylol group of the phenolic resin. Thermogravimetric analysis reported by Byun and coworkers showed that the nanocomposite systems had similar thermal stability to that of the neat polymer. 

The mercaptide thermolysis may behave differently in the presence or absence of polymers [Conte et al., 2007]. However, in most cases, the inorganic phase generated by the thermal degradation of mercaptide molecules dissolved in polymer corresponds exactly to that resulting from the thermal degradation of pure mercaptide. Consequently, a preliminary study of neat mercaptide thermolysis by thermal analysis approaches [differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA)] is usually performed before nanocomposite preparation and characterization. 

The first notion of the polymeric nanocomposites was given in patent in 1950 [3]. Blumstain pointed in 1961 [4] that polymeric clay-based nanocomposites had increased thermal stability. It was demonstrated using the data of the thermogravimetric analysis that the polymethylmetaciylate intercalated into the Na+ - methylmetaciylate possessed the temperature of destmction 40-50°C higher than the initial sample. 

Thermogravimetric analysis of polyvinylidene-co-trifluoroethylene layered nanocomposites have indicated that their thermal stability is improved when the anionically modified layered silicate content was increased [30]. Differential scanning calorimetry showed that thermal transitions in the nanocomposites depended on the layered silicate content. 

The thermogravimetric analysis on TiO -polypropylene nanocomposite fibers show an increase in thermal degradation temperature for nanocomposite system compared to pristine polypropylene [67]. This improvement is attributed to the good adhesion between PP and TiO. Good interfacial adhesion between the particles and the polymer helps the nanoparticle to effectively restrict the motion of the polymer chain. It makes the fragmentation of the polymer chain harder at lower temperature and. shifts the degradation temperature to the higher side. 

Fitaroni, L.B., de Lima, J.A., Cmz, S.A., Waldman, W.R. Thermal stabihty of polypropylene-montmorillonite clay nanocomposites limitation of the thermogravimetric analysis. Polym. Degrad. Stab. Ill, 102-108 (2015)... 

Thermal properties Thermal properties are the properties of materials that change with temperature. They are studied by thermal analysis techniques, which include DSC, thermogravimetric analysis (TGA), differential thermal analysis (DTA), thermomechanical analysis (TMA), dynamic mechanical analysis (DMA)/dynamic mechanical thermal analysis (DMTA), dielectric thermal analysis, etc. As is well known, TGA/DTA and DSC are the two most widely used methods to determine the thermal properties of polymer nanocomposites. TGA can demonstrate the thermal stability, the onset of degradation, and the percentage of silica incorporated in the polymer matrix. DSC can be... 

Natural rubber-CaC03 nanocomposites Modified CaC03 addition into NR sulfur vulcanizing Calorimetry and thermogravimetric analysis for physical, thermooxidative aging and thermal degradation property assessment microstructure analysis [96]... 

Loos and co-workers [64] studied the effect of CNT on the mechanical and viscoelastic properties of epoxy matrices. Bisphenol A based epoxy resin nanocomposites were prepared with various small proportions of single-walled carbon nanotubes (SWCNT) and then investigated using acetone as a diluent to reduce the resin viscosity, and the products after removal of the solvent were characterised by FT-IR, Raman spectroscopy, thermogravimetric analysis (TGA), DSC, DMA, tensile, compression, flexural and impact testing, and SEM of the fracture surfaces. The effects of small amounts of SWCNT on mechanical and viscoelastic properties of the nanocomposites are discussed in terms of structural changes in the epoxy matrix. 

The decomposition temperature is a direct measure of the thermal stability of the nanocomposite materials. The derivative thermogravimetric analysis profile (DTA) (the inset of Figure 12.6a) shows two decomposition temperatures Tn and 7 2) for all the P3HT nanocomposites. The third decomposition temperature (7 ) assigned to MWNTs is visible only in the PM-5 and PM-10 samples. Tn originates... 

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