Dynamic mechanical analysis nanocomposites

Giraldo et al. (38) reported polyamide 6 nanocomposites in which the crystallization temperature of the polymer was observed to increase with the addition of 2 wt% CNTs. The temperature was 185°C for the pure polyamide which subsequently increased to 190 °C. The authors suggested that the nanotubes might serve as the nucleation sites for the polymer crystals to grow which was also confirmed by the reduction of the chain mobility by dynamic mechanical analysis. The thermal stability of the composites was reported to enhance after the incorporation of nanotubes. 

The glass transition temperature (Tg) of cellulose reinforced composites is an important parameter which influences different properties of the resulting composite such as mechanical behavior, matrix chains dynamics and swelling behavior. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) are used to evaluate the Tg value of cellulose nanocomposites. In some cases, the addition of cellulose nanocrystals into polymer matrices does not seem to affect the... 

What information is obtained from the dynamic mechanical analysis of vegetable oil-based polymer nanocomposites ... 

Dynamic Mechanical Analysis of Clay-Polymer Nanocomposites... 

Figure 9.27 Dynamic mechanical analysis of epoxy nanocomposite (a) storage modulus and (b) tan S. Reprinted from [31] with permission from Elsevier.

Dynamic mechanical analysis is done by researchers to analyze the viscoelastic properties of polymer nanocomposites [3,73,80]. Omrani et al. studied the influence of nano-alumina on the viscoelastic properties of epoxy in... 

FIGURE 33.4. Comparison of flexural modulus between a pure epoxy and a 5% loaded epoxy/clay nanocomposite utilizing dynamic mechanical analysis. 

Pasquini et al. reported that cellulose whiskers with high aspect ratio extracted directly from cassava bagasse were used to prepare NR nanocomposite films by mixing with the NR latex emulsion. The mixtures were cast on Teflon plates and dried overnight to obtain composite films. These NR nanocomposite films were not vulcanized by standard process. They found that a significant increase of the storage tensile modulus was observed upon filler addition by dynamic mechanical analysis. 

Crosslinked NR nanocomposites were prepared with montmorillonite. Morphology was characterized using transmission electron microscopy (TEM), wide-angle X-ray scattering (WAXS), and dynamic mechanical analysis (DMA). X-ray scattering patterns revealed clay intercalation and TEM showed dispersion with partial delamination. The loss modulus peak broadened with clay content, while Tg remain constant. Montmorillonite reinforced the rubber. The DMA exhibited non-linear behaviour typified as a Payne effect (see Section 20.11) that increased with clay content and was more pronounced for this type of nanocomposite. Viscoelastic behaviour was observed under large strains via recovery and stress relaxation. ... 

Dong XM, Revol J-F, Gray DG (1998) Effect of microcrystallite preparation conditions on the formation of colloid crystals of cellulose. Cellulose 5 19-32 Dubief D, Samain E, Dufresne A (1999) Polysaccharide microcrystals reinforced amorphous poly (beta-hydroxyoctanoate) nanocomposite materials. Macromolecules 32 5765-5771 Dufresne A (2000) Dynamic mechanical analysis of the interphase in bacterial polyester/cellulose whiskers natural composites. Compos Interfaces 7 53-67 Dufresne A (2006) Comparing the mechanical properties of high performance polymer nanocomposites from biological sources. J Nanosci Nanotechnol 6 322-330 Dufresne A, Vignon MR (1998) Improvement of starch film performances using cellulose microfibrils. Macromolecules 31 2693-2696... 

Crystallinity of PLA has a strong impact on its mechanical properties. Suryanegara et al. have prepared PLA/MFC nanocomposites in both fully amorphous and crystallized states. The tensile modulus and strength of pristine PLA were improved with an increase of MFC content in both amorphous and crystallized states. Dynamic mechanical analysis (DMA) has been used to study the effect of MFC reinforcement on the thermomechanical properties of PLA in both states and the results are shown in Figure 9.5. In the amorphous state, the storage modulus of pristine PLA below Tg is almost constant at around 3 GPa. Above Tg, the modulus drops to 4 MPa at 80 °C, and then increases to 200 MPa at 100 °C owing to the cold... 

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... 

Both experimental and theoretical studies indicate the influence of nanoparticles boundary interactions on the dynamics of polymers within an interfacial layer because the size of nanometer particles is comparable to the relative size of a single polymer chain [44,45]. The degree of interaction between the nanoparticles and matrix polymer can be estimated from dynamic mechanical analysis (DMA) of PP and its nanocomposites using... 

Using a nanoindentation technique, Shen et al. [150] studied the effects of clay concentrations on the mechanical properties (hardness, elastic modulus, and creep behavior) of exfoliated polyamide 6,6-clay nanocomposites. The results were discussed in conjnnction with those obtained by dynamic mechanical analysis and optical microscopy, and also conjunction with changes in morphology, crystallinity, and x-ray diffraction. 

Static and Dynamic Mechanical Analysis of Coir Fiber/Montmorillonite Nanoclay-Filled Novolac/Epoxy Hybrid Nanocomposites... 

Hazarika A, Maji TK (2014c) Strain sensing behavior and dynamic mechanical properties of carbon nanotubes/nanoclay reinforced wood polymCT nanocomposite. Chem Eng J 247 33-41 Hazarika A, Maji TK (2014d) Thermal decomposition kinetics, flammability, and mechanical property smdy of wood polymtar nanocomposite. J Therm Anal Calorim 115 1679-1691 Hazarika A, Mandal M, Maji TK (2014) Dynamic mechanical analysis, biodegradability and thermal stability of wood polymer nanocomposites. Compos Part B 60 568-576 Hetzer M, Kee D (2008) Wootl/polymer/nanoclay composites, environmentally friendly sustainable technology a review. Chem Eng Res Des 86 1083-1093 Hill CAS, Abdirl KHPS, Hale MD (1998) A study of the potential of acetylation to improve the properties of plant fibres, frrd Crops Prod 8 53-63 Hoffmann MR, Martin ST, Choi WY, Bahnemann W (1995) Environmental application of semiconductm photocatalysis. Chem Rev 95 69-96 Huda MS, Drzal LT, Misra M, Mohanty AK (2(K)6) Wood-fiber-reinforced poly(lactic acid) composites evaluation of the physicomechanical and morphological properties. J AppI Polym Sci 102 4856-4869... 

The mechanical properties of the bulk PET and its nanocomposites were measured by tensile testing on injection-molded microtensile dogbones (ASTM-D638, Type IV) and by dynamic mechanical analysis (DMA) on injection-molded bars. 

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