Dynamic mechanical analysis . See

Probably the most convenient and most widely used methods arc specific heat using DSC (see Section 2 in this chapter and Section 5 in Chapter 24) and dynamic mechanical analysis (see Chapter 21). However, a range of methods have been tried and reported on in the literature, from volume change to refractive index. For rubbers a measure can be obtained from the low temperature tests discussed in Section 5, Practically, the glass... 

Tackifier resins are generally brittle amorphous materials with high softening temperatures (typically 40 -150 °C) [242], [243] and low molecular masses (some 10 to some 10 g/mol). Some are liquids that soften below ambient temperature. All should exhibit reasonable compatibility with the elastomer, which can be detected by the clearness of the mixtures or by dynamic mechanical analysis (see Chap. 2.2.2.). Corn-... 

Crystallization in a thermolropic liquid-crystalline polymer is again a process of nucleation and growth [54]. It has been shown that the process can be followed easily using dynamic mechanical analysis (see Chap. 12) [55], in which we measure the stress response of the material to an imposed small-amplitude sinusoidal shear strain. Differential scanning calorimeter (DSC) data on the kinetics of crystallization show that the process is describable by an Avrami equation [56]. 

Dynamic DSC, 409. See also Differential scanning calorimetry (DSC) Dynamic mechanical analysis (DMA), 138, 163, 241-242, 407, 409... 

Mechanical properties. See also Dynamic mechanical analysis (DMA) of polyamides, 138 of polyester LCPs, 52 of polyurethanes, 242-244 of semicrystalline aromatic-aliphatic polyesters, 45 Mechanical recycling, 208 Medical applications, for polyurethanes, 207... 

The measurements of Young s modulus in dependence of the temperature (dynamic-mechanical measurements, see Sect. 2.3.5.2) and the differential thermal analysis (DTA or DSC) are the most frequently used methods for determination of the glass transition temperature. In Table 2.10 are listed and values for several amorphous and crystalline polymers. 

The physical properties of barrier dressings were evaluated using the Seiko Model DMS 210 Dynamic Mechanical Analyzer Instrument (see Fig. 2.45). Referring to Fig. 2.46, dynamic mechanical analysis consists of oscillating (1 Hz) tensile force of a material in an environmentally (37°C) controlled chamber (see Fig. 2.47) to measure loss modulus (E") and stored modulus (E ). Many materials including polymers and tissue are viscoelastic, meaning that they deform (stretch or pull) with applied force and return to their original shape with time. The effect is a function of the viscous property (E") within the material that resists deformation and the elastic property (E )... 

Baer, Hiltner, and colleagues (see Hiltner, 1979, and references cited therein) have used dynamic mechanical analysis to examine the hydration of collagen, elastin, and several polypeptides. A torsional pendulum constructed of the sample was examined for low-frequency (i.e., IHz) mechanical loss as a function of hydration and temperature. A common feature is a dispersion that is absent in the dry protein and appears at... 

Pellicle and tea-immersed pellicle were analyzed using nanoDMA (dynamic mechanical analysis) to see if the tannins had an effect on the viscoelasticity of the pellicle. NanoDMA is a technique used to study and characterize mechanical properties in viscoelastic materials. The method is an extension of nanoindentation testing [58, 59], An analysis of the nanoindentation load-depth curve gives the hardness (H) and reduced elastic modulus (E ), provided the area of contact, A, between the indenter tip and the sample is known [ 13]. By... 

It is important when conducting expensive test programmes that the constituents be checked for quality prior to use and that the fabricated materials be checked after manufacture, or on receipt if already fabricated. The techniques used vary from the Barcol hardness test (see below) to the more rigorous DMA (dynamic mechanical analysis ISO 6721 (ten parts) [14]) or DSC [differential scanning calorimetry ISO 11,357 (7 parts) [15]) test methods. There is some concern that these tests do not give the same values due to subtle variations between different manufacturers equipment. 

Gelation of plasticized polymers can be conveniently observed by a dynamic mechanical analysis and microscopy (see more on this subject in Chapter 9). Aggregation and formation of clnsters in solntion can be followed by a dynamic light scattering experi-... 

Quasi-isothermal TMDMA data for PEN are shown in Fig. 6.51 for slow cold crystallization at 418 K [42]. The method consists of dynamic mechanical analysis, DMA (see Sect. 4.5.4), to which temperature modulation was added. The insert is a... 

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