Young temperature dependence

The temperature dependence of the yield stress, ay, of PMMA obtained at a strain rate, s = 2 x 10-3 s-1, is shown in Fig. 18. A sigmoidal curve is observed, which looks like the temperature dependence of the Young s modulus, E. When increasing the strain rate a similar behaviour is observed. 

As for PMMA, it is interesting to check to what extent ay is controlled by the Young s modulus, E. The temperature dependence of the ratio ay/E is... 

As the temperature of an amorphous polymer is lowered, there is a transition from rubberlike material with a low Young s modulus to a stiff glass with a high modulus. For example, the Young s modulus of PVC (measured at 1 s) increases from 0.15 to 1.2 GPa as the temperature is decreased from 90 to 75 °C. The glass transition temperature is in this range. The exact temperature depends on the rate of cooling. 

Figure 11-1. Temperature dependence of the partitioning of benzene (5) between water (w) and //-alkanes (a) of different chain lengths octane ( ), decane ( ), dodecane (A), tetradecane (H), and hexadecane (O)-In (C), die left vertical scale pertains when Flory—Huggins theory is applied to both die a and w phases, whereas die right vertical scale pertains when Rory—Huggins theory is applied only to die a phase. The figure is taken from de Young and Dill [ 17] with permission...

Young KM, Wrighton MS. Temperature dependence of the oxidative addition of triethylsilane to photochemically generated ( 5-C5Cl5)Mn(CO)2. Organometallics 1988 8(4) 1063-1066. 

The potential diagram for NO is shown in Figure 1.8. Baulch et al. [112] have recently reviewed the rate data and recommend a value for the third-order rate constant for recombination at 298°K with N2 as the third body of 1.03 x 10 32 cm6/molecule2-sec. The /8 (2f2II-X2n), y (A 2 +-X 2I I), d (C ari—A 2TI), and Ogawa (b 4S -a 4II) bands have all been identified in the complex chemiluminescence that accompanies the recombination. Young and Sharpless [113, 114] determined the total intensities of the first three of these systems at room temperature, and the temperature dependences of these processes have since been measured by Gross and Cohen [115]. 

Young [56] described a somewhat different pattern of kinetic behaviour for decomposition of the same salt. Again, there was an initial reaction of a surface impurity (about 2%) by a first-order process (f, = 121 kJ mol ). The subsequent acceleratory reaction, perhaps delayed by the initial process, was fitted by the power law (n = 3). This is attributed to the growth of a constant number of nuclei present at time, tg, and, because the nimiber of such nuclei is slightly temperature dependent, the value of E, for interface advance is 209 kJ moT . The mechanism of reaction was not developed fiulher. 

In 1967 B. H. Mahan and C. E. Young used a new microwave method to determine the rate constant for thermal electron attachment to molecules. These quantities were determined for SF6 and C7F14 using the ECD and agreed with the values reported using the microwave method at room temperature within the experimental error [37, 38]. In addition, the temperature dependence was determined so that activation energies were obtained. This was especially important in the case of strained molecules such as cyclooctatetrene [34],... 

The behaviour of elastic moduli of vitreous silica is also anomalous. The Young s modulus seems to continuously increase in the region of 100 to 1000 K. This has been understood on the basis of the experimentally observed extremely low values of thermal expansivity of vitreous silica. The modulus, M, can be treated as a function of any two thermodynamic variables M = M V, T) ox M = M(P, T). The temperature dependence of the modulus can therefore be written as,... 

First, the consolidation of polyimide and Cu was investigated to determine consolidation temperatures and pressures for the FGM formation. The most suitable consolidation temperatures are shown in Table 1. Densities, Young s modulus and thermal expansion coefficients are also listed in Table 1. Suitable consolidation temperatures depended on the pressure. Sintering was conducted and shrinkage of the samples were observed. The sintering temperature of Cu powders was at the point where shrinkage stopped. The density and modulus of Cu bodies were similar... 

The resonance frequency technique has been used for determining the adiabatic Young s moduli in dependence on test temperatures up to 1000 °C. The shear moduli were measured by the pulse-echo ultrasonic technique. The bulk moduli were determined by synchrotron radiation diffraction. The temperature-dependent Young s and shear moduli are plotted in fig. 7. 

The elastic moduli vs. temperature curves of the hypoeutectic Ti-Si7.5-All alloy and of the directionally solidified eutectic a-Ti-Ti5Si3 composite with discontinuous Ti5Si3 fibers -aspect ratio of lf/df 50- are depicted in fig. 14. In comparison the temperature-dependent Young s modulus of the polycrystalline Ti5Si3 compound is also shown in the diagram. A detailed description and discussion of the elastic moduli of the pure silicides is given in section 4.3. 

Table 6 Temperature dependence of Young s modulus for polycrystaUine alumina [2]...

Y. Seine, and S. Nagai, Temperature dependence of the Young s modulus of diamond thin film prepared by microwave plasma chemical vapour deposition, J. Mater. Sci. Lett., 12(5) 324-325 (1993)... 

Figure 9 shows the temperature dependence of the elastic part of the complex Young s modulus E a>) for various poly(vinyl methyl ether) hydrogel samples in water at a selected frequency of 20.1 rad/s. The polymer was cross-linked by electron beam irradiation (see Sect. 2.4, chapter Synthesis of hydrogels ). These data were compared with the temperature shrinking behaviour of sample PVME 20/80... 

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