Composites storage modulus

Dynamic thermal mechanical analysis indicates significant broadening of glass transition temperature at or around PU/EP composition of 70/30. This is true for all three groups studied. At this composition, storage modulus showed much less steep variations with temperature during the transition from glassy to rubbery state. 

FIGURE 28.22 Storage modulus G vs temperature of carbon nanotube (CNT)/mbber composite. (From Lopez-Manchado, M.A. et al., J. Appl. Polym. Sci., 92, 3394, 2004.)... 

Experiments with the /3-lg/Tween 20 system were performed at a macroscopic a/w interface at a /3-lg concentration of 0.2 mg/ml [40]. The data obtained relate to the properties of the interface 20 minutes after formation. Up to R = 1, the storage modulus (dilational elasticity) was large and relatively constant, whereas the loss modulus (dilational viscosity) increased with increasing R. As R was increased to higher values there was a marked decrease in the storage modulus (dilational elasticity) and a gradual increase in the loss modulus (dilational viscosity). In summary, the data show the presence of a transition in surface dilational behavior in this system at a solution composition of approximately R = 1. At this point, there is a transformation in the adsorbed layer properties from elastic to viscous. 

Fig. 4 Temperature dependence of the dynamic storage modulus E and loss modulus E" for CELL/PACMO composites. (Reproduced from [72])...

Fig. 15. Dynamic mechanical analysis of 100 minutes-aged Thornel 300/Fiberite 934 composite showing the loss tangent and the dynamic storage modulus...

Fig. 16. Influence of physical aging time on the dynamic storage modulus of Thornel 300/Fiberite 934 composites...

The pronounced amplitude dependence of the complex modulus, referred to as the Payne effect, has also been observed in low viscosity media, e.g., composites of carbon black with decane and liquid paraffin [50], carbon black suspensions in ethylene vinylacetate copolymers [51], and clay/water suspensions [52, 53]. It was found that the storage modulus decreases with... 

Fig. 32 a Time development of the small strain storage modulus of uncross-linked S-SBR composites with 50 phr N234 during heat treatment at 160 °C for various molar masses, as indicated (0.28% strain, 1 Hz), b Strain dependency of the storage modulus of the samples depicted in a after heat treatment for 60 min at 160 °C... 

Fig. 39 Double logarithmic plot of the small strain storage modulus vs filler volume fraction for a variety of carbon black filled composites, as indicated. The solid lines with slope 3.5 correspond to the prediction of Eq. (30). Data of butyl/N330 composites are taken from [28] (compare Fig. 2a)...

Fig. 42 Strain dependency of the storage modulus at 20 °C of cross-linked S-SBR- and EPDM composites filled with 50 phr N220 and graphitized N220g, respectively...

Figure 8 presents the storage and loss-modulus master curves obtained on all five samples of interest. The dashed lines indicate extensions of the master curves, using appropriately reduced data from the Rheovibron experiments in tension. Storage-modulus data in the rubbery plateau region vary systematically with composition, i.e., the... 

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