Polystyrene loss modulus

Figure 5.20 A comparison of the storage and loss modulus obtained from an experiment for a polystyrene latex (points) with the spectra (Figure 5.19) calculated using Equation (5.59)...

Fig. 5.9. Loss modulus vs frequency for narrow distribution polystyrene melts (124). See Fig. 5.8. [Reproduced from Macromolecules 3,112 (1970).]...

Fig. 5.10. Loss modulus vs frequency for a narrow distribution polystyrene melt reduced to...

FIGURE 10.19 Dynamic mechanical thermal analysis of a block copolymer of SBR rubber and polystyrene. This illustrates two phases however, owing to the broad loss modulus peak, it may be assumed that some mixing has occurred in the polystyrene phase. (Reprinted from Wetton, R.E. et al., Thermochim. Acta 175, 1, 1991. With permission.)... 

The measured G and G" (or equivalently rj and 77") values, as a function of the frequency w, can be displayed as a spectrum — the viscoelastic spectrum. Figures 4.9 and 4.10 show the storage modulus spectra G lo) and the loss modulus spectra G" oj), respectively, of a series of nearly monodisperse polystyrene samples. 

FIG. 4. Loss modulus of TR 41-1649, with 0.482 polystyrene. Data symbols and lines are the same as in Fig. 3. Major differences are apparent between the three types of interphases incorporated in the model. The linear profile is approximately correct in the mid-range but deficient as the peaks are approached, while the sharp interface case is an extremely poor predictor over the entire interpeak region. 

FIG. 8 (bottom). Loss modulus of TR 41-1647, with 0.268 polystyrene. Data symbols and lines correspond to those in Fig. 7. The linear composition profile is here most deficient in the plateau midrange, and the no-interphase assumption is entirely in error. 

Fig. 45 Master curves of loss modulus G" plotted against frequency coat a reference temperature of200°C for CaCOj-filled polystyrenes. The contents of CaC03 particles are 0, 20, 40 and 60wt.%. (From Ref. 48.)...

Breadth of relaxation process even for a monodis-perse polymer loss modulus versus log frequency for a narrow distribution polystyrene melt reduced to 160 C (W , = 21,500). The dashed line is an approximate resolution of the terminal relaxation peak. The constructed line (— - —) is G" versus cu calculated from the Rouse model. From Graessley (1974). 

Yahlon DG, Proksch R, Gannepalli A, Tsou AH. Mapping storage modulus and loss modulus of polyolefin/polystyrene hlends with atomic force microscopy. Rubber Chem Technol 2012 85 559. 

Figure 13.16 Loss modulus of polystyrene in di-2-ethylhexylphthalate for solutions of a 411 kDa polymer at 0.225 wt% ( ), 411 kDa at 0.332 wt% (A), 860 kDa at 0.332 wt% (0), and (displaced upward 100-fold for comparison with next figure) 160 kDa at 0.332 wt% (O), using data of Wolkowicz and Forsman(27).

Figure 13.17 Loss modulus of 160 kDa polystyrene, 0.33 wt%, same data and fits as previous figure, plotted as G" co) rather than G" co)lci>.

Figure 6.15 Comparison of the predictions of the double reptation model (lines) to experimental data (symbols) for (a) the storage modulus G, and (b) the loss modulus G", for bidisperse polystyrenes (MW = 160,000 and 670,000) at 160 °C [35]. The volume fractions of the high molecular weight component ((j ) from right to left are 0.0,0.05,0.1,0.2, and 0.5, and 1.0, respectively.The parameter values are G 5 = 2 10 Pa and /f = 4.6 10 s/(mol) " The latter value, obtained by a best fit to the data for monodisperse samples, is almost identical to the value (K = 4.55 -10" s/(mol) ) obtained using Eq. 7.3 with =0.00375. Adapted from Pattamaprom and Larson [19].

Figure 6.17 (a) Comparison of the predictions of the dual constraint model (solid lines) and the double reptation model (broken lines) to experimental data (symbols) for the storage modulus, G, and the loss modulus, G", for monodisperse linear polystyrene (M = 363,000) at 150 °C. The parameter values are G 5 = 2 -10 Pa.and = 0.05 s,the latter value being obtained as a best fit. From this value of Tg,after multiplying it by the correction factor ofO.375 in footnote (g) of Table 7.1, the value K = 2.275 10" s/(mol) for the double reptation model is obtained from Eq. 7.3 (from Pattamaprom and Larson [19]).(b)The same as (a), except the sample is a polydisperse polystyrene M = 357,000 = 2.3) constructed from 11... 

SBM) as a compatibilizer. As a result of the particular thermodynamic interaction between the relevant blocks and the blend components, a discontinuous and nanoscale distribution of the elastomer at the interface, the so-called raspberry morphology, is observed (Fig. 15). Similar morphologies have also been observed when using triblock terpolymers with hydrogenated middle blocks (polystyrene-W<9ck-poly(ethylene-C0-butylene)-Wock-poly(methyl methacrylate), SEBM). It is this discontinuous interfacial coverage by the elastomer as compared to a continuous layer which allows one to minimize the loss in modulus and to ensure toughening of the PPE/SAN blend [69],... 

The dynamic viscoelasticity and the thermal behaviour of films of Thermoelastic 125 cast from solutions in four solvents - toluene (T), carbon tetrachloride (C), ethyl acetate (E), and methyl ethyl ketone (M) — have been studied by Miyamato133 The mechanical loss tangent (tan 8) and the storage modulus E dependences exhibit two transitions at —70 °C and 100 °C which have been attributed to onset of motion of polybutadiene and polystyrene segments, respectively. The heights of the polybutadiene peaks on tan 6 curves decrease in the order C > T > E > M, while for polystyrene the order is reversed C < T < E < M. These phenomena have been related to the magnitude of phase separation of the polystyrene and polybutadiene blocks. 

Dynamic Mechanical Properties. Figure 15 shows the temperature dispersion of isochronal complex, dynamic tensile modulus functions at a fixed frequency of 10 Hz for the SBS-PS specimen in unstretched and stretched (330% elongation) states. The two temperature dispersions around — 100° and 90°C in the unstretched state can be assigned to the primary glass-transitions of the polybutadiene and polystyrene domains. In the stretched state, however, these loss peaks are broadened and shifted to around — 80° and 80°C, respectively. In addition, new dispersion, as emphasized by a rapid decrease in E (c 0), appears at around 40°C. The shift of the primary dispersion of polybutadiene matrix toward higher temperature can be explained in terms of decrease of the free volume because of internal stress arisen within the matrix. On the other... 

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