Glass transition data

Additional information on elastomer and SAN microstmcture is provided by C-nmr analysis (100). Rubber particle composition may be inferred from glass-transition data provided by thermal or mechanochemical analysis. Rubber particle morphology as obtained by transmission or scanning electron microscopy (101) is indicative of the ABS manufacturing process (77). (See Figs. 1 and 2.)... 

Thermal Properties. Spider dragline silk was thermally stable to about 230°C based on thermal gravimetric analysis (tga) (33). Two thermal transitions were observed by dynamic mechanical analysis (dma), one at —75° C, presumed to represent localized mobiUty in the noncrystalline regions of the silk fiber, and the other at 210°C, indicative of a partial melt or a glass transition. Data from thermal studies on B. mori silkworm cocoon silk indicate a glass-transition temperature, T, of 175°C and stability to around 250°C (37). The T for wild silkworm cocoon silks were slightly higher, from 160 to 210°C. 

Glass transition data for copolymers and terpolymers of controlled and uncontrolled composition are shown in Figures 6 and 7. The Tg s calculated using the equations 7 and 8 of Fox (12) and Woods (13) have been used with the following hompolymer Tg s methyl methacrylate, 108°C tributyltin methacrylate, 0°C 2-ethylhexyl acrylate, -50"C (14-16) are also shown. 

FIGURE 6. Glass transition data for homogeneous TBTM-MMA Copolymers at different compositions. 

QO2— ). Glass transition temperatures (Tg s) of copolymers I and IV were determined by the use of a differential scanning calorimeter. The samples were heated at 10 C/minute In air, to 200 C, then cooled and reheated. Glass transition data was taken from the "second heating". 

Selecting Damping Materials from Differential Scanning Calorimetry Glass-Transition Data... 

Table 10-2. Visible spectroscopic, molecular weight, and glass transition data for poly(ferrocenyl-silanes) 39 (adapted from [48 a])...

Molecular Weight and Glass Transition Data for POLY(FERROCENYLGERMANES) 20... 

Schematic of range of glass transition data for low moisture cereal foods and their major components (starch, amylopectin, gluten).

In Figure 21.5, the self-detachment conditions for aqueous solutions of the maltodextrin MOR-REX 1910 and sucrose at 5, 10, and 15% (dwb) are compared with the glass-transition curves calculated using the expanded Gordon-Taylor model (Roos, 1993). The self-detachment of the dried films of aqueous solutions of the maltodextrin MOR-REX 1910 and sucrose followed the same pattern of decreasing moisture content of the material with an increase in temperature as observed with the glass-transition data. This process occurred in a temperature range of 20°C below Tg, for 5,10, and 15% sucrose concentrations, as was observed by Collares et al. (2004) for maltodextrin MOR-REX 1910 without the addition of sucrose. 

Differential scarming calorimetry (DSC) was used to measure the glass transition (Tg) of samples humidified over saturated solutions of LiCl, CH3COOK, MgCl2, and K2CO3. The Gordon-Taylor equation was fitted to the glass-transition data. 

An analysis of the temperature dependence of the a transition revealed, as expected, adherence to the WLF theory (22,29,30). That is, Arrhenius plots of the glass transition data were not linear, and the data fit the WLF equation ... 

Figure 7.72 illustrates a large number of glass transition data of polymer solutions with comparisons to the Gibbs-DiMarzio (DM), Fox (F), and Schneider (S) equations described in Fig. 7.69 [30]. The upper left displays two sets of literature data on poly(vinylidene fluoride)-poly(methyl methacrylate) solutions (B,A). The glass transition shows a positive deviation from simple additivity of the properties of the pure components, which can only be represented with the help of the indicated interaction parameters of the Schneider equation. The lower left set of data illustrates poly(oxyethylene)-poly (methyl methacrylate) solutions (, o). They are well described by all three of the equations, indicating rather small specific interactions and great similarity between volume and entropy descriptions.

Fig. 12.17 Dielectric loss versus frequency at 270 K for the PVE/PI blend at a composition of 50 % PVE/50 % PI. Circles, pure PVE squares, pure PI stars, blend PVE/PI. Lines are estimated contributions of the dynamic glass transition (Data were taken from reference Arbe et al. (1999))...

Glass-transition data determined by DSC were similar to but slightly different from dynamic mechanical data. As-cast samples at high SAN contents and with no PCL crystallinity showed very similar single, composition-dependent TgS by both techniques. At higher PCL contents (30-70%, approximately), as-cast samples showed a constant Tg ( 50 °C) by dynamic mechanical analysis these data describe blends with combinations of different proportions of crystalline PCL... 

Figure 4. Mass density of PEI as a Junction of the dissolved amount of CO2 and the foaming temperature. Numbers written close to the straight lines represent the mass density ofthe foam in g/cm. The mass density contours are constructed by linear interpolation from e q>erimental data series of nine different saturation pressures, equally distributed over the investigated concentration range. The glass transition temperature (T and are presented defendant on the dissolved amount of CO2. The straight line represents a least-squares JU of die ejqierimental glass transition data.

Fig. 5.15. Storage shear moduli measured for a series of fractions of PS with different molecular weights in the range M = 8.9 10 to M = 5.81 10. The dashed line in the upper right corner indicates the slope corresponding to the power law Eq. (6.81) derived for the Rouse-model of the glass-transition. Data from Onogi et...

Glass transition data for the commercially available Biopol polymers is shown in Fig. 5.3. Increasing the HV incorporation leads to small reduction in the copolymer 7g. 

Over 10000 papers contain glass transition data (43). This section of Polymer Handbook represents a fraction of these... 

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