Differential scanning calorimetry heating

Heat Treatment of AuSn Particles. Differential Scanning Calorimetry. Heat treatment of these ultra-fine particles caused the expected increase in crystallite... 

Figure 36 shows differential scanning calorimetry heating traces comparing films processed identically from select solutions in Fig. 35. It can be observed that the sample containing only PDMS + PS shows evidence of a Tm at -39°C due to the PDMS, whereas the sample containing star + PDMS + PS does not show a Tm in this region due to the PDMS. This leads to the notion that the PDMS is molec-ularly dispersed and not able to crystallize, which is a result of the PDMS being...

FIGURE 4.1 Differential scanning calorimetry heating and cooling curves of glyceryl tri-palmitate (Dyn 116) bulk material, with microparticles prepared by solvent evaporation and microparticles prepared by melt dispersion 1 d after the preparation. The plots are displaced vertically for better visualization. (Adapted from [13] with permission from Elsevier.)... 

Differential Scanning Calorimetry Heats of Solution Refractive Index Surface Tension Viscosity... 

Fitting Differential Scanning Calorimetry Heating Curves for Polyetherimide Using a Model of Structural... 

Fig. 8 Differential scanning calorimetry heating curves of PBS crystallized at different temperatures, a PBS with about 2.5 x 10 (Yasuniwa et al. 2005), b PBS with about 6,800 (Papageorgiou and Bikiaiis 2005)...

DSC (differential scanning calorimetry) Heat capacity versus temperature or time allows measurement of heats of fusion, identification of crystalline and liquid crystalline phases, degrees of crystallinity, etc. Glass transition measurement allows characterisation of ageing, blend compatibilities. Heats of reaction allow cure and degradation studies. 

FIG. 10 Differential scanning calorimetry heating thermograms of compositions (Fig. 9). Heating rate = 10°C/min. 

Differential Scanning Calorimetry. Heat produced by the inteidiffusion and crystallization of the multilayer reactants was quantified using differential scanning calorimetry. Approximately 1 mg of sample free of the substrate was used. These samples were obtained by first coating a three inch silicon wafer with polymethylmethacrylate (PMMA) using a 3% solution in chlorobenzene deposited by spin coating at 1000 rpm. The desired multilayer structure was then deposited upon the PMMA coated substrate. After the sample was removed from the chamber, it was immersed in acetone, which dissolved the PMMA, causing the multilayer film to float off of the substrate. Typically, the films broke up and rolled into many small pieces, which were collected via sedimentation into an aluminum DSC pan. The sample was dried under reduced pressure to remove residual acetone. Finally the pan was crimped closed. 

Fig. 5. Differential scanning calorimetry thermogram. Amorphous PPS is heated from room temperature to 325°C at 20°C/min.

Fig. 10. Differential scanning calorimetry of cellulose triacetate. Second heating at 20°C/min. glass-transition (T temperature = 177 " C crystallization on heating (T)/j) = 217 C melting temperature (Ta) = 289 C. To convert to cal, divide by 4.184.

From differential scanning calorimetry (dsc) data from Technochemie GmbH—Verfahrenstechnik. Heating rate = 10° C/min ... 

Fig. 10. Differential scanning calorimetry thermogram of a thermoset. The reaction order is 1.83, = 95 kJ/mol (22.7 kcal/mol), and the heat of...

Differential scanning calorimetry (DSC) Onset temperature of exotherms, heat of reaction... 

The procedures of measuring changes in some physical or mechanical property as a sample is heated, or alternatively as it is held at constant temperature, constitute the family of thermoanalytical methods of characterisation. A partial list of these procedures is differential thermal analysis, differential scanning calorimetry, dilatometry, thermogravimetry. A detailed overview of these and several related techniques is by Gallagher (1992). 

Difl erential thermal analysis (DTA) and differential scanning calorimetry (DSC) are the other mainline thermal techniques. These are methods to identify temperatures at which specific heat changes suddenly or a latent heat is evolved or absorbed by the specimen. DTA is an early technique, invented by Le Chatelier in France in 1887 and improved at the turn of the century by Roberts-Austen (Section 4.2.2). A... 

Common examples of the high Tg macromers are based on polystyrene or polymethylmethacrylate (PMMA) polymers of sufficiently high molecular weight to have a high T (typically on the order of 70-100°C as measured by differential scanning calorimetry) and also to make them immiscible with the acrylic polymer backbone once the solvent or heat has been removed. Typical molecular weight of the polystyrene or PMMA macromers is on the order of 5000-10,000 Da. Their generic structure can be pictured as in Fig. 13 (shown there for polystyrene). 

The various terms appearing in these equations are self-evident. The differential heat release, dkidt, data are computed from differential scanning calorimetry (DSC). A typical DSC isotherm for a polyurethane reactive system appears in Fig. 11. Energetic composite processing is normally conducted under isothermal conditions so that Eq. (15) is more applicable. 

The techniques referred to above (Sects. 1—3) may be operated for a sample heated in a constant temperature environment or under conditions of programmed temperature change. Very similar equipment can often be used differences normally reside in the temperature control of the reactant cell. Non-isothermal measurements of mass loss are termed thermogravimetry (TG), absorption or evolution of heat is differential scanning calorimetry (DSC), and measurement of the temperature difference between the sample and an inert reference substance is termed differential thermal analysis (DTA). These techniques can be used singly [33,76,174] or in combination and may include provision for EGA. Applications of non-isothermal measurements have ranged from the rapid qualitative estimation of reaction temperature to the quantitative determination of kinetic parameters [175—177]. The evaluation of kinetic parameters from non-isothermal data is dealt with in detail in Chap. 3.6. 

Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are also very useful tools for the characterization of polymers. TGA and DSC provide die information about polymer stability upon heating and thermal behaviors of polymers. Most of the polymers syndiesized via transition metal coupling are conjugated polymers. They are relatively stable upon heating and have higher Tgs. 

In differential scanning calorimetry (DSC), higher precision can be obtained and heat capacities can be measured. The apparatus is similar to that for a DTA analysis, with the primary difference being that the sample and reference are in separate heat sinks that are heated by individual heaters (see the following illustration). The temperatures of the two samples are kept the same by differential heating. Even slight... 

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