Differential scanning calorimetric measurements

Thermogravimetric analysis (heating rate 10°C/min) of PPNA revealed that the polymer was stable to at least 220°C in an N2 atmosphere. (Figure 2) Differential scanning calorimetric measurements (heating rate 10°C/min) on several batches of PPNA indicated that Tg varied between 125-140°C. This variation may be a reflection of the amount of solvent (NMP) entrapped in the... 

Thermodynamic data of the epoxy polymerization with triphenylsulfonium salt photoinitiators can be obtained by differential scanning calorimetric measurements (DSC). Figure 6 shows the DSC diagram of the polymerization of Bisphenol-A di-glycidylether with triphenylsulfonium hexafluorophosphate, irradiation being carried... 

Fracture-Energy Testing. Table I gives the recipes and the fracture energies measured under slow and fast rates of test, for the elastomer-modified VER and for ETBN additions to the elastomer-modified VER. Also given are the total amounts of reactive liquid rubber, from both ETBN addition and CTBN reacted directly into the VER, for each recipe. For reference, the unmodified VER has a slow GIc. of 0.11 kj/m2. Finally, the Tg obtained from differential scanning calorimetric measurements is given for each recipe. 

HOhne GWH, Kurelec L (2001) Temperature-modulated Differential Scanning Calorimetric Measurements on Nascoit Ultra-high Molecular Mass Polyethylene. Thermochim Acta 377 141-150. 

Diketopiperazine-based dienes have also been polymerized by ADMET to form polyesters [89]. Dynamic light scattering and differential scanning calorimetric measurements indicated that these materials formed aggregates in Ar,AT-dimethylformamide, which is presumably due to the hydrogen bonding between diketopiperazine moieties. 

The change of the specific heat of the transition from amorphous solid to supereooled liquid as well as the temperature dependence of the specific heat in the amorphous solid and supercooled liquid has been examined for the La-Al-Ni amorphous alloys through detailed differential scanning calorimetric measurements (Inoue et al. 1989f). As an example, fig. 115 shows the thermograms of the amorphous La5sAl25Ni2o alloy with the widest supercooled liquid region. The Cp value of the as-quenched phase is 24 J/mol K... 

From differential scanning calorimetric measurements a marked cooling-heating cycle hysteresis has been observed, showing that water encapsulated in AOT reversed micelles is only partially freezable and that the freezable fraction displays marked supercooling behavior as a consequence of the very small size of the micellar core. The nonfreezable fraction has been identified as the water hydrating the AOT ionic heads [56,57]. 

Differential scanning calorimetric measurements have revealed well-defined thermal transitions which are well correlated with the observed optical transitions[29]. Temperature-dependent X-ray diffraction analyses have revealed a rather amorphous structure for this polymer that is not strongly affected by the heating process[2P]. 

Phase transformations have not been reported for aity of the rare earth tribromides, but only a few detailed studies of the high-temperature phase behaviour have been made. Brown et al. (1968) did not find evidence for polymorphism in GdBrs by X-ray diffraction Dworkin and Bredig (1971) none forLaBrs, CeBrs, PrBrs, NdBrs, GdBrs orHoBrs by drop-calorimetric measurements and Cordfunke et al. (Cordfunke and Blacquere, 1997 Cordfunke et al., 1999) none for NdBrs and DyBrs by differential scanning calorimetric measurements. 

Fig. 1.45. Schema of a differential scanning calorimetric (DSC) apparatus. Gerate DSC 821 . Temperature range with LN2 cooling -150 °C to 500 °C accuracy of temperature 0.2 °C resolution 0.7 gW in the measuring range of +/-350 mW cooling rate from +100 °C to -100 °C approx. 13 °C/min size of sample, several mg to 200 mg.

Measurements of glass transition temperatures at high pressure were made indirectly using, in particular, creep compliance [95, 96] or directly using differential scanning calorimetric techniques [97, 98]. The measured depression reaches values as high as 60°C for poly(methyl methacrylate) and polystyrene. 

The first directly-measured evidence that C—H bond rupture in the methyl group is the rate-determining step in the thermal de compn of TNT has been obtained with isothermal differential scanning calorimetric (DSC) analysis using deuterium isotope effects (Ref 96), DSC analysis has also been used to determine the kinetic parameters of thermal decompn (Ref 92). Others (Ref 101) have also studied the mechanism of the reaction using the deuterium isotope effect. Data are available on heat generation in... 

The dielectric relaxation of bulk mixtures of poly(2jS-di-methylphenylene oxide) and atactic polystyrene has been measured as a function of sample composition, frequency, and temperature. The results are compared with earlier dynamic mechanical and (differential scanning) calorimetric studies of the same samples. It is concluded that the polymers are miscible but probably not at a segmental level. A detailed analysis suggests that the particular samples investigated may be considered in terms of a continuous phase-dispersed phase concept, in which the former is a PS-rich and the latter a PPO-rich material, except for the sample containing 75% PPO-25% PS in which the converse is postulated. 

R)- and S- CHT A [Tf2N]" are liquid at room temperature, and results from differential scanning calorimetric (DSC) measurements indicate that they have glass transition temperature of -58.4°C. Results from thermal... 

In this work, we describe an automated differential scanning calorimetric (DSC) technique that can be used to measure polymerization kinetics for formation of urethane block polymers. The same technique is also used to measure phase separation during formation of polyurethane elastomers and the effect that separation has on the polymerization. The elastomer formulations consisted of modified liquid p,p -diphenyImethyl diisocyanate (MDI), 1,4-butanediol and an (oxypropylene-oxyethylene) macroglycol for the soft segment. 

Differential Scanning Calorimetric (DSC) Measurements of Soaked Pastes Cured at 90 °C... 

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