Differential Scanning Calorimetry crystallization temperature

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.

Birefringence measurements have been shown to be very sensitive to bimodality, and have therefore also been used to characterize non-Gaussian effects resulting from it in PDMS bimodal elastomers [5,123]. The freezing points of solvents absorbed into bimodal networks are also of interest since solvent molecules constrained to small volumes form only relatively small crystallites upon crystallization, and therefore exhibit lower crystallization temperatures [124—126]. Some differential scanning calorimetry (DSC) measurements on... 

The preparation of immiscible polymer blends is another way to disperse a bulk polymer into fine droplets. It has been reported for several polymers that when they are dispersed in immiscible matrices into droplets with average sizes of around 1 pm, they usually exhibit multiple crystallization exotherms in a differential scanning calorimetry (DSC) cooling scan from the melt (at a specific rate, e.g., 10 Cmin ). Frensch et al. [67] coined the term fractionated crystallization to indicate the difference exhibited by the bulk polymer, which crystallizes into a single exotherm, in comparison with one dispersed in a large number of droplets, whose crystallization is fractionated temperature-wise during cooling from the melt. 

The results of differential scanning calorimetry(DSC) indicate the change in aggregation state. The trans micelle showed a main endothermic peak at 14 2°C(A H =1.0 kcal/mol), corresponding to a gel-liquid crystal phase transition, whereas the transition temperature for the cis micelle appeared at 11.9°C( AH = 0.8 kcal/mol). This is unequivocal evidence that the trans-cis photoisomerization is a sufficient perturbation to alter the state of molecular aggregation. 

ISO 11357-3 1999 Plastics - Differential scanning calorimetry (DSC) - Part 3 Determination of temperature and enthalpy of melting and crystallization ISO 11357-7 2002 Plastics - Differential scanning calorimetry (DSC) - Part 7 Determination of crystallization kinetics... 

A glass transition (-75°C) and two broad bands close to 0°C are obtained b y differential scanning calorimetry performed at the cooling rate of 10°C/min from 20°C to -150°C followed by an isothermal at this temperature for 10 min and then heated to 30°C at the same rate. If the heating rate is lowered to 2 or 1 °C/min, a crystallization peak is obtained at 10°C. 

Crystallinity was determined using differential scanning calorimetry. About 5-10 mg of an experimental agent was heated from 25 to 200°C at a heating rate of 20°C/ minute. The sample was isothermed at 200°C for 1 minute and then cooled at a cooling rate of 20°C/minute to ambient temperature. Crystallization data represents peak temperatures of exotherms in the cooling cycle and are summarized in Table 1. 

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