Differential scanning calorimetry isothermal heat flow rate measurements

Differential Scanning Calorimetry (DSC) This is by far the widest utilized technique to obtain the degree and reaction rate of cure as well as the specific heat of thermosetting resins. It is based on the measurement of the differential voltage (converted into heat flow) necessary to obtain the thermal equilibrium between a sample (resin) and an inert reference, both placed into a calorimeter [143,144], As a result, a thermogram, as shown in Figure 2.7, is obtained [145]. In this curve, the area under the whole curve represents the total heat of reaction, AHR, and the shadowed area represents the enthalpy at a specific time. From Equations 2.5 and 2.6, the degree and rate of cure can be calculated. The DSC can operate under isothermal or non-isothermal conditions [146]. In the former mode, two different methods can be used [1] ... 

Calorimetric studies have depicted the impact of nanoparticles on isothermal curing of epoxy-amine system. Isothermal measurements done at 298 K using temperature-modulated differential scanning calorimetry are shown in Figure 9.15. The heat flow signal recorded during this measurement is directly proportional to the reaction rate of the curing process. It was foxmd that,... 

The term calorimetry denotes a variety of measurement methods which involve a measurement of the heat of physical or chemical changes in a sample. One of the most commonly used calorimetric methods is differential scanning calorimetry in which the difference in the heat flow rate to a primary sample and a reference sample is measured, when both are subjected to the similarly alternating temperature. Usually this is done in a specified, controlled atmosphere. In isothermal calorimetty the measurement temperature is kept as constant as possible, and, instead of temperature alternation, the other environmental parameters such as gas atmosphere, relative humidity, light exposure, etc., are alternated. 

In thermal analysis, physical parameters like mass, heat flow, heat capacity and enthalpy are measured as a function of temperature and time, while the sample is subjected to a controlled temperature programme (which in most cases is the application of linear heating rates or isothermal conditions).The two most common thermoanalytical techniques to investigate thermal and caloric properites of energy-rich compounds are Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). 

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