Differential Scanning Calorimetry (DSC) Sample Testing

Differential Scanning Calorimetry (DSC) Sample Testing

Differential scanning calorimetry (DSC) the difference in heat flow between sample and reference sensors is measured as a function of temperature. DSC can be used to study phase transitions such as melting, crystallization, cold crystallization or glass transition, and heat capacity. This versatile thermal analysis technique may be used to study cure and crystallization kinetics, and to determine material purity. It provides information on processing effects and material fingerprinting characteristics. We have several DSC techniques offered.

These include:
Standard DSC
Pressure DSC
Modulated DSC
Standard DSC

Our DSC units are configured to operate over a temperature range from -170°C to 600°C, although measurements over 600 C may be performed. Samples may be solids or liquids. We have different pan types are available: aluminum, hermetic, graphite, and copper.


Material fingerprinting
Phase transition definition, including:
Melting point
Glass transition
Curie point
Crystallization
Phase diagrams
Mesophase transitions including liquid crystals
Melting point depression analysis
Heat of fusion
Degree of crystallinity
Curing
Cure kinetics
Avrami kinetics for crystallization
Decomposition analysis
Purity determination
Pressure DSC (PDSC)

Pressure DSC, measure differences in heat flow between sample and reference sensors at increased pressure. Useful for studying decomposition and oxidative stability. Analysis can be done in ramping mode to determine the oxidation onset temperature or isothermally to determine the oxidation induction time. We can accommodate pressures up to 1000 psi under nitrogen or oxygen, with operation from ambient temperature to 600°C. Other gases can be used such as carbon dioxide. Under pressure boiling points may be elevated above decomposition points.

PDSC is useful in studying:

Oxidative stability
Oxidative onset time (OOT)
Oxidative induction time (OIT)
Decomposition
Modulated DSC (MDSC)

Modulated DSC (MDSC) allows the separation of complex overlapping thermal events that may occur in the heat flow. This is accomplished by imposing a temperature sine wave on a standard linear or isothermal temperature program to decouple the response that is rate dependent from the total conventional heat flow response. The response that is not rate dependent can be determined by subtraction of the rate dependent response from the total heat flow. The total sample responses is thus separated into two components:

Reversing
Non-reversing
The reversing or rate dependent component includes events that are related to the heat capacity, such as the glass transition. Use of MDSC can be used to isolate the glass transition even when it is complicated by other overlapping thermal events, for example to identify:

Glass transition obscured by an aging peak
Glass transition separated from a cure exotherm, primarily for epoxy cures
Glass transition followed by decomposition
The non-reversible component includes effects due to time dependent kinetic events. These include:

Polymer aging
Loss of solvent or water
Cold crystallization
Curing exotherm