Differential scanning calorimetry (DSC) is a thermoanalytical technique that measures the heat flow into or out of a sample as it is heated, cooled, or held at constant temperature. A DSC instrument consists of a sample pan and an empty reference pan that are heated or cooled at a controlled rate. It detects transitions in materials, such as glass transitions, melting points, and crystallization events, by measuring the heat differential between the sample and reference. There are three main types of DSC instruments: power-compensated DSC, heat-flux DSC, and modulated DSC. DSC is widely used to characterize polymers and analyze their thermal transitions.

1. Differential Scanning
Calorimetry
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PREPARED BY: Hamza Suharwardi
ROLL NO: MM-03

2. Definitions
• A calorimetermeasures the heat into or out of a
sample.
• A differential calorimeter measures the heat of a
sample relative to a reference.
• A differential scanning calorimeter does all of the
above and heats the sample with a linear temperature
ramp.
• Endothermicheat flows into the sample.
• Exothermicheat flows out of the sample.
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3. • Differential Scanning Calorimetry (DSC) measures the
temperatures and heat flows associated with transitions in
materials as a function of time and temperature in a
controlled atmosphere.
• These measurements provide quantitative and qualitative
information about physical and chemical changes that
involve endothermic or exothermic processes, or changes
in heat capacity.
DSC: The Technique
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4. Schematic of DSC
Instrument
Thermocouple
Sample Reference
Thermocouple
T1 T2
heater heater
Low mass
1 gram
DW
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5. Differential Scanning Calorimetry (DSC)
Exothermal
dQ/dT
Temperature
 DSC measures differences in the amount of heat required to
increase the temperature of a sample and a reference as a
function of temperature

6. 99
Sample Preparation : Shape
• Keep sample as thin as possible (to minimise thermal
gradients)
• Cover as much of the pan bottom as possible
• Samples should be cut rather than crushed to obtain a
thin sample (better and more uniform thermal contact
with pan)
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7. Other DSC techniques
These are three different types of DSC
instruments.
1. Power-compensated DSC
2. Heat-flux DSC
3. Modulated DSC
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8. Power-compensated DSC
 In this case, the sample and reference material are
heated separately and continuously maintained at same
temperature.
 While both temperatures are increased or decreased
linearly.
 The differential power is recorded as a function of
temperature and the peak area represents the energy of
transition.
 The difference in electrical power needed to maintain
equal temperature is measured.
 This DSC has lower sensitivity and capable of higher
resolution than heat-flux DSC.
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9. POWER-COMPENSATED
DSC
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10. Heat-flux DSC instrument
 In this case, the difference in heat flow into
the sample and reference is measured while
the sample temperature is changed at a
constant rate.
 Both sample and reference are heated by a
single heating unit.
 The differential heat flow to the sample and
reference is monitored by chromel-
constantan area thermocouples.
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11. HEAT-FLUX DSC 11

12. Technical Group Talk
DSC: Main Sources of Errors
•Calibration
•Contamination
•Sample preparation – how sample is loaded into a pan
•Residual solvents and moisture.
•Thermal lag
•Heating/Cooling rates
•Sample mass
•Processing errors
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13. Applications of DSC
 Using this technique it is possible to observe fusion
and crystallization events as well as glass transition
temperatures (Tg).
 DSC can also be used to study oxidation, as well as
other chemical reactions.
 DSC is used widely for examining polymeric materials
to determine their thermal transitions. Important
thermal transitions include the glass transition
temperature (Tg), crystallization temperature (Tc), and
melting temperature (Tm).
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14. Any questions?
You can find me at:
hamzaahmed0696@gmail.com
https://www.researchgate.net/profile
/Hamza-Suharwardi-2
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