Cooling scanning differential scanning calorimeterIt is a thermal analysis instrument that measures the relationship between the heat flux difference and temperature parameters between the reference end and the sample end,It is mainly used to measure various characteristic parameters during the heating or cooling process of substances, such as glass transition temperature Tg, oxidation induction period OIT, melting temperature, crystallization temperature, specific heat capacity, and enthalpy.

Main features:
1. New furnace structure, better resolution and baseline stability
2. Digital gas mass flowmeter, precise control of blowing gas flow rate, data directly recorded in the database
3. The instrument can adopt bidirectional control (host control, software control), with a friendly interface and easy operation

DSC software test chart

Sample Name: 1

Sample quality: 3.0mg

Heating rate: 5 ℃/min

Gas name: air

The differential scanning calorimeter can perform the following test items:

What is the glass transition temperature?

Glass transition is an inherent property of amorphous polymer materials (i.e. amorphous polymers), which is a macroscopic manifestation of the transformation of polymer motion forms. It directly affects the material's performance and processability, and has therefore been a major focus of polymer physics research for a long time.

The vast majority of polymer materials can typically exist in the following four physical states (or mechanical states): glassy state, viscoelastic state, high elastic state (rubber state), and viscous flow state. The glass transition is the transition between the high elastic state and the glass state. From a molecular structure perspective, the glass transition temperature is a relaxation phenomenon of the amorphous part of a polymer from a frozen state to a thawed state.

Taking DSC as an example, as the temperature gradually increases and passes through the glass transition temperature of the polymer, the baseline on the DSC curve shifts towards the endothermic direction (see figure). The point A in the figure is the starting point of deviation from the baseline. Extend the baseline before and after the transformation, and the vertical distance between the two lines is the step difference Δ J. At Δ J/2, point C can be found. Take a tangent from point C and intersect with the previous baseline at point B. The temperature value corresponding to point B is the glass transition temperature Tg.

Common crystalline plastics include polyethylene PE, polypropylene PP, polyoxymethylene POM, polyamide PA6, polyamide PA66, PET, PBT, etc

Amorphous plastics include: polycarbonate ABS、 Transparent benzene, vinyl chloride, etc. (such as plastic watch cases, TV cases, etc.)

What is the oxidation induction period?

The oxidation induction period (OIT) is a measure of the time it takes for a sample to undergo an automatic catalytic oxidation reaction under high temperature (200 degrees Celsius) oxygen conditions. It is an indicator for evaluating the material's ability to resist thermal degradation during molding, storage, welding, and use. The oxidation induction period (OIT) method is a method that uses differential thermal analysis (DTA) to test the degree of accelerated aging of plastics in high-temperature oxygen based on the exothermic reaction of plastic molecular chain breakage. The principle is to place the plastic sample and an inert reference material (such as alumina) in a differential thermal analyzer, and rapidly replace the inert gas (such as nitrogen) in the sample chamber with oxygen at a certain temperature. Test the changes in DTA curve (differential thermal spectrum) caused by sample oxidation and obtain the oxidation induction period (time) OIT (min) to evaluate the thermal aging resistance of plastics.