| Sign In | Join Free | My benadorassociates.com |
|
| Sign In | Join Free | My benadorassociates.com |
|
Thermal performance test
Basic introduction
The properties and changes of materials are studied by measuring
the changes in physical properties during the heating or cooling
process of materials, or the fractal identification of materials.
Physical properties include mass, temperature, enthalpy, size,
mechanical, acoustic, electrical and magnetic properties of
materials.
Analysis purpose and significance
Thermal analysis of materials can quickly and accurately measure
changes in crystal transformation, melting, sublimation,
adsorption, dehydration, decomposition, etc. of materials, and has
a wide range of applications in characterizing the thermal
properties, physical properties, mechanical properties and
stability of materials.
It has very important practical significance for the research on
the physical and chemical properties of inorganic, organic and
polymer materials and the quality control in the production of
related materials.
Test items
1. Glass transition temperature
The temperature at which the plastic drops from the melting
flowable temperature to the solid state is called the glass
transition temperature. At this time, the molecular chain segments
can basically not move, and it is also difficult to rotate and
buckle the internal chain links. There is only a little movement
and stretching between atoms and ordinary elastic deformation, so
the plastic at this time will be very brittle.
2. Decomposition temperature
Decomposition temperature refers to the temperature at which the
macromolecular chain of plastic breaks when heated, and is also one
of the indicators for identifying the heat resistance of plastic;
when the melt temperature exceeds the decomposition temperature,
most of the melt will appear yellow, and the strength of the
product will be greatly reduced.
3. Modulus
Modulus is an important new energy parameter of engineering
materials. From a macroscopic perspective, modulus is a measure of
the size of an object's ability to resist deformation; from a
microscopic perspective, it is a reaction to the bond strength
between atoms, ions or molecules.
4.HDT (heat deformation temperature)
It shows whether the plastic material can maintain its shape under
high temperature and pressure. Generally, the short-term heat
resistance of plastic is expressed by heat deformation temperature.
5.CTE (linear expansion coefficient)
The linear expansion coefficient refers to the number of
centimeters of plastic elongation per centimeter when the
temperature rises by 1 degree Celsius. The linear expansion
coefficient of plastic is generally about ten times that of steel.
6. Pyrolysis temperature
Pyrolysis refers to the chemical process of converting a sample
(mainly polymer compounds) into several other substances (mainly
low molecular compounds) only through heat energy. Cracking can
also be called thermal cracking or pyrolysis. The sample cracking
temperature point is measured by instrumental analysis.
7. Crystallization temperature
The factors affecting polymer crystallization can be divided into
two parts: the regularity of the internal structure, and the
external concentration, solvent, temperature, etc. The more regular
the structure, the easier it is to crystallize, and vice versa, the
more difficult it is, becoming an amorphous polymer. Structural
factors are the most important.
8. Melting point
The melting point is the temperature at which a solid changes its
physical state from solid (melts) to liquid, which can generally be
expressed as Tm. The melting point is little affected by pressure.
The temperature at which the solid and liquid states of a pure
substance are in equilibrium under a certain pressure.
|
