Polyester resin, as a widely used polymer material, its properties and quality are very important. The melting point is a key index to evaluate the purity and composition of polyester resin, and the determination method and accuracy have naturally become an important research content. In this paper, we will deeply discuss the determination method, principle and practical application significance of polyester resin melting point.

The importance of melting point determination
The melting point refers to the temperature at which a substance changes from a solid state to a liquid state, which not only reflects the purity of the substance, but also provides a reference for the composition of the polymer. For polyester resin, melting point is an important index to evaluate its performance and quality. An accurate melting point determination can help researchers understand the structure and purity of the resin and provide a basis for further application and research.

Measurement principle
When we observe the state changes of a polyester resin sample at different temperatures, we can infer its corresponding melting point and melting range from these changes. By observing the phase change of microsamples under a microscope, we can know the corresponding melting point and melting range.

Determination method and equipment
To determine the melting point, it is first necessary to prepare the corresponding equipment and materials. This includes:

Scales accurate to 0.001g for weighing samples.

Beaker and mortar for sample handling and grinding.

This is a specialized device consisting of a binocular variable magnification stereo microscope, a heating plate with its adjustable temperature regulator, a temperature measuring display, and a sample heating and insulation platform.

Method and significance of determination of melting point of polyester resin

The specific determination process consists of taking a small sample (less than 0.1mg), grinding it and spreading it evenly on a glass sheet, then covering it with another glass sheet and placing it in the appropriate position on a heated and insulated platform. Subsequently, the sample is viewed using a microscope while heating and displaying the test temperature. When the temperature is close to the expected melting point, the heating rate is adjusted until the sample is observed to change from a solid state to a liquid state or a glassy state to a highly elastic state, at which point the temperature is the melting point.

Result representation and reference standard
The result of the melting point determination shall be the arithmetic average of the three measurements and be accurate to one decimal place. In addition, in order to ensure the accuracy and consistency of the determination, we should refer to the relevant standards, such as CNS 1508-82 “Determination of the melting point of Chemical reagents”.

Method and significance of determination of melting point of polyester resin

Sum up
The determination of the melting point of polyester resin is not only a key step to evaluate its purity and properties, but also has important significance for further research and application. Accurate melting point determination can provide researchers with valuable information to help them better understand and optimize the properties and applications of polyester resins. With the progress of science and technology, we have reason to expect the emergence of more advanced and accurate determination methods and equipment to further promote the development of polyester resin research and application.