What are the disadvantages and advantages of PBT raw materials

Polybutylene terephthalate (PBT) is a material widely used in the field of engineering plastics, favored for its excellent physical properties and versatility. PBT's high strength and hardness make it perform well when subjected to mechanical stress, and its tensile strength usually exceeds 60MPa, making it suitable for applications with large loads. In addition, PBT's wear resistance and low friction coefficient make it an ideal choice for fields such as mechanical transmission parts and bearings, and can effectively resist friction and wear.

In terms of electrical insulation, PBT exhibits extremely low conductivity and dielectric constant, so it is widely used in the manufacture of electronic and electrical components. Its high breakdown voltage ensures stable performance under high voltage environments, making it suitable for use in various electrical equipment, and can effectively prevent short circuits and electrical failures.

In addition, PBT has excellent chemical stability and can resist corrosion from a variety of chemicals and solvents. Its acid, alkali and oil resistance make it widely used in industries such as automobiles, chemicals and food processing. The material's resistance to hot water also allows it to maintain stable performance under high temperature conditions, making it suitable for use in harsh environments.

The thermal stability of PBT is also worth paying attention to. Its melting point is about 220℃. It can maintain good mechanical properties at high temperatures and work at 140℃ for a long time without thermal decomposition or deformation. In addition, PBT has good processability, low melt viscosity and excellent fluidity, and is suitable for making parts with complex shapes through various molding processes such as injection molding and extrusion. Pre-drying is required before molding, but after the moisture content drops to 0.02%, it can be processed smoothly to avoid the generation of shrinkage holes and bubbles.

In terms of dimensional stability, PBT can maintain good stability under different temperature and humidity conditions, which is suitable for the manufacture of high-precision parts. Its modifiable characteristics also provide greater flexibility for its application. By adding glass fiber, inorganic fillers and flame retardants, its mechanical properties, heat resistance and flame retardancy can be significantly improved.

However, the application of PBT also faces some challenges. Its flammability may release toxic substances under high temperature conditions. Therefore, in certain specific fields, such as the electronics and electrical industry, flame retardant measures need to be taken to ensure safety. In addition, PBT is prone to hydrolysis in high temperature environments, resulting in increased volume resistance and dielectric loss, which limits its long-term application in humid environments.

PBT has a relatively low notch impact strength and is prone to breakage when impacted. Therefore, in situations where it needs to withstand impact loads, it may be necessary to enhance its impact toughness through modification measures. At the same time, PBT has a large molding shrinkage rate, which may cause warping and deformation during the molding process. Adding modifiers such as glass fiber can reduce this problem to a certain extent and improve dimensional stability.