PET structure

- Jun 18, 2019-

PET structure

The PET plastic molecular structure is highly symmetrical and has a certain crystal orientation ability, so it has high film formation and formation. PET plastics have good optical properties and weather resistance, and amorphous PET plastics have good optical transparency. In addition, PET plastics have excellent wear resistance, dimensional stability and electrical insulation. PET bottles have been widely used because of their high strength, good transparency, non-toxicity, penetration resistance, light weight and high production efficiency. PBT and PET molecular chain structure is similar, most of the properties are the same, but the molecular backbone is changed from two methylene groups to four, so the molecules are more supple and the processing performance is better.

PET is a milky white or light yellow highly crystalline polymer with a smooth and shiny surface. It is resistant to creep, fatigue and friction, has low abrasion and high hardness, and has the highest toughness in thermoplastics. It has good electrical insulation properties and is less affected by temperature, but has poor corona resistance. Non-toxic, weather-resistant, chemical-resistant, and hygroscopic, and drying before molding is a must. It is resistant to weak acids and organic solvents, but it is not soaked in heat-resistant water and is not resistant to alkali.

The PET resin has a high glass transition temperature, a slow crystallization rate, a long molding cycle, a long molding cycle, a large molding shrinkage ratio, a poor dimensional stability, a brittleness in crystallization, and low heat resistance.

Through the improvement of nucleating agent and crystallization agent and glass fiber reinforcement, in addition to the properties of PBT, PET has the following characteristics:

1. The heat distortion temperature and long-term use temperature are the highest among thermoplastic general engineering plastics;

2. Because of the high heat resistance, the reinforced PET is immersed in a solder bath of 250 ° C for 10 s, and it is hardly deformed or discolored, and is particularly suitable for preparing electronic and electrical parts for soldering;

3. The bending strength is 200MPa, the elastic modulus is up to 4000MPa, the creep resistance and fatigue resistance are also good, the surface hardness is high, and the mechanical properties are similar to those of thermosetting plastics;

4. Since the ethylene glycol used in the production of PET is almost half the price of the butanediol used in the production of PBT, PET resin and reinforced PET are the lowest in engineering plastics and have a high cost performance.

5. PET resin bonding: sili-1706 one-component room temperature vulcanizate, after curing, the elastomer has excellent waterproof, anti-vibration adhesive, high and low temperature resistance, because 泀力科技 is based on the molecular structure of the resin, so special Used to bond engineering plastics.

6. PET alloy properties: Since the ethylene glycol used in the production of PET is almost half the price of the butanediol used in the production of PBT, PET resin and reinforced PET are the lowest in engineering plastics and have a high cost performance. To improve PET performance, PET can be alloyed with PC, elastomer, PBT, PS, ABS, PA.