Preparation process of high-density polyethylene

High density polyethylene is an important synthetic resin material widely used in plastic products, pipelines, cables and other fields. The main method for preparing high-density polyethylene is catalytic polymerization, with specific steps as follows:
1. Catalyst preparation: Select an appropriate catalyst, such as titanium chloride/tributylaluminum, potassium chromate, etc., and load the catalyst on a carrier through fixed bed, fluidized bed, and other methods.
2. Aggregation reaction: Contact ethylene gas with a catalyst at high pressure (100-300 MPa) to obtain polyethylene. The reaction temperature is generally between 70-100 ℃, and the reaction time ranges from a few minutes to several hours.
3. Separation and purification: The reaction mixture is separated into high-density polyethylene through distillation, crystallization, and other methods.
It should be noted that during the preparation of high-density polyethylene, attention should be paid to the effects of oxygen, moisture, and other factors on the catalyst, as well as the control of parameters such as polyethylene molecular weight and molecular weight distribution. In addition, new reactor materials and processes such as fluidized bed and gas-phase polymerization can be used in industry to improve preparation efficiency and product quality.
-1-