High activity catalyst used for synthesizing ultrahigh molecular weight polyethylene and preparation method

Abstract

The invention discloses a high activity catalyst used for synthesizing ultrahigh molecular weight polyethylene and a preparation method, the catalyst is prepared by reacting a magnesium halide carrier, a titanium compound, at least one organic alcohol and at least one halogen substituted aluminum alkyl compound; the method comprises the following steps: 1) under certain temperature, magnesium halide and alcohol are reacted; 2) after completely dissolving, the product obtained in the step 1) is reacted with chlorinated alkyl aluminum and a titanium compound in order; 3) a supersonic wave apparatus is used for treating the product in the step 2); and 4) removing a solvent in the product obtained in the step 3) to obtain the high activity catalyst. The high activity catalyst and a cocatalyst should be used together for polymerization, and can be used for synthesizing ultrahigh molecular weight polyethylene resin. According to the invention, an ultrasonic treatment technology is used, so that final catalyst particle form is controlled, the polymerization efficiency of the catalyst can be effectively improved, the stabilization of polymerization dynamics can be guaranteed, and the molecular weight of the polymerization product is high.

Description

technical field [0001] The invention relates to a highly active catalyst for synthesizing ultra-high molecular weight polyethylene and a preparation method thereof, in particular to a highly active catalyst for synthesizing ultra-high molecular weight polyethylene by ultrasonic treatment and a preparation method thereof. Background technique [0002] Ultra-high molecular weight polyethylene (UHMWPE for short) usually refers to the viscosity-average molecular weight of 1.5×10 6 The above linear structure polyethylene has excellent stress crack resistance, electrical insulation, wear resistance, etc. due to the molecular weight of UHMWPE as high as one million or even several million. It is especially suitable for the production of components that require high physical properties, such as transmission gears, artificial joints, etc. Compared with ordinary high molecular weight polyolefins, UHMWPE has excellent acoustic resistance, radiation resistance, heat resistance, moistur...

AI Technical Summary

Problems solved by technology

However, in the preparation process of the catalyst, the carrier magnesium chloride has irregular flaky particles produced during the original grinding and pulverization in the slurry reaction system, resulting in poor morphology and uneven thickness of the obtained solid catalyst particles, so that the polymer has poor morphology and fine particles. More powder

[0005] A series of Ziegler-Natta type catalysts are disclosed in CN1099041A, CN1229092, and CN85100997. The shortcoming of this traditional method is that the catalyst particles are completely controlled by the precipitation process, and its particle size and particle size distribution are difficult to control. It is difficult to use and recycle, and the polymerization activity is also difficult to control

[0011] Moreover, in the existing patents for the preparation of UHMPWE catalysts, it has not been found that during the loading process of the active center, the particle size of the catalyst is made uniform through the action of ultrasonic waves, the specific surface area of ​​the catalyst reaction is increased, and finally the molecular weight of the resin and the polymerization efficiency of the UHMWPE catalyst are simultaneously increased.

Images