Modified ultra-high molecular weight polyethylene (UHMWPE) and application thereof on centrifugal pump

Abstract

The invention relates to a modified ultra-high molecular weight polyethylene (UHMWPE) that is characterized by being prepared by mixing 85 to 98 wt% of ultra-high molecular weight polyethylene with the molecular weight (measured by viscosimetry) of 1.5 to 5 millions and 2 to 15 wt% of potassium carbonate whisker processed by a coupling agent. The invention not only greatly improves the abrasion resistance of the UHMWPE, but also has the comprehensive effects of raising of use temperature, reduction of coefficient of thermal expansion and improvement of melting performance, processing and molding performance, production efficiency and product quality; and in particular, the invention is suitable for anti-corrosive and wear-resisting centrifugal pumps.

Description

technical field [0001] The invention relates to a modified ultra-high molecular weight polyethylene, especially the ultra-high molecular weight polyethylene modified with potassium carbonate whiskers to obtain ultra-high molecular weight polyethylene with good impact and wear resistance and processability, and has the advantages of corrosion resistance and corrosion resistance. Grinding applications on centrifugal pumps. Background technique [0002] Ultra-high molecular weight polyethylene (UHMWPE, molecular formula: -(-CH2-CH2-)-n) has excellent anti-corrosion performance, good wear resistance and economy, and one of its uses is as a corrosion-resistant and wear-resistant centrifugal Materials for pumps, e.g. as pump liners or extruded all-plastic pumps. UHMWPE has an extremely low melt index and poor processing fluidity. Therefore, it is used to form complex cavities such as centrifugal shell volutes. It cannot be formed by injection molding or extrusion molding. Ten th...

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Problems solved by technology

[0006] In the UHMWPE composition disclosed in Chinese patent CN1091758, 5 to 25% of inorganic fibers are added to UHMWPE with a molecular weight (measured by viscosity method) of more than 3 million, so that the heat distortion temperature of the modified material is increased by about 20°C, and the breaking strength of the material is improved. The coefficient of thermal expansion is reduced, but the wear resistance is basically not significantly improved; while adding inorganic fiber modification, the modification process is complicated, the production process increases, and the secondary heating of the modification can easily lead to the degradation of the material and the decrease of the molecular weight, which will also lead to a decrease in the performance of the material. decline

And although it is reported in the prior art that potassium carbonate whiskers have a modification effect on various polymer materials, they do not involve how to modify ultra-high molecular weight polyethylene, especially to meet its application in centrifugal pumps.

Therefore, the existing UHMWPE material centrifugal pumps have objectively long-term defects such as non-wear resistance and short service life when they are used at relatively high operating temperatures and transport media with high solid content, and have not been effectively resolved.

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