Composition for preparing ultrahigh molecular weight polyethylene pipe material

Abstract

The invention relates to a composition for preparing an ultrahigh molecular weight polyethylene pipe material. The composition is prepared from the following raw materials: ultrahigh molecular weight polyethylene, a fluorine-containing polymer processing aid, polyethylene wax, a calcium stearate / zinc stearate compound, a compound antioxidant and carbon black according to the corresponding mass ratio of 100:0.01-0.05:2-6:0.1-1.0:0.2-0.4:1-3; wherein the viscosity average molecular weight of the ultrahigh molecular weight polyethylene is 200*10<4>-300*10<4>; the fluorine-containing polymer processing aid is a fluorinated copolymer of vinylidene fluoride; the mass ratio of the calcium stearate to zinc stearate is 1-3:1; the compound antioxidant is a mixture of (A) a hindered phenol antioxidant and (B) a phosphite ester antioxidant according to the mass ratio of A:B = 1:1-3. According to the formula, the ultrahigh molecular weight polyethylene pipe composition has excellent thermal oxidative aging resistance, is higher than 4530 min in oxidizing induction time at 200 DEG C, and has excellent mechanical performance, wear-resisting property, corrosion resistance, thermal oxidative aging resistance and extrusive processability.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a composition for preparing ultra-high molecular weight polyethylene pipes. Background technique [0002] Ultra-high molecular weight Polyethylene (UHMWPE) generally refers to polyethylene (PE) with a relative molecular mass of more than 1.5 million, while the relative molecular mass of ordinary PE is generally only 20,000 to 300,000. Domestic UHMWPE The relative molecular mass can reach 4 million to 5 million, while the relative molecular mass of UHMWPE produced in Germany is as high as 10 million. [0003] The extremely high relative molecular weight of UHMWPE endows it with extremely excellent properties: [0004] ①Excellent resistance to environmental stress cracking, which is 200 times that of ordinary high-density polyethylene (HDPE) and 5-10 times that of ordinary plastics; ②Extremely strong wear resistance, ranking first in plastics, is 5-7 times th...

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Problems solved by technology

[0012] Chinese patents CN101134827 and CN1807062 use liquid crystal polymers to modify UHMWPE. Liquid crystal polymers have excellent mechanical properties, wear resistance and fluidity. Combining liquid crystal polymers with UHMWPE can significantly improve the processing performance of UHMWPE, and Its mechanical properties and wear resistance are improved, but the disadvantage is that the processing temperature is as high as 250-300 ° C, the energy consumption is high, and the heat and oxygen aging resistance is not mentioned in the patent. For UHMWPE pipes, the heat and oxygen aging resistance Performance is also a very important indicator, which affects the service life of the pipe

[0013] Chinese patent CN1428370 Mix 85-95% ultra-high molecular weight polyethylene, 3-15% polysiloxane, 0.2-2% antioxidant, stir evenly, and dry in a vacuum oven at 40-60°C for 5-7 hours , the dried raw materials are extruded and granulated. The fluidity of this blend is greatly improved due to the addition of silicone as a modifier. The prepared UHMWPE pipe has excellent wear resistance and corrosion resistance. and low temperature resistance, but the patent granulates the special material, the cost is high, and the heat and oxygen aging resistance is not mentioned in the patent

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