Method for improving metallocene polyethylene cross-linking efficiency and optimizing net structure of conjugate

Abstract

The present invention discloses a method for raise the cross-linking efficiency of metallocene PE and optimizing the network structure of the cross-linked product, and the method comprising, in the process of organic peroxide cross-linking metallocene PE, adding the following components: 98.9 percent-99.1 percent by mass of metallocene PE, 0.3 percent by mass of initiator, 0.1 percent-0.3 percentby mass of nucleater and 0.5 percent by mass of carbon white, adding the metallocene PE, initiator, nucleater and carbon white into a low-speed mixer to premix, adding the materials in the premixing step into the twin screw extruder to do cross-linking reaction, extruding the material to obtain cross-linked metallocene PE product comprising 60-75 percent by mass of gel. The invention is capable ofraising the efficiency of initiation of the initiator, and the method make the cross-linked metallocene PE to have a more gel content, make the cross-linking network more uniformly, and at the same times, make sure mechanical properties of the cross-linked metallocene PE be excellent.

Description

technical field [0001] The invention relates to a method for improving the crosslinking efficiency of metallocene polyethylene, in particular to a method for improving the crosslinking efficiency of metallocene polyethylene and optimizing the network structure of the crosslinked product. Background technique [0002] Metallocene polyethylene is a new type of polyethylene resin, which has been widely used in film and other fields. However, according to its structural characteristics, it has always been the focus of attention to expand its application range and improve its use value through modification. [0003] There are two methods of polymer modification: chemical modification and physical modification. Practice has proved that chemical modification is a more effective way to obtain new materials. The chemical modification of metallocene polyethylene mainly focuses on chemical crosslinking. [0004] For polyethylene, the more commonly used cross-linking methods include ...

AI Technical Summary

Problems solved by technology

CN1760251A discloses a cross-linkable peroxide low-density polyethylene plastic and its preparation method. The invention dissolves a high-melting antioxidant through a cross-linking agent and uniformly disperses it in the peroxide-crosslinkable low-density polyethylene In the insulating material, it solves the defect that the peroxide crosslinkable insulating material has unmelted antioxidant in the kneaded finished product in the past, and the plastic made of the inventive formula is suitable for insulating layers with different rated voltages below 35kV The ratio of the initiator used is 1.6-2.5 parts / 100 parts of polyethylene, and the ratio of the other component antioxidant is 0.001-0.005 parts / 100 parts of polyethylene, which is difficult to achieve long-term anti-aging effect and will also Prior to the action of polyethylene and the initiator, it affects the initiation efficiency of the initiator

CN1735649A adopts the impregnation method to infiltrate a certain proportion of organic peroxides into polyethylene particles prepared by different catalytic systems. It is considered to use this raw material for cross-linking to produce PEXA pipes. It focuses on the selection of catalytic systems and the size of polyethylene particles. selection, compared the degree of cross-linking of the cross-linked products without referring to the amount of initiator and the initiation efficiency

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