Polyethylene copper wire is a cable with polyethylene as the outer sheath. Polyethylene is a thermoplastic resin obtained by polymerization of ethylene.

Introduction

Referred to as PE, it is a thermoplastic resin obtained by polymerization of ethylene. In industry, it also includes copolymers of ethylene and a small amount of ¦Á-olefins.

Polyethylene is odorless, non-toxic, feels like wax, has excellent low temperature resistance (the lowest operating temperature can reach -70¡«-100¡æ), good chemical stability, can withstand the corrosion of most acids and alkalis (not resistant to oxidizing acids), is insoluble in general solvents at room temperature, has low water absorption, and has excellent electrical insulation properties; but polyethylene is very sensitive to environmental stress (chemical and mechanical effects) and has poor heat aging resistance. The properties of polyethylene vary from variety to variety, mainly depending on the molecular structure and density. Different production methods can produce products of different densities (0.91¡«0.96g/cm3). Polyethylene can be processed by the molding method of general thermoplastics (see plastic processing). It has a wide range of uses, mainly used to make films, containers, pipes, monofilaments, wires and cables, daily necessities, etc., and can be used as high-frequency insulation materials for televisions, radars, etc. With the development of petrochemicals, polyethylene production has developed rapidly, and its output accounts for about 1/4 of the total plastic output. In 1983, the world's total polyethylene production capacity was 24.65Mt, and the capacity of the equipment under construction was 3.16Mt.

Types of polyethylene

(1) LDPE: low-density polyethylene, high-pressure polyethylene

(2) LLDPE: linear low-density polyethylene

(3) MDPE: medium-density polyethylene, bimodal resin

(4) HDPE: high-density polyethylene, low-pressure polyethylene

(5) UHMWPE: ultra-high molecular weight polyethylene

(6) Modified polyethylene: CPE, cross-linked polyethylene (PEX)

(7) Ethylene copolymers: ethylene-propylene copolymer (plastic), EVA, ethylene-butene copolymer, ethylene-other olefin (such as octene POE, cyclic olefin) copolymer, ethylene-unsaturated ester copolymer (EAA, EMAA, EEA, EMA, EMMA, EMAH)

Linear polyethylene with a molecular weight of 3,000,000-6,000,000 is called ultra-high molecular weight polyethylene (UHMWPE). Ultra-high molecular weight polyethylene has very high strength and can be used to make bulletproof vests.

Main methods

Liquid phase method (divided into solution method and slurry method) and gas phase method (phase type of material in the reactor). China mainly uses the slurry method with Ziegler catalyst.

Description of conditions and process: Ethylene with a purity of more than 99% is polymerized in gasoline at a pressure of 0.1-0.5MPa and a temperature of 65-75¡æ in the presence of catalysts titanium tetrachloride and diethylaluminum monochloride to obtain HDPE slurry. The residual catalyst is destroyed by alcoholysis, neutralized, washed with water, and gasoline and unpolymerized ethylene are recovered. The product is obtained by drying and granulation.

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