Production of Polyethylene [PDF]

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Production of Polyethylene There are two forms of polyethylene that can be produced via different production processes - high and low density.



High density polyethylene (HDPE)



Form



Low density polyethylene (LDPE)



Name of process



Ziegler-Natta process High pressure (1000 to 3000 Pressure of a few atmospheres, atmospheres), high temperature temperatures of about 60°C, and a (300°C), and an initiator (usually an catalyst organic peroxide) The peroxide initiator splits to form free radicals, which allow the initiation of the joining of ethylene The polymerisation occurs on the monomers (the initiator is not a surface of the catalyst catalyst as it gets incorporated into the polymer) Significant chain branching, meaning Unbranched polyethylene molecules that polymer chains cannot pack that are able to pack closely together closely together or in an orderly way in an orderly fashion



Requirements



Polymerisation process



Branching of polymer formed



Molecular weight Up to 1 000 000 g/mol of molecules formed



Up to 3 000 000 g/mol



Recycling symbol



The production processes for polyethylene



Structure of polyethylene