Abbreviation: HDPE See more. Polyethylene is made from the polymerization of ethylene (or ethene) monomer. Ethylene consists of covalently bound carbons and pendant hydrogens. in several markets (packaging, automotive, electrical, etc.). History: High-density polyethylene (HDPE) was introduced as a bearing surface in orthopedics in 1962 by Sir John Charnley from Manchester, England. You may be wondering what the n represents in the first image. The difference between polyolefin and polyethylene is that polyolefin is made from the polymerization of alkenes whereas polyethylene is made from the polymerization of ethylene molecules. High-density polyethylene definition, polyethylene consisting mainly of linear, or unbranched, chains with high crystallinity and melting point, and density of 0.96 or more, produced at low pressure and used chiefly for containers and articles made by injection molding. 1-butene, 1-hexene, and 1-octene). In chemistry, n acts as a placeholder for a number.N gives you some idea about the potential length of the chain. polyethylene [pol″e-eth´ĭ-lēn] polymerized ethylene, (—CH2—CH2—)n, a synthetic plastic material, forms of which have been used in reparative surgery. Polyethylene is a good example for polyolefin. HDPE is a type of polyethylene, the most common plastic which accounts for over 34% of the global plastic market. Cross-linked polyethylene, commonly abbreviated PEX, XPE or XLPE, is a form of polyethylene with cross-links.It is used predominantly in building services pipework systems, hydronic radiant heating and cooling systems, domestic water piping, and insulation for high tension (high voltage) electrical cables. Definition: A linear polymer of the simple ethylene molecule synthesized as a fine white powder. Polyethylene definition is - a polymer of ethylene; especially : any of various partially crystalline lightweight thermoplastics (CH2CH2)x that are resistant to chemicals and moisture, have good insulating properties, and are used especially in packaging and insulation. Polyethylene (PE) is an organic polymer made by the polymerization of monomer subunits. LLDPE (Linear-Low Density Polyethylene) is defined by a density range of 0.915 - 0.925 g/cm 3. is a substantially linear polymer, with significant numbers of short branches, commonly made by copolymerization of ethylene with short-chain alpha-olefins (e.g. Summary – Polyolefin vs Polyethylene. The chemical formula of polyethylene is (C 2 H 4) n. Polyethylene is a combination of similar polymers of ethylene with different values of n. A typical polyethylene molecule can contain more than 500 ethylene subunits. Polyethylene is used in applications ranging for films, tubes, plastic parts, laminates, etc. Methane gas (Figure 1-1a) is Polyolefin are polymer materials made from small alkene monomers. Manufacture: Definition of Polyethylene Terephthalate “A polyethylene terephthalate is a condensation polymer of both terephthalic acid and ethylene glycol.” The reaction’s by-product to create this compound is water, and so it is an example of step-growth polymerization or condensation. Based on this mechanism, there are two types of polymerization. Physical Chemistry and Mechanical Properties of HDPE High-density polyethylene (HDPE)(0.941