polythene

MARY BLK:C

= = =//__POLYTHENE__//=

General Introduction
 * Polyethylene** or **polythene** ([|IUPAC] name **polyethene** or **poly(methylene)**) is the most widely used [|plastic], with an annual production of approximately 80 million metric tons.[|[1]] Its primary use is within packaging (notably the [|plastic shopping bag]).

The Structure Of Polythene



Polyethylene contains the [|chemical elements] [|carbon] and [|hydrogen].
===Polyethylene is created through [|polymerization] of ethene. It can be produced through [|radical polymerization], [|anionic addition polymerization], [|ion coordination polymerization] or [|cationic addition polymerization]. This is because ethene does not have any substituent groups that influence the stability of the propagation head of the polymer. Each of these methods results in a different type of polyethylene.===

Classification
===Polyethylene is classified into several different categories based mostly on its [|density] and [|branching]. The mechanical properties of PE depend significantly on variables such as the extent and type of [|branching], the crystal structure and the [|molecular weight]. With regard to sold volumes, the most important polyethylene grades are HDPE, LLDPE and LDPE.===
 * [|Ultra high molecular weight polyethylene] (UHMWPE)
 * [|Ultra low molecular weight polyethylene] (ULMWPE or PE-WAX)
 * [|High molecular weight polyethylene] (HMWPE)
 * [|High density polyethylene] (HDPE)
 * [|High density cross-linked polyethylene] (HDXLPE)
 * [|Cross-linked polyethylene] (PEX or XLPE)
 * [|Medium density polyethylene] (MDPE)
 * [|Linear low density polyethylene] (LLDPE)
 * [|Low density polyethylene] (LDPE)
 * [|Very low density polyethylene] (VLDPE)

How To Produce Polythene
It can be produced through radical polymerization, anionic addition polymerization, ion coordination polymerization or cationic addition polymerization. This is because ethene does not have any substituent groups which influence the stability of the propagation head of the polymer. Each of these methods results in a different type of polyethylene. History ===Polyethylene was first synthesized by the [|German] chemist [|Hans von Pechmann] who prepared it by accident in 1898 while heating [|diazomethane]. When his colleagues [|Eugen Bamberger] and [|Friedrich Tschirner] characterized the white, waxy, substance that he had created they recognized that it contained long -CH2- chains and termed it //polymethylene//.===

Polythene Affects Us
===Sources Of Pictures=== [] []
 * Polyethylene is probably the polymer you see most in daily life. Polyethylene is the most popular** [|**plastic**] **in the world.** Polyethylene is cheap, flexible, durable, and chemically resistant.**This is the polymer that makes grocery bags, shampoo bottles, children's toys, and even bullet proof vests. For such a versatile material, it has a very simple structure, the simplest of all commercial polymers. A molecule of polyethylene is nothing more than a long chain of carbon atoms, with two hydrogen atoms attached to each carbon atom.**

Sources Of Information
[] [] [|www.packagingtoday.com/introplasticexplosion.hhttp://www.wisegeek.com/what-is-polyethylene.htm] []
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