Polyethylene Research Paper

Polyethylene is a polymer which is composed of a carbon double bond is converted to a unilateral Association to be more elastic , and is used in plastics production and film industry, as well as in our daily lives, such as pots and lids aluminum profiles also in shopping bags, glass cleaners and fuel tanks car, in addition to that used in engraving and weaving in synthetic fibers and adjusted to take qualities of flexibility, such as rubber. Polyethylene (abbreviated PE) or polyethene (IUPAC name polyethene or poly(methylene)) is the most common plastic. The annual global production is around 80 million tonnes. Its primary use is in packaging (plastic bags, plastic films, geomembranes, containers including bottles, etc.). Many kinds of polyethylene

>Physical, chemical properties

The high density polyethylene is a thermoplastic resin.
At room temperature the density is between 0,94 and 0,96 g/cm³, about 60 % is crystalline the remaining is amorphous.
Between 125° - 135° C, polyethylene melts and the viscosity is molecular weight dependent. The melt density drops to 0,80 g/cm³.
The polyethylene resists to the most chemical products and solvents. Only some substances, such as the decahydronaphtalene or some aromatic or halogenated hydrocarbons, dissolve the polyethylene at high temperatures.
The chemical destruction of polyethylene can occur only under the action of strong oxidizing agents such as fuming nitric acid or fuming sulphuric acid.

>Mechanical properties:

Polyethylene is of low strength, hardness and rigidity, but has a high ductility and impact strength as well as low friction. It shows strong creep under persistent force, which can be reduced by addition of short fibers. It feels waxy when touched.

>Thermal

Its mechanical properties depend significantly on variables such as the extent and type of branching, the crystal structure, and the molecular weight. There are several types of polyethylene:
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Chain branches:

The properties of polyethylene are highly dependent on kind and number of chain branches. The chain branches in turn depend on the process used: either the high-pressure process (only PE-LD) or the low-pressure process (all other PE grades). Low-density polyethylene is result by the high-pressure process by radical polymerization, thereby numerous short chain branches as well as long chain branches are formed. Short chain branches are formed by intramolecular chain transfer reactions, they are always butyl or ethyl chain branches because the reaction proceeds after the following mechanism
Mechanism for the emergence of side chains during synthesis of polyethylene (PE-LD).

usage in real live: