Polyethylene is the most common plastic. Its global production is ca. 80 million tones.
Chemical Formula: (C2H4)nH2 http://apps.kemi.se/flodessok/floden/kemamne_eng/polyeten_eng.htm
Published on: Mar 4, 2016
Transcripts - Polyethene
1.1 Chemical structure
2.1 physical properties
2.2 chemical properties
5. Groups of polyethylene
The most common plastic
global production is ca. 80 million tones
chemical formula: (C2H4)nH2
» Very simple structure, the simplest of all
» carbon atoms + two hydrogen atoms.
» thermoplastic polymer
» consists of long hydrocarbon chains
» white waxy
» the melting point is typically in the range 120 to 180 °C
» May or may not be observable
- molecular weight
- melting point
» excellent chemical resistance
not attacked by strong acids or strong bases
» resistant to gentle oxidants and reducing agents
» burns slowly with a blue flame having a yellow tip
giving off an odour of paraffin
» can be dissolved in hydrocarbons
» insoluble in water and most organic solvents
» does not conduct electricity
» can be dissolved at elevated temperatures
» ingredient of monomer is ethylene.
gaseous hydrocarbon with the formula C2H4
» ethylene must be of high purity
» Ethylene is generated by dehydration of
» highly exothermic.
» metal chlorides or metal oxides are used.
» common catalysts consist of titanium(III)
» cracking/decomposing petroleum
small, reactive ethane molecules
can be rearranged
» Ethene molecules polymerize to long chains of
chains close to each other by weak bonds
forming a material, comparable with the fibers of a
» children's toys
» bullet proof vests
- Plastic bag, e.g. grocery bags
- Plastic films
- Bottles, e.g. shampoo bottles
- Geomembranes: (HDPE) and (LDPE)
» two types of polyethylene:
1. HDPE: high density poly ethene ---> low
2. LDPE: low density poly ethene --> high
» LDPE : soft thus suitable for manufacture of
packaging, films soft tubes and hoses
» HDPE: for piping
1. Polyethylene film most lightweight and durable packaging
2. Plastic packaging contributes to reducing food spoilage rates.
3. Polyethylene ducting is compatible with most fans, heaters,
air conditioners, air handling units, etc
4. Polyethylene Bags use less energy and resources to create
than glass or paper.
5. Clear polyethylene allows recipients to view the contents
(such as a magazine cover)
1. Polyethylene is not biodegradable, it accumulates if
dumped in the soil
2. Polyethylene threatens the life in the water bodies.
3. Polyethylene is likely to clog the drains problems in
the water flow of the pipes
4. Polyethylene is harmful for animals if swallowed.
5. If polyethylene is burnt in open air Hydrogen cyanide