Polyethylene: Polyethylene are formed by polymerization of ethylene under high pressure and at moderately high temperature. The resulting polymers are then subjected to substitution and other reactions to yield the required plastic. Polyethylene's have good chemical resistance electrical resistance low water absorption and good flexibility. These are much cheaper than other plastics. However high temperature and sunlight affects the properties of polyethylene's adversely e.g. resistance to chemicals falls drastically at higher temperature.
USES:
(1) Used in manufacture of toys and other house hold articles.
(2) Used for the manufacturer of domestic pipes and gas pippins.
PROPERTIES:
(1) Due to strong inter: chain forces tensile strength is quite high.
(2) It can be vulcanized to a little extent to form cross linked structures with improved mechanical properties due to the little presence of double bonds. Thus this rubber cannot be hardened due to small number of cross linkages.
(3) It is highly resistant to atmosphere heat abrasion acids oils alkalis oxygen and ozone.
USES:
(1) Used as an insulation material in the electrical industry and in rubber based industries like inner tubes for the tyres of bicycles rickshaws and automobiles.
(2) Used as a solid fuel for rockets.