Polymers

Definition
Polymers are long chains of molecules made from combination of many small molecules called monomers. Polymerisation is a process of combining monomers to form a long chain of molecules.

source: http://hsc.csu.edu.au/senior_science/options/polymers/2973/SS951.html

Naturally Occurring Polymers

Are polymers that occur naturally, like...:

1. Rubber
2. Cellulose
3. Starch
4. Protein
5. Fat
6. Nucleic acid

Synthetic Polymer

Synthetic polymers are often referred to as "plastics", such as the well-known polyethylene and nylon.

Uses of some General Synthetic Polymers with their Names and Monomer Units are as Follows:-

Name(s)	Formula	Monomer	Uses
Polyethylene low density (LDPE)	–(CH2-CH2)n–	ethylene CH2=CH2	Used in film wrap, plastic bags
Polyethylene high density (HDPE)	–(CH2-CH2)n–	ethylene CH2=CH2	Used in electrical insulation bottles, toys
Poly(vinyl chloride) (PVC)	–(CH2-CHCl)n–	vinyl chloride CH2=CHCl	Used in pipes, siding, flooring.etc.
Poly(vinylidene chloride) (Saran A)	–(CH2-CCl2)n–	vinylidene chloride CH2=CCl2	Used in seat covers, films etc.
Polystyrene (PS)	–[CH2-CH(C6H5)]n–	styrene CH2=CHC6H5	Used in toys, cabinets packaging etc.
Polyacrylonitrile (PAN, Orlon, Acrilan)	–(CH2-CHCN)n–	acrylonitrile CH2=CHCN	Used in rugs, blankets clothing etc.
Polytetrafluoroethylene (PTFE, Teflon)	–(CF2-CF2)n–	tetrafluoroethylene CF2=CF2	Used in non-stick surfaces, electrical insulation
Poly(vinyl acetate) (PVAc)	–(CH2-CHOCOCH3)n–	vinyl acetate CH2=CHOCOCH3	Used in latex paints, adhesives etc.
cis-Polyisoprene natural rubber	–[CH2-CH=C(CH3)-CH2]n–	isoprene CH2=CH-C(CH3)=CH2	Requires vulcanization for practical use and vulcanized rubber is used in tyres etc.
Polychloroprene (cis + trans) (Neoprene)	–[CH2-CH=CCl-CH2]n–	chloroprene CH2=CH-CCl=CH2	It is a synthetic rubber and is oil resistant so used in mats etc.

source: http://www.tutorvista.com/chemistry/synthetic-polymers-and-their-uses

Properties of Synthetic Polymers

Synthetic polymers are not biodegradable (not decomposed by microorganism). The careless disposal of items made from synthetic polymers such as plastic causes environmental pollution. The effects of burning and careless disposal of items made from synthetic polymers on the environments are as follow;

    (a) Burning of synthetic polymers

        ∆ Releases pollutants that endanger health such as smoke, gasses that are smelly, poisonous and corrosive such                          a          as sulphur dioxide, pollutants that cause acid rain and the green house effect.

    (b) Careless disposal of synthetic polymers

        ∆ Spoils the beauty of the environment.

        ∆ Causes flash floods during heavy rainfall.

        ∆ Endangers marine lifelike turtles that accidentally eat polymers such as plastics as food

The best way to manage used items made from synthetic polymers is to recycle them. Plastics that are biodegradable can be used instead to reduce environmental pollution.


References


-Longman Essential Chemistry Spm