Plastic Fantastic For some time now, plastics have been used commercially as alternatives to natural materials such as wood, metals, ceramics and glass. Why are they used extensively? www.dkimages.com relatively cheap www.clubi.ie lightweight picasaweb.google.com strong easy to process Most polymers are good electrical insulators and also good thermal insulators www.global-b2b-network.com These properties are highlighted in science education and by their extensive use in the home.

Lately there has been increasing interest in developing new plastic materials with entirely new properties for all sorts of new uses. news.bbc.co.uk www.tomshardware.com Over the last 30 years there has been increasing interest in a number of plastics found to be electrical conductors. www.tf.uni-kiel.de wallpaperweekly.com Researchers have discovered that conjugated polymers, which have a pathway of alternating double and single bonds, exhibit metallic and semiconductor characteristics. These polymers possess a delocalised pi-electron system along their backbone that confers semiconducting properties to the polymer. Poly(ethyne) is included within Unit 2 Higher Grade Chemistry : The world of Carbon, section e) Polymers as an example of a conducting polymer.

In the future, conducting plastics will be used because the material and manufacturing costs are low thin films can be used to cover large areas are flexible. Conducting polymers will not be a general replacement for metals but will be used where these advantages can be exploited for medium conductivity applications.

Poly(pyrrole) – A Conducting Plastic Poly(pyrrole) and poly(aniline) are commonly used conducting polymers in industry because they are relatively stable. Polypyrrole is not directly processable and is deposited in film form by electrochemical means. Current commercial applications of these plastics include battery electrodes, conductive coatings for electrostatic speakers, capacitor electrolytes, transparent conductive coatings, and electrostatic discharge coatings. www.ttiinc.com

Aims for the day Prepare a sample of a polymer and test its conductive properties If time permits: Work collaboratively with others to critically analyse some pros and cons of plastics and develop an informed argument as to its worth to society