Introduction to Plastics and their Important Properties for Electronic Applications

The word plastic has its origins in the Greek language where ‘plastikos’ meant to form or shape. Today plastic has a number of meanings but the one which best fits the description of materials detailed in this work is that referring to any of various substances which harden and retain their shape after being moulded or formed by heat and pressure. This description is still rather broad, covering a large number of materials including many such as tar, clay and even mud which do not really agree with our current perception of a plastic. In order to qualify the word plastic, a more accurate description would be synthetic plastic, since this eliminates the naturally occurring materials that have plastic properties and only includes those derived by chemical means from relatively simple raw materials. Plastics are thus man-made polymers where the word polymer is an abbreviation of the two words poly and monomer and literally means many monomers. It should also be noted, however, that the word plastic is generally taken to refer to thermoplastic materials and therefore does not include thermosetting materials. Consequently, in this revision of the original chapter the word polymer will generally be used unless the reference is specifically to a thermoplastic material.