DEFINITION
Although the terms polymer, plastics, and resin are not technically the same, they are used interchangeably in the plastics processing industry. The word polymer can be broken down into two parts, ‘poly’ meaning many, and ‘mer’ meaning unit.
Although there are many different types and classifications of plastics, all polymers share three common factors.
Polymers are organic in nature, have high molecular weights, and have the ability to change shape. Any substance which contains carbon molecules is considered to be organic. Most polymers are comprised mainly of carbon and hydrogen.
Polymers have high molecular weights because they are made up of many large molecules. For example, water molecules have a molecular weight of 18 while polyethylene can have a molecular weight of over one million.
All polymers have the ability to change shape। This property allows the material to be processed into a useable product. An example of polymers changing shape is injection moulding. In injection moulding, the solid polymer pellets are melted and then moulded into the shape of the final part.
Polymerisation
Polymerisation is the process by which polymers are made. The process of polymerisation involves converting many single organic units into long polymer chains or one large polymer matrix.
Some polymers, called copolymers, are long chains comprised of two or more polymer chains. An example of a copolymer is ABS.
