Plastic Recycling

Essay by jsecoursUniversity, Bachelor's November 2009

download word file, 11 pages 0.0

History:Plastic is a material that is used widely throughout the world. We can find plastic everywhere in our daily lives. It has changed our lives a great deal; however often its importance is forgotten. There are many things in today's world that are made of plastic.

Within the last years, plastic has evolved immensely. There exist more than 1,000 different plastics that vary widely and can be used for different purposes. We can define plastic "as a group of synthetic resins or other substances that can be moulded into any form" (1, p.10). Molecules determine the structural form of the plastic as well as their physical feature. Plastics are also known as polymers or resins.

A polymer is a large molecule of high molecular mass formed by the joining together of a large number of molecules of low molecular mass (2). The individual molecules forming the polymer are called monomers.

Polymers can be divided into 2 categories; extendable polymers and cross-linked polymers (1). Extendable polymers are thermoplastic and cross-linked polymers are thermoset. Both groups differ in their structure, properties, and chemical processes (1). The most important difference between both is that thermoplastic can be remelted after processing and can be remoulded where as thermoset plastics cannot be remelted. Thermoplastics are elastic and flexible; they "are the most important class of plastics material available commercially and account for more than two thirds of all polymers used in the world today" (1, p.14).

The polymer industry began in the 1870s; however the first synthetic polymer was created in 1909 by Leo Baekeland (3). Following this discovery there was a great amount of research "to understand the molecular structure of polymers" (3, p.3). In 1920, their unique properties were discovered by Hermann Staudinger although this was only accepted in 1928. "The 1930s were...