I want to say one word to you.
Are you listening ?
Yes sir, I am.
- The Graduate
1. Definition of Plastics
Plastics can be defined as used materials which are primarily based on two materials, polymers and prepolymers (Elias, 1993). However, the previously mentioned definition suffers from a serious weakness as it does not explain the basic method of how plastics are made. A better definition of plastics is that they are “synthetic materials composed of a series or chain of molecules which, when heat or pressure is applied, can be formed into desired shapes” (Lincoln et al. 1984, p6). The reason they were named “plastics” is because they are easily processed and shaped. This name was originally derived from the greek word "Plastein" which fundamentally means to form or to shape.
1.2. Definition and Description of Polymers
Polymers, which are considered to be raw materials for plastics, are a wide group of substances that may be classified into three categories: organic such as nucleic acids, semi-organic such as born nitride, concrete and many high-temperature superconductors and inorganic chemical substances such as diamonds, sands and chert (McGraw-Hill Professional, 2007, p162). Organic polymers can also be exemplified by cotton, cellulose in plants and/or skin, hoofs and muscle (Ruoff, 1972). The name polymers was originally came from the two Greek words, “poly” which means many and “meros” which means parts. The difference between polymers and prepolymers is that a prepolymer has lower moral masses than a polymer does. Prepolymers can be exactly the same as polymers on processing (Elias, 1993).
2. The History of Plastics
In terms of history, plastics have been used since ancient times in spite of the fact that they are generally considered to be modern developments compared to other materials. Elias (1993) argued that polymers have been around for a long time in nature, such as egg-whites and blood proteins used in the cave paintings of Altamira. Another natural polymer is horns which were used to produce limpid windows for lanterns in the medieval ages (between 1000 and 1500). These horns were based entirely on a protein named casein which was extracted from skimmed milk and shaped after that to become an early thermoset. Later, unknown inventors found out that the mechanical stability of this thermoset can be increased with the addition of inorganic fillers.
2.1 The First Thermosetting Plastics
In 1906, the first completely artificial thermosetting plastic was created by the Belgian-born American chemist Baekeland who demonstrated that when different phenols are heated with formaldehyde under pressure that leads to insoluble strong masses. This thermosetting phenol formaldehyde resin was named Bakelite and considered in 1909 as one of the most basic parts of the modern electrical industry owing to its excellent electrical...