History of plastics (part 2 of 2)
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Despite the popularity and suitability of plastics, it has constantly been subjected to trenchant criticisms. Hence the role and the chemistry of plastics, and its impact on the society and the environment becomes an apparent issue. POLYMERS: THE BASICS: As defined by the Webster s Dictionary, plastic are any of various complex organic compounds produced by polymerization, capable of being molded, extruded, cast into various shapes and films, or drawn into filaments used as textile fibers. Plastics have a very unique chemical structure, as they are composed of long-chain molecules, which contain small groups of recurring atoms linked together. Chemically speaking, such giant molecule chains are called polymers, where these long polymer molecules become entangled with each other. The word, polymer, refers to something made of many units. Each link of this long chain is a basic unit or a monomer, encompassed with organic materials, such as the elements; carbon, hydrogen, nitrogen, chlorine and sulphur. In order to form the polymer chain, many monomers are hooked or polymerized together. This process of polymerization is a chemical reaction usually in the presence of a catalyst, which combines single molecules into long-chain molecules. Though a considerable amount of force is required to disentangle the polymer chains, but when subjected to heat these chains move apart to permit one to slide over the other yet still retain their cohesiveness. Since polymers are very large and very complex molecules, the chemistry of their formation remains very complex.
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