The first man-made plastic, a form of cellulose nitrate, was prepared in 1838 by A. Parker and shown at the Great International Exhibition in London in 1862. It was intended to be a replacement for natural materials such as ivory and was called parkesine. In 1840, Goodyear and Hancock developed the “vulcanization” procedure that eliminated tackiness and added elasticity to nature rubber. The change in the properties of the nature rubber was obtained by addition of sulfur powder that produced additional chemical bonds in the bulk of the rubber.

In 1851, hard rubber, or ebonite, was commercialized. In 1870 a patent was issued to J. Hyatt, of New York, for celluloid, a type of cellulose nitrate with low nitrate content produced at high temperature and pressure. This was the first commercially available plastic, and they only one until the development of Bakelite by Baekeland in 1907. Bakelite is the oldest of the purely synthetic plastics and consisted of a resin obtained by the reaction of phenol and formaldehyde.

The exact nature of plastics, rubber, and similar natural materials was not known until 1920, when H.Staudinger proposed a revolutionary idea: all plastics, rubber, and materials such as cellulose were polymers, or macromolecures. Before Staudinger’s theory, the scientific community was very confused about the exact nature of plastics, rubbers and other materials of very high molecular weight. To most research workers in the 19th century, the finding that some materials had a molecular weight in excess of 10,000g/mol appeared to be untrustworthy. They confused such substances with colloidal systems consisting of stable suspensions of small molecules.

Staudinger rejected the idea that these substances were organic colloids. He hypothesized that the high molecular weight substances know as polymers were ture macromolecules formed by covalent bonds. Staudinger’s macromolecule theory stated the polymers consist of long chains in which the individual monomers (or building block) are connected with each other by normal covalent bonds. The unique polymer properties are a consequence of high molecular weight and long chain nature of the macromolecule. While at first hypothesis was not readily accepted by most scientists, it eventually became clear that this explanation permitted the rational interpretation of experiments and so gave to industrial chemists a firm guide for their work. An explosion in the number of polymers followed Staudinger was awarded the Nobel Prize in 1953, it is well established now that plastics, as well as many other substances such as rubber, cellulose, and DNA, are macromolecules.

Since 1930, the growth in the number of polymers and their applications has been immense. During the 1930s, industrial chemical companies initiated fundamental research programs that had a tremendous impact on our society. For example, Wallace, Carothers, working at Dupont de Nemours and Co., development diverse polymeric materials of defined structures and investigated how the properties of these materials depend on their structure. In 1939 this program resulted in the commercialization of nylon.

A commercial process for the synthesis of polyethylene was successfully developed in the 1930s by ICI (Imperial Chemical Industrials), England. In 1955, K Ziegler in Germany and J. Natta in Italy developed processes for making polyethylene at low pressure and temperature using special catalysts. They were awarded the Nobel Prize, Ziegler in 1964 and Natta in 1965, for their contributions in the development of new polymerization catalysts with unique stereo-regulating powers. Linear polyethylene producing using solution and gas technologies as introduced in the 1970s. The continuous development of new polymers resulted in additional breakthroughs in the mid-1980s and early 1990s. Single-site catalysts, which were originally discovered by Natta in the mid-1950s, were commercialized for syndiotactic polystyrene in 1954, polypropylene in 1984, and polyethylenes in the early 1990s. These catalysts permit much greater control over the molecular weight and architecture of polyolefins such as polyethylene and polypropylene.

Today, dozens of different synthetic plastics are produced throughout the world by hundreds of companies. In North American alone, plastics production 1n 2003 totaled about million tones (107 billion Ibs). Packaging is the largest single market for plastics, amounting to about 13 million tones (28 billion Ibs) per year, about a quarter of total U.S plastics production, in 2003.