HISTORY OF PLASTICS

How Was Plastic Discovered?
Every day, plastics contribute to our health, safety and peace of mind. But how was plastic discovered? The first man-made plastic was unveiled by Alexander Parkes at the 1862 Great International Exhibition in London. This material was an organic material derived from cellulose that once heated could be molded but that retained its shape when cooled. Parkes claimed that this new material could do anything rubber was capable of, but at a lower price. He had discovered something that could be transparent as well as carved into thousands of different shapes. But this product soon lost its lustre, due to the high cost of the raw materials needed in its production.

Polyethylene
In 1933, two organic chemists working for the Imperial Chemical Industries Research Laboratory were testing various chemicals under highly pressurized conditions. In their wildest imaginations, the two researchers E.W. Fawcett and R.O. Gibson, had no idea that the revolutionary substance they would come across - polyethylene - would have an enormous impact on the world.

The researchers set off a reaction between ethylene and benzaldehyde, utilizing two thousand atmospheres of internal pressure. The experiment went askew when their testing container sprang a leak and all of the pressure escaped. Upon opening the tube they were surprised to find a white, waxy substance that greatly resembled plastic. When the experiment was carefully repeated and analyzed the scientists discovered that the loss of pressure was only partly due to a leak; the greater reason was the polymerization process that had occurred leaving behind polyethylene. In 1936, Imperial Chemical Industries developed a large-volume compressor that made the production of vast quantities of polyethylene possible. This high-volume production of polyethylene actually led to some history-making events.

For instance, polyethylene played a key supporting role during World War II - first as an underwater cable coating and then as a critical insulating material for such vital military applications as radar insulation. This is because it was so light and thin that it made placing radar onto airplanes possible; something that could not be done using traditional insulating materials because they weighed too much. In fact, the use of polyethylene as an insulating material reduced the weight of radars to 600 pounds in 1940 and even less as the war progressed. It was these lightweight radar systems, capable of being carried onboard planes, that allowed the out-numbered Allied aircraft to detect German bombers under such difficult conditions as nightfall and thunderstorms.

It was not until after the war, though, that the material became a tremendous hit with consumers and from that point on, its rise in popularity has been almost unprecedented. It became the first plastic in the United States to sell more than a billion pounds a year and it is currently the largest volume plastic in the world. Today, polyethylene is used to make such common items as soda bottles, milk jugs and grocery and dry-cleaning bags in addition to plastic food storage containers.

Plastics in Modern Life
Since the 1950s, plastics have grown into a major industry that affects all of our lives - from providing improved packaging to giving us new textiles, to permitting the production of wondrous new products and cutting edge technologies in such things as televisions, cars and computers. In fact, since 1976, plastic has been the most used material in the world and was voted one of the top 100 news events of the century.

None of the applications and innovations we take for granted would have been possible if it weren't for the early scientists who developed and refined the material. Those pioneers made it possible for us to enjoy the quality of life we do today.

Courtesy of : www.americanchemistry.com (American Chemistry Council)

PLASTICS TIMELINE

• 1839 - Natural Rubber - method of processing invented by Charles Goodyear
• 1843 - Vulcanite - Thomas Hancock
• 1843 - Gutta-Percha - William Montgomerie
• 1856 - Shellac - Alfred Critchlow, Samuel Peck
• 1856 - Bois Durci - Francois Charles Lepag

• 1839 - Polystyrene or PS discovered - Eduard Simon
• 1862 - Parkesine - Alexander Parkes
• 1863 - Cellulose Nitrate or Celluloid - John Wesley Hyatt
• 1872 - Polyvinyl Chloride or PVC - first created by Eugen Baumann
• 1894 - Viscose Rayon - Charles Frederick Cross, Edward John Bevan

• 1908 - Cellophane - Jacques E. Brandenberger
• 1909 - First true plastic Phenol-Formaldehyde tradenamed Bakelite - Leo Hendrik Baekeland
• 1926 - Vinyl or PVC - Walter Semon invented a plasticized PVC
• 1927 - Cellulose Acetate
• 1933 - Polyvinylidene chloride or Saran also called PVDC - accidentally discovered by Ralph Wiley, a Dow Chemical lab worker
• 1935 - Low-density polyethylene or LDPE - Reginald Gibson and Eric Fawcett
• 1936 - Acrylic or Polymethyl Methacrylate
• 1937 - Polyurethanes tradenamed Igamid for plastics materials and Perlon for fibers. - Otto Bayer and co-workers discovered and patented the chemistry of polyurethanes
• 1938 - Polystyrene made practical
• 1938 - Polytetrafluoroethylene or PTFE tradenamed Teflon - Roy Plunkett
• 1939 - Nylon and Neoprene considered a replacement for silk and a synthetic rubber respectively Wallace Hume Carothers
• 1941 - Polyethylene Terephthalate or Pet - Whinfield and Dickson
• 1942 - Low Density Polyethylene
• 1942 - Unsaturated Polyester also called PET patented by John Rex Whinfield and James Tennant Dickson
• 1951 - High-density polyethylene or HDPE tradenamed Marlex - Paul Hogan and Robert Banks
• 1951 - Polypropylene or PP - Paul Hogan and Robert Banks
• 1953 - Saran Wrap introduced by Dow Chemicals
• 1954 - Styrofoam the trademarked form of polystyrene foam insulation, invented by Ray McIntire for Dow Chemicals
• 1964 - Polyimide
• 1970 - Thermoplastic Polyester this includes trademarked Dacron, Mylar, Melinex, Teijin, and Tetoron
• 1978 - Linear Low Density Polyethylene
• 1985 - Liquid Crystal Polymers

POLYMERS

• Packaging film - used for fresh and frozen vegetable bags, blanket packs, soft supermarket carry-out bags, fertilizer bags, dry cleaner film, garbage bags, and the bulk of shrink - and stretch wrap films.
• Bottles - soft, squeezable bottles, soft containers, cosmetic tubes.
• Pipes - varieties of black agricultural pipes, especially for low pressure.

Low density and linear low density polyethylene (LDPE and LLDPE)

Almost all thin, slightly milky, usually transparent packaging film used for fresh and frozen vegetable bags, blanket packs, pillow and disposable nappy wraps, soft supermarket carry-out bags, fertiliser bags, dry cleaners' film packaging and for the bulk of the shrink- and stretch wrap films, black garbage bags and building film are made from LDPE/LLD. Soft, squeezable bottles, soft covers for fridge containers, the soft containers themselves and the softer varieties of black agricultural pipe are also made from LDPE/LLD.

This is the largest single type of plastic recovered in the RSA and comprises about 50% of the total amount of plastics recycled.

There is a high demand for this type of material from recyclers.