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Infobox references. Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene. Polypropylene belongs to the group of polyolefins and is partially crystalline and non-polar.
Eduard Simon, a German apothecary, discovers polystyrene. [2] 1844. Thomas Hancock patents the vulcanization of rubber in Britain immediately followed by Charles Goodyear in United States. [3] 1856. Parkesine, the first member of the Celluloid class of compounds and considered the first man-made plastic, is patented by Alexander Parkes. [4] 1869.
J. Paul Hogan. John Paul Hogan (August 7, 1919 [1] – February 19, 2012) [2][3] was an American research chemist. Along with Robert Banks, he discovered methods of producing polypropylene and high-density polyethylene. [1]
In the European Union (EU), too, heavy investments have been made in the plastics industry, which employs over 1.6 million people with a turnover of more than 360 billion euros per year. In China in 2016 there were over 15,000 plastic manufacturing companies, generating more than US$366 billion in revenue.
Observed concentrations have been in the range of 0.1–4.8 parts per billion in rural air, 4–10.5 ppb in urban air, and 7–260 ppb in industrial air samples. [9] In the United States and some European countries a threshold limit value of 500 parts per million was established for occupational (8-hour time-weighted average) exposure.
In 1996, Monsanto discovered a method of producing one of the two polymers in plants and acquired Biopol from Zeneca, a spinout of ICI, as a result of the potential for cheaper production. [ 11 ] As a result of the steep increase in oil prices in the early 2000s (to nearly $140/barrel US$ in 2008), the plastic-production industry finally sought ...
Earth formed in this manner about 4.54 billion years ago (with an uncertainty of 1%) [25] [26] [4] and was largely completed within 10–20 million years. [27] In June 2023, scientists reported evidence that the planet Earth may have formed in just three million years, much faster than the 10−100 million years thought earlier.
The history of materials science is the study of how different materials were used and developed through the history of Earth and how those materials affected the culture of the peoples of the Earth. The term "Silicon Age" is sometimes used to refer to the modern period of history during the late 20th to early 21st centuries.