Search results
Results from the WOW.Com Content Network
Polyethylene was first synthesized by the German chemist Hans von Pechmann, who prepared it by accident in 1898 while investigating diazomethane. [12] [a] [13] [b] When his colleagues Eugen Bamberger and Friedrich Tschirner characterized the white, waxy substance that he had created, they recognized that it contained long −CH 2 − chains and termed it polymethylene.
Parkesine, the first member of the Celluloid class of compounds and considered the first man-made plastic, is patented by Alexander Parkes. [4] 1869: John Wesley Hyatt discovers a method to simplify the production of celluloid, making industrial production possible. 1872: PVC was accidentally synthesized in 1872 by German chemist Eugen Baumann ...
Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. It was the first grade of polyethylene, produced in 1933 by John C. Swallow and M.W Perrin who were working for Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerization. [1] Its manufacture employs the same method today.
1884 Merrill & Houston builds 5 paper machines. 1885 J. D. Rexford of Janesville, Wisconsin, offers a successful bid of $20,000 for the assets of Merrill & Houston Iron works. Four ex-employees of Merrill and Houston combine to form a new company. They name the new company Beloit Iron Works. The new company has 10 employees and 4 working officers.
Polythene is the world's most widespread polymer, and was first produced by ICI from 1939; many plastic bottles are made from LDPE. Polystyrene was invented in Germany in 1937. PTFE was discovered in America (New Jersey) in 1938 by Roy J. Plunkett when at DuPont. PET beverage bottles were introduced from 1973. PEEK was developed by ICI in 1977.
HDPE is known for its high strength-to-density ratio. [4] The density of HDPE ranges from 930 to 970 kg/m 3. [5] Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. [6]
According to Al-Nadim, a writer in Baghdad during the 10th century, Chinese craftsmen made paper in Khorasan: [36] Then there is the Khurasani paper made of flax, which some say appeared in the days of the Umayyads, while others say it was during the Abbasid regime. Some say that it was an ancient product and others say that it is recent.
Linear low-density polyethylene (LLDPE) granules. Linear low-density polyethylene (LLDPE) is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins.