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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.
Liquid packaging board cartons typically contain 74% paper, 22% plastic and 4% aluminum. Frozen food cartons are usually made up of an 80% paper and 20% plastic combination. [8] The most notable applications for plastic-coated paper are single use (disposable food packaging): [9] Liquid packaging board for milk and juice folding cartons
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.
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]
A paper cup is a disposable cup made out of paper and often lined or coated with plastic [1] [2] or wax to prevent liquid from leaking out or soaking through the paper. [ 3 ] [ 4 ] It may be made of recycled paper .
Polyethylene terephthalate is produced largely from purified terephthalic acid (PTA), as well as to a lesser extent from (mono-)ethylene glycol (MEG) and dimethyl terephthalate (DMT). [41] [5] As of 2022, ethylene glycol is made from ethene found in natural gas, while terephthalic acid comes from p-xylene made from crude oil.
Disposable foodservice products made from paper, paperboard, and corrugated fiberboard: including cups, plates, bowls, napkins, carryout bags, trays, egg cartons, doilies and tray liners. Some paper products are coated - mostly with plastic - or treated to improve wet strength or grease