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The ingredient or monomer is ethylene (IUPAC name ethene), a gaseous hydrocarbon with the formula C 2 H 4, which can be viewed as a pair of methylene groups (− CH 2 −) connected to each other. Typical specifications for PE purity are <5 ppm for water, oxygen, and other alkenes contents.
styrene (C 6 H 5 CH=CH 2) which leads to polystyrene; Epoxide monomers may be cross linked with themselves, or with the addition of a co-reactant, to form epoxy; BPA is the monomer precursor for polycarbonate; Terephthalic acid is a comonomer that, with ethylene glycol, forms polyethylene terephthalate. Dimethylsilicon dichloride is a monomer ...
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]
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene (HMPE), it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. [1]
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.
To clarify, the polymer is named using the polymer class name followed by a colon and the name of the monomer, i.e., class name:monomer name. Thus on the left and right, respectively, are polyalkylene:vinyloxirane and polyether:vinyloxirane.
It produces and markets olefins and co-products, polyethylene and polypropylene, propylene oxide and derivatives, oxyfuels and related products, and intermediate chemicals, such as styrene monomer ...
The degradation of polyethylene occurs by random scission—a random breakage of the bonds that hold the atoms of the polymer together. When heated above 450 °C, polyethylene degrades to form a mixture of hydrocarbons. In the case of chain-end scission, monomers are released and this process is referred to as unzipping or depolymerization ...