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LDPE has SPI resin ID code 4 Schematic of LDPE branching structure. 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]
The melting point for average commercial low-density polyethylene is typically 105 to 115 °C (221 to 239 °F). These temperatures vary strongly with the type of polyethylene, but the theoretical upper limit of melting of polyethylene is reported to be 144 to 146 °C (291 to 295 °F). Combustion typically occurs above 349 °C (660 °F).
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. Linear low-density polyethylene differs structurally from conventional low-density polyethylene (LDPE) because of the absence of long chain ...
Low-density polyethylene: 45–55: 1.0: 0.85 Density measurements ... or in samples stored for long time at temperatures just under the melting point. The latter ...
Polyethylene (polyethene, polythene, PE) is a family of similar materials categorized according to their density and molecular structure. It is also known as poly and is obtained by the addition polymerisation of ethylene. It may be of low density or high density depending upon the process used in its manufacturing.
Base polymer for EPE foams range from Low-density polyethylene (LDPE) to High-density ... autoclave at a temperature close to the plastic's crystalline melting point ...
A low density results from the chains being further apart. Lower melting points and tensile strengths are evident, because the intermolecular bonds are weaker and require less energy to break. The problem of branching occurs during propagation, when a chain curls back on itself and breaks - leaving irregular chains sprouting from the main ...
Density: 1.128 g/cm 3: Melting point: 4 to 8 °C (39 to 46 °F; 277 to 281 K) ... PEG 400 (polyethylene glycol 400) is a low-molecular-weight grade of polyethylene ...