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The Phillips catalyst, or the Phillips supported chromium catalyst, is the catalyst used to produce approximately half of the world's polyethylene. A heterogeneous catalyst, it consists of a chromium oxide supported on silica gel. [1] Polyethylene, the most-produced synthetic polymer, is produced industrially by the polymerization of ethylene:
The reaction results in a polymer which is also soluble in the chosen solvent. Heat released by the reaction is absorbed by the solvent, reducing the reaction rate. Moreover, the viscosity of the reaction mixture is reduced, preventing autoacceleration at high monomer concentrations. A decrease in viscosity of the reaction mixture by dilution ...
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.
d is the average particle size, k includes parameters related to the reaction vessel design, D v is the reaction vessel diameter, D s is the diameter of the stirrer, R is the volume ratio of the monomer to the liquid matrix, N is the stirring speed, ν m and ν l are the viscosity of the monomer phase and liquid matrix respectively, ε is the ...
1-octene. Octene is an alkene with the formula C 8 H 16.Several isomers of octene are known, depending on the position and the geometry of the double bond in the carbon chain.. The simplest isomer is 1-octene, an alpha-olefin used primarily as a co-monomer in production of polyethylene via the solution polymerization process.
A polyolefin is a type of polymer with the general formula (CH 2 CHR) n where R is an alkyl group. They are usually derived from a small set of simple olefins ().Dominant in a commercial sense are polyethylene and polypropylene.
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.
An example of a synthetically useful Norrish type II reaction can be found early in the total synthesis of the biologically active cardenolide ouabagenin by Phil Baran and coworkers. [15] The optimized conditions minimize side reactions, such as the competing Norrish type I pathway, and furnish the desired intermediate in good yield on a multi ...