For example, polyethylene is the polyolefin produced by polymerizing the olefin ethylene. Solutions containing ruthenium trichloride are highly active for olefin metathesis. Polypropylene is another common polyolefin which is made from the olefin propylene. Excess ethylene and olefin diluent are flashed off. In the Phillips Triolefin or Olefin conversion technology propylene is interconverted with ethylene and 2-butenes. The oligomerization reaction produces an optically active branched olefin using an optically active catalyst. Tyvek is a nonwoven product consisting of spun bond olefin fiber. Grubbs catalysts are of interest for olefin metathesis. Three key rearrangement reactions are 1,2-rearrangements, pericyclic reactions and olefin metathesis. Examples of thermoplastic olefin elastomers (TPO) compound are For-Tec E or Engage. There are two types of polymers that can be used in olefin fibers. The mechanism of ROMP is similar to any olefin metathesis reaction. Benzoquinone is also used to suppress double-bond migration during olefin metathesis reactions. The mechanism for ROMP follows similar pathways as olefin metathesis. The technology is founded on an olefin metathesis reaction discovered at Phillips Petroleum Company.