Low foaming hydraulic fluids having biodegradable polyalkylene glycol rheology modifiers useful in subsea applications
AssigneeDow Global Technologies LLC
InventorsMartin R. Greaves, Jochem Kersbulck
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Abstract
A composition comprising water and a polyalkylene glycol having an allyl content of less than 20 μeq/g, which composition has reduced foaming properties and preferably a biodegradability of at least 60% as determined using OECD 301F. The polyalkylene glycol can be made by forming a first intermediate comprising an oxypropylene block by reacting propylene oxide with a polyol initiator in the presence of a Double Metal Cyanide catalyst, and then reacting the first intermediate with ethylene oxide in the presence of a KOH catalyst.
Claims9
An aqueous composition comprising a polyalkylene glycol block copolymer wherein the polyalkylene glycol has a molecular weight of no more than 4000 g/mol and is characterized in that it is an oxyethylene/oxypropylene block copolymer having a weight percent of oxyethylene of at least 20% based on total weight of the copolymer and an allyl content of less than 20 μeq/g.
Dependencies are inferred from the claim text.