Back to results
US 11,879,031 B2Granted
Low critical solution temperature purification of oxazoline polymer solutions
AssigneeSolenis Technologies, L.P.
InventorDaniel F. Varnell
Life of this patent
Estimating the term…
Abstract
Provided are methods for the purification of polymer solutions. In particular, the method enables the separation of impurities from an oxazoline polymer solution by raising the temperature of the polymer solution above its lower critical solution temperature (LCST), wherein a water rich phase and a polymer rich phase separation occurs. The phases are then separated with the polymer rich phase containing a lower amount of impurities than before separation.
Claims20
A method for the purification of a polymer solution comprising the steps of:
- a) providing a polymer solution comprising water and an oxazoline polymer having a weight average molecular weight greater than about 5000 g/mol, and one or more impurities,
- b) raising the temperature of the polymer solution from a first temperature to a second temperature that is above a lower critical solution temperature (LCST), wherein the polymer solution separates into a predominantly water phase and a polymer-rich phase;
- c) separating the water phase from the polymer phase;
- d) cooling the polymer phase to a third temperature such that a purified soluble polymer solution forms and has an amount of the one or more impurities that is less than an amount of the one or more impurities present in the polymer solution;
- and
- e) optionally repeating steps b), c) and d).
3 more elements
A method for the purification of poly-2-ethyl oxazoline (PEOx) comprising the steps of:
- a) providing an aqueous solution containing one or more impurities and PEOx;
- b) raising the temperature of the aqueous solution from a first temperature to a second temperature that is a lower critical solution temperature, wherein the aqueous solution separates into a water phase and a polymer rich phase;
- c) separating the polymer rich phase from the water phase;
- wherein the polymer rich phase is more dense and contains a predominance of the PEOx polymer and the water phase contains a portion of the one or more impurities;
- d) cooling the polymer phase to a third temperature allowing the polymer phase to return to an aqueous solution;
- and
- e) optionally repeating steps b), c) and d).
4 more elements
Dependencies are inferred from the claim text.