Patent ID: 9399193
Filing Date: 2016-07-26
CPC Classification: B01D,C02F,C08F,C08G,C08L

Claim Text:
1. A draw solute for forward osmosis, the draw solute comprising: a copolymer including a first structural unit and a second structural unit at a mole ratio of about 1:99 to about 10:90 of the first structural unit to the second structural unit and has a lower critical solution temperature (LCST) of about 25 to about 50° C. in water, the first structural unit including a first main chain and a first side chain, the second structural unit including a second main chain and a second side chain, the first main chain and the second main chain being directly linked to form a main chain for the copolymer, the first side chain being a temperature-sensitive side chain graft polymerized to the first main chain, the temperature-sensitive side chain including at least one side structural unit, the at least one side structural unit including a temperature-sensitive moiety, the second structural unit including a hydrophilic functional group substituted in the second main chain or the second side chain of the second structural unit, the temperature-sensitive moiety being a monovalent substituent represented by the following Chemical Formula 1, a monovalent substituent represented by the following Chemical Formula 2, or a divalent substituent represented by the following Chemical Formula 3: wherein, in the above Chemical Formula 1, R wherein, in the above Chemical Formula 2, R wherein, in the above Chemical Formula 3, R wherein the at least one side structural unit is represented by the following Chemical Formula 4, Chemical Formula 5, Chemical Formula 6, or a combination thereof: wherein, in Chemical Formulas 4 to 6, R R wherein the temperature-sensitive side chain includes n of Chemical Formula 4, Chemical Formula 5, or Chemical Formula 6, n being an integer ranging from 2 to 30.