Polymer emulsion capable of be flocculated by CO2 gas, preparation method and flocculation method

The invention relates to polymer emulsion capable of being flocculated by CO2 gas, a preparation method and a flocculation method, and belongs to the field of material and fine chemical engineering. The polymer emulsion comprises a monomer capable of performing free radical polymerization, an anionic emolsifier or negion-non-iron compound emulsifier, a crosslinking agent, an initiator, deionized water and an assistant and is characterized by further comprising polymer emulsion that is prepared by adding a protonated amino-containing functional monomer into the polymer emulsion and performing polymer emulsion copolymerization and has a core-shell structure, or compound polymer emulsion that is prepared by directly and physically mixing the polymer emulsion and the protonated amino-containing functional monomer. The polymer emulsion can be demulsified to achieve separation of a polymer and water only by admitting the CO2 gas without adding electrolytes such as acid, alkali and salt, and then granular polymer po