Water-soluble trithiocarbonate RAFT agent, preparation method and application thereof

Abstract

The invention provides a water-soluble trithiocarbonate RAFT agent, a preparation method and application thereof. The preparation method includes: dissolving potassium hydroxide in distilled water, and after potassium hydroxide is completely dissolved, adding thiolactic acid and performing stirring; adding carbon disulfide to obtain an orange-yellow solution, and performing stirring; adding potassium hydroxide, trichloromethane, acetone and a phase transfer catalyst into the obtained solution, performing stirring at the same temperature, and adding concentrated hydrochloric acid for acidification reaction; and then, carrying out liquid separation and filtration on the obtained solution to remove oily substances and insoluble substances, and carrying out evaporative crystallization, performing suction filtration and drying to obtain the S-(2-propionic acid)-S'-(2-methyl propionic acid)trithiocarbonate water-soluble trithiocarbonate RAFT agent. According to the water-soluble RAFT agent prepared by the invention, a plurality of water-soluble groups carboxyl (COOH) are introduced, so that the water solubility of a chain transfer agent is improved, a nano-scale gel dispersion can be prepared by an RAFT aqueous solution polymerization one-pot method, the preparation process of a profile control and flooding agent is simplified, and the problem of relatively large particle size of a common profile control and flooding agent is solved; and the problem of environmental pollution caused by the use of an organic solvent is effectively avoided.

Description

technical field [0001] The invention belongs to the technical field of control and flooding, and in particular relates to a water-soluble trithiocarbonate RAFT agent and its preparation method and application. Background technique [0002] The control and flooding technology requires that the plugging agent can enter the low-permeability formation with higher oil saturation, be able to generate a certain flow resistance, and have the ability to move to deeper formations. At present, the control and drive agents that can meet the above requirements are mainly millimeter, micron, or nanoscale granular materials prepared from acrylamide. However, the preparation process of these traditional control and drive agents often requires peristaltic stirring, mechanical pulverization or reverse emulsion Polymerization methods, etc., so its preparation process is relatively complicated, and its particle size is generally large. [0003] One-pot preparation of gel polymer or dispersion ...

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Problems solved by technology

[0004] ZL201910195824.1 discloses a reversible addition-fragmentation chain transfer agent and its preparation method and application. The RAFT chain transfer agent is used to prepare a gel dispersion with a smaller particle size, which effectively solves the molecular particle size of the drive agent. The problem of too large and poor transport capacity

However, the RAFT chain transfer agent is also an oil-soluble chain transfer agent and can only be polymerized in an organic solvent, which has certain environmental pollution and economic benefits, and also limits its wide application in the field of control and flooding.

[0005] ZL201910704905.X discloses a water-soluble RAFT chain transfer agent and its preparation method and application. The chain transfer agent effectively solves the problem that RAFT polymerization is difficult to polymerize under aqueous phase conditions, and can prepare micron-sized gel dispersions in one pot , but in the preparation process of the chain transfer agent, the reactant α-bromophenylacetic acid is expensive, which is not conducive to wide application in industry, and the reaction needs to be synthesized in complex ways such as long-term reflux heating. It is the chemical shift of the hydrogen of the compound itself, so there is a problem of product impurity, and the gel dispersion prepared based on the chain transfer agent has a molecular scale of micron level and a relatively large particle size

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