US 11,891,458 B2
Starch-containing microsphere and preparation method and use thereof
Chao Yang, Liaoning (CN); Chen Wang, Liaoning (CN); Zequn Yin, Liaoning (CN); and Quanjie Liu, Liaoning (CN)
Assigned to CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); and DALIAN RESEARCH INSTITUTE OF PETROLEUM AND PETROCHEMICALS, SINOPEC CORP., Liaoning (CN)
Filed by CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); and DALIAN RESEARCH INSTITUTE OF PETROLEUM AND PETROCHEMICALS, SINOPEC CORP., Liaoning (CN)
Filed on Apr. 6, 2022, as Appl. No. 17/658,173.
Application 17/658,173 is a division of application No. 16/641,504, abandoned, previously published as PCT/CN2018/101771, filed on Aug. 22, 2018.
Claims priority of application No. 201710720844.7 (CN), filed on Aug. 22, 2017; application No. 201710720850.2 (CN), filed on Aug. 22, 2017; application No. 201710720851.7 (CN), filed on Aug. 22, 2017; application No. 201710720862.5 (CN), filed on Aug. 22, 2017; application No. 201710720863.X (CN), filed on Aug. 22, 2017; and application No. 201710720864.4 (CN), filed on Aug. 22, 2017.
Prior Publication US 2022/0227893 A1, Jul. 21, 2022
Int. Cl. C08B 31/00 (2006.01); C08B 31/12 (2006.01); C09K 8/42 (2006.01); E21B 21/00 (2006.01); E21B 33/13 (2006.01); E21B 33/138 (2006.01)
CPC C08B 31/003 (2013.01) [C08B 31/12 (2013.01); C09K 8/426 (2013.01); E21B 21/003 (2013.01); E21B 33/138 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for preparing starch-containing microspheres, comprising:
(1) adding a first cross-linking agent, a polymerizable monomer, and an initiator into an aqueous solution comprising starch and a solubilizer to carry out a cross-linking reaction at 60-80° C. for 3-6 h to form a first mixture;
(2) mixing a zwitterionic surfactant into the first mixture to form a second mixture;
(3) adding a second cross-linking agent and an inorganic salt into the second mixture at 30-60° C. to form starch-containing microspheres in the second mixture; and
(4) filtering the second mixture and drying a residue to obtain the starch-containing microspheres,
wherein the first cross-linking agent and the second cross-linking agent are each independently selected from epoxy chloropropane, phosphorus oxychloride, sodium trimetaphosphate, adipic acid, sodium hexametaphosphate, and mixtures thereof,
wherein the second cross-linking agent and the inorganic salt are in one solution being added to the second mixture or in two different solutions being simultaneously added to the second mixture,
wherein the polymerizable monomer is one or more of a cationic monomer, an anionic monomer, a zwitterionic monomer, and a nonionic monomer,
the cationic monomer being one or more of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl dimethyl benzyl ammonium chloride, dimethyl diallyl ammonium chloride, and diethyl diallyl ammonium chloride;
the anionic monomer being one or more of acrylic acid, 2-methyl-2-acrylamido propanesulfonic acid, fumaric acid, sodium allyl sulfonate, and sodium 2-acryloyloxy isopentene sulfonate;
the zwitterionic monomer being one or more of methacryloyloxyethyl-N, N-dimethyl propane sulfonate, N, N-dimethyl allyl amine propane sulfonate, 4-vinylpyridine propane sulfonate, N-methyl diallyl propane sulfonate, and N-methyl diallyl butane sulfonate; the nonionic monomer is one or more of N-vinyl pyrrolidone, acrylonitrile, vinyl formamide, and vinyl acetamide; and
the initiator being potassium persulfate, sodium persulfate, or ammonium persulfate, wherein the starch is selected from mung bean starch, tapioca starch, ipomoea batatas starch, sweet potato starch, potato starch, wheat starch, water chestnut starch, lotus root starch, corn starch, and mixtures thereof, and
wherein the solubilizer is selected from trimethanolamine, triethanolamine, tripropanolamine, and N, N-bisdiethanol amine.