Polyhydroxy aromatic intermediate, preparation thereof and use thereof in polycondensate water-reducer with branched side chains

A polycondensate water-reducer with branched side chains, wherein the molecular structure thereof comprises three structural units, aromatic structural unit I with multiple polyether side chains, phosphate-based aromatic structural unit II, and methylene structural unit III;

• the aromatic structural unit I with multiple polyether side chains is an aromatic moiety with 2-4 polyether side chains;
• the aromatic moiety includes phenyl, methylphenyl or methoxyphenyl;
• the phosphate-based aromatic structural unit II is an aromatic moiety with 1-2 phosphonate monoester groups;
• the aromatic moiety includes phenyl, methylphenyl or methoxyphenyl, and the rest are side chains;
• the methylene structural unit III connects the aromatic structural unit with multiple polyether side chains and the phosphate-based aromatic structural unit, the connected structural units are each independently the same or different, and the methylene structural unit connects any two of the structures of the aromatic structural unit I with multiple polyether side chains and the phosphate-based aromatic structural unit II;
• the aromatic structural unit I with multiple polyether side chains is obtained from an addition reaction of the polyhydroxy aromatic intermediate F and ethylene oxide,
• the aromatic structural unit I with multiple polyether side chains is any one of general formula (Ia) or (Ib);
• wherein R1 and R2 are each independently the same or different H, C1-C4 alkyl, or C1-C4 alkoxy;
• wherein a represents an integer from 1-5, and m represents an integer from 10-50;
• wherein b represents an integer from 0-2, and n represents an integer from 10-50;
• the phosphate-based aromatic structural unit II conforms to a general formula (II):
• wherein R3 is H, C1-C4 alkyl, or C1-C4 alkoxy;
• wherein X represents O or N, and when X represents O, c=1;
• and when X represents N, c=2;
• the methylene structural unit III connects two aromatic structural units, the two aromatic structural units being independently the same or different;
• and
• the molar ratio of structural unit (Ia), structural unit (Ib), and structural unit (II) should satisfy (II)/(Ia)=0.5−8, and (II)/(Ib)=0.5−8.