Branched polycarboxylate ethers

The invention relates to branched polyether macromonomers, which comprise structural units, derived by copolymerisation of alkylene oxides and glycol glycidyl ethers. It relates to a method of manufacturing a polyether macromonomer wherein either in a polyaddition reaction an unsaturated alcohol is reacted with an alkylene oxide and an glycol glycidyl ether, or a branched mono hydroxy polyalkylenoxide, derived by polyaddition of alkylene oxides with alkylene glycol glycidyl ethers is esterified with (meth)acrylic acid. It further comprises a (co)polymer containing structural units being derived from the polyether macromonomers. As methods of use of the (co)polymers in aqueous mixtures of inorganic particles are concerned the use as dispersant, as a means for reduction of the viscosity of concrete and as grinding aid for the production of (Portland) cement. The invention concerns also building material mixtures containing a (co)polymer according to this invention.