The use of a polymer comprising side chains having a sterically hindered amine as chemical admixture for a cementitious material

A cementitious material comprising a chemical admixture comprising a polymer, the polymer having a backbone structure, the backbone structure being provided with a plurality of negatively charged groups and having a plurality of side chains, at least portion of the side chains comprising a pendent group comprising a sterically hindered amine, with the pendent group comprising

• a group of formula (I) or of formula (II)
• with
• —X1, —X2 comprising a substituted or non-substituted alkyl having 3 to 20 carbon atoms and having a secondary or tertiary carbon atom directly attached to the nitrogen atom of the group of formula (I) or of formula (II);
• —R1 comprising hydrogen or a substituted or non-substituted alkyl having 1 to 20 carbon atoms;
• or
• a heterocyclic amine A comprising at least one saturated or unsaturated closed ring comprising carbon atoms and at least one nitrogen atom in the saturated or unsaturated closed ring, with the at least one nitrogen atom of the closed ring having at least one carbon atom being part of the closed ring that is directly attached to the at least one nitrogen atom and that is substituted with at least one alkyl or substituted alkyl having 1 to 20 carbon atoms,
• with the negatively charged groups being present in an amount of x %, with x being at least 10, and
• with the side chains comprising the sterically hindered amine being present in an amount of at least 0.80·(100−x) mol %.

A cementitious composition comprising a cementitious material and a chemical admixture, the chemical admixture comprising a polymer having a backbone structure provided with a plurality of negatively charged groups and having a plurality of side chains, the at least part of the side chains comprising a pendent group comprising a sterically hindered amine, with the pendent group comprising

• a group of formula (I) or of formula (II)
• with
• —X1, —X2 comprising a substituted or non-substituted alkyl having 3 to 20 carbon atoms and having a secondary or tertiary carbon atom directly attached to the nitrogen atom of the group of formula (I) or of formula (II);
• —R1 comprising hydrogen or a substituted or non-substituted alkyl having 1 to 20 carbon atoms;
• or
• a heterocyclic amine A comprising at least one saturated or unsaturated closed ring comprising carbon atoms and at least one nitrogen atom in the saturated or unsaturated closed ring, with the at least one nitrogen atom of the closed ring having at least one carbon atom being part of the closed ring that is directly attached to the at least one nitrogen atom and that is substituted with at least one alkyl or substituted alkyl having 1 to 20 carbon atoms;
• with the negatively charged groups being present in an amount of x %, with x being at least 10, and
• with the side chains comprising a pendent group having the sterically hindered amine being present in an amount of at least 0.80·(100−x) mol %.

A polymer having a backbone structure, wherein the backbone structure has a plurality of negatively charged groups and has a plurality of side chains, at least a portion of the side chains comprising a pendent group comprising a sterically hindered amine, with the pendent group comprising:

• a group of formula (I) or of formula (II)
• with
• —X1, —X2 comprising a substituted or non-substituted alkyl having 3 to 20 carbon atoms and having a secondary or tertiary carbon atom directly attached to the nitrogen atom of the group of formula (I) or of formula (II);
• and
• —R1 comprising hydrogen or a substituted or non-substituted alkyl having 1 to 20 carbon atoms;
• or
• a heterocyclic amine A comprising at least one saturated or unsaturated closed ring comprising carbon atoms and at least one nitrogen atom in the saturated or unsaturated closed ring, with the at least one nitrogen atom of the closed ring having at least one carbon atom being part of the closed ring that is directly attached to the at least one nitrogen atom and that is substituted with at least one alkyl or substituted alkyl having 1 to 20 carbon atoms,
• with the negatively charged groups being present in an amount of x %, with x being at least 10, and
• with the side chains comprising the sterically hindered amine being present in an amount of at least 0.80·(100−x) mol %.