The present invention relates to the use of a copolymer as a dispersant for binder compositions based on calcium sulfate, the copolymer having a polymer backbone and sidechains bound thereto, and at least one ionizable monomeric unit M1 and at least one sidechain-carrying monomeric unit M2, characterized in that the copolymer has, in a direction along the polymer backbone, a non-random distribution of the monomeric units M1 and/or of the monomeric units M2.

This document relates to methods for improving the tensile and elastic properties of cement of an oil well using cement compositions that contain sliding-ring polymer additives. The cement compositions containing the sliding-ring polymer additives exhibit increased stiffness while having a minimum impact on compressive strength, as compared to the same cement without the sliding-ring polymer additive.

This document relates to methods for preventing or inhibiting the formation of micro-cracks and fractures in the cement of an oil well using cement compositions that contain cross-linked polyrotaxane additives. The cement compositions containing the cross-linked polyrotaxane additives exhibit increased stiffness without suffering a decrease in compressive strength, as compared to the same cement without the cross-linked polyrotaxane additive.

Copolymers that comprise salicylic acid derivative structural units and structural units having free polyether side chains. The copolymers are suitable to plasticize inorganic binder systems, construction chemical compositions comprising the copolymers and the use of the copolymers as a plasticizer for inorganic binder systems. Binder systems with a reduced amount of Portland cement comprising at least one copolymer of the invention provide a better liquefaction and processability as compared to the binder systems without a copolymer of the invention.

The present invention relates to surface-modified polyolefin fibers, the use of these fibers in hydraulic binder compositions, hydraulic binder compositions containing these fibers and a method for reinforcing hydraulic binder compositions.

The present invention relates to surface-modified polyolefin fibers, the use of these fibers in hydraulic binder compositions, hydraulic binder compositions containing these fibers and a method for reinforcing hydraulic binder compositions.

The invention relates to a process for producing a pulverulent composition comprising at least one polymeric dispersant (PD) which comprises structural units having anionic and/or anionogenic groups and structural units having polyether side chains, and at least one polysaccharide (PS). The process here comprises the process steps: a) production of an aqueous dispersion having a viscosity of the dispersion of less than 10 000 mPa.Math.s, comprising the at least one polymeric dispersant (PD) and the at least one polysaccharide (PS) and b) spray drying of the aqueous dispersion produced in process step a). Furthermore, the use of the pulverulent composition according to the invention in inorganic binder compositions, especially as a rheological additive, is disclosed.

The invention relates to a process for producing a pulverulent composition comprising at least one polymeric dispersant (PD) which comprises structural units having anionic and/or anionogenic groups and structural units having polyether side chains, and at least one polysaccharide (PS). The process here comprises the process steps: a) production of an aqueous dispersion having a viscosity of the dispersion of less than 10 000 mPa.Math.s, comprising the at least one polymeric dispersant (PD) and the at least one polysaccharide (PS) and b) spray drying of the aqueous dispersion produced in process step a). Furthermore, the use of the pulverulent composition according to the invention in inorganic binder compositions, especially as a rheological additive, is disclosed.

A preparation method of a powdery polycarboxylate superplasticizer is provided, including: mixing a superplasticizer monomer with water to produce a mixture, heating and melting the mixture to produce a melt system; carrying out a bulk polymerization reaction by adding an initiator, a chain transfer agent and an unsaturated carboxylic acid into the melt system, forming a polycarboxylate superplasticizer precursor; and neutralizing and pulverizing the polycarboxylate superplasticizer precursor to produce a powdery polycarboxylate superplasticizer. Water is added in the bulk polymerization and reacts with the superplasticizer monomer and the unsaturated carboxylic acid. While the bulk polymerization reaction is guaranteed to be efficiently carried out and the solid polycarboxylate superplasticizer is formed, the viscosity of a bulk polymerization reaction system is reduced. The superplasticizer is suitable for dry-mixed mortar, high-efficiency concrete and other products.

A preparation method of a powdery polycarboxylate superplasticizer is provided, including: mixing a superplasticizer monomer with water to produce a mixture, heating and melting the mixture to produce a melt system; carrying out a bulk polymerization reaction by adding an initiator, a chain transfer agent and an unsaturated carboxylic acid into the melt system, forming a polycarboxylate superplasticizer precursor; and neutralizing and pulverizing the polycarboxylate superplasticizer precursor to produce a powdery polycarboxylate superplasticizer. Water is added in the bulk polymerization and reacts with the superplasticizer monomer and the unsaturated carboxylic acid. While the bulk polymerization reaction is guaranteed to be efficiently carried out and the solid polycarboxylate superplasticizer is formed, the viscosity of a bulk polymerization reaction system is reduced. The superplasticizer is suitable for dry-mixed mortar, high-efficiency concrete and other products.