A process for preparing powdered dispersants comprising at least 90% by weight of at least one copolymer CP of the polycarboxylate ether type. The powdered dispersants can be easily dispersed in water. The invention also relates to the use of such powdered dispersants in mineral binder compositions, in particular dry mortars, concrete or gypsum formulations.

A process for preparing powdered dispersants comprising at least 90% by weight of at least one copolymer CP of the polycarboxylate ether type. The powdered dispersants can be easily dispersed in water. The invention also relates to the use of such powdered dispersants in mineral binder compositions, in particular dry mortars, concrete or gypsum formulations.

A composition may be suitable for flowable refractory materials and include calcium aluminate cement, a filler, a plasticizer in the form of a copolymer comprising polyether side chains, and a retarder having at least one acid. An article may include such a composition.

A composition may be suitable for flowable refractory materials and include calcium aluminate cement, a filler, a plasticizer in the form of a copolymer comprising polyether side chains, and a retarder having at least one acid. An article may include such a composition.

A copolymer may be obtained by polymerization reaction(s) using an anionic monomer and two polyethoxylated monomers. Such copolymers may have a polydispersity index, determined by size exclusion chromatography (SEC), of less than 3, and be obtained by at least one radical polymerisation reaction in water at a temperature ranging from 10 to 90° C. A composition may include such copolymers. Such copolymers may be prepared and use as a superplasticizer for a hydraulic binder composition.

A dispersant composition includes a) at least one polymer constituted of monomers having naphthalene ring and/or melamine; b). at least one polymer having carboxylic acid and/or phosphoric acid group and/or any group that is hydrolyzed into carboxylic or phosphoric; and c). at least one polymer having a structure of Formula I: ##STR00001##
R.sup.1 is hydrogen or alky group having carbon number not less than 1, cycloalkyl or cycloalkenyl group having carbon number not less than 3, alkenyl group having carbon number not less than 2, aryl group having carbon number not less than 6; R.sup.2 is hydrogen or alky group having carbon number from 1 to 3; A is alkylene group having carbon number from 3 or 4; m and n are positive numbers wherein m is more than n and the sum of m and n is more than 9 and less than 12. Also provided is a method of using the dispersant composition in a mortar or concrete, and the weight percentage of the dispersant composition is from 0.01% to 2.5% based on the weight of cement in mortar. Further provided is an aqueous composition including the dispersant composition.

A dispersant composition includes a) at least one polymer constituted of monomers having naphthalene ring and/or melamine; b). at least one polymer having carboxylic acid and/or phosphoric acid group and/or any group that is hydrolyzed into carboxylic or phosphoric; and c). at least one polymer having a structure of Formula I: ##STR00001##
R.sup.1 is hydrogen or alky group having carbon number not less than 1, cycloalkyl or cycloalkenyl group having carbon number not less than 3, alkenyl group having carbon number not less than 2, aryl group having carbon number not less than 6; R.sup.2 is hydrogen or alky group having carbon number from 1 to 3; A is alkylene group having carbon number from 3 or 4; m and n are positive numbers wherein m is more than n and the sum of m and n is more than 9 and less than 12. Also provided is a method of using the dispersant composition in a mortar or concrete, and the weight percentage of the dispersant composition is from 0.01% to 2.5% based on the weight of cement in mortar. Further provided is an aqueous composition including the dispersant composition.

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.

The invention relates to a composite formulation comprising a specific mediator additive component (A) of relatively high molecular weight, a filler component (B) and a binder component (C). The composite formulation can be cured to a composite which is especially suitable for the production of moldings.

The present invention relates to an additive for hydraulically setting compositions, comprising a colloidally disperse preparation of at least one salt of a mono- or polyvalent metal cation and of at least one compound which is able to release an anion which forms a low-solubility salt with the metal cation, and of at least one polymeric sulphonated dispersant. The additive is suitable particularly as a slump retainer.