Embodiments of the disclosure include swellable smart gel sealants and methods of using smart gel sealants. In certain embodiments, the smart gel sealants reversibly swell when exposed to a certain trigger, such as carbonic acid and/or sulfuric acid. In specific embodiments, the smart gel is comprised within a cement composition.

The present invention discloses a multi-arm polycarboxylate water reducer and a preparation method thereof, the preparation method includes the following steps: making a phenolic hydroxyl containing rigid compound and p-nitrobenzonitrile subjected to a nucleophilic substitution reaction in a solvent, then subjected to addition with a sodium azide in a solvent and water mixed solution to obtain a tetrazole derivative; making an unsaturated polyether macromonomer subjected to terminal halogenation and react with the prepared tetrazole derivative to obtain a tetrazole-containing multi-arm unsaturated polyether macromonomer; and subjecting the tetrazole-containing multi-arm unsaturated polyether macromonomer, an unsaturated carboxylic acid small monomer and an unsaturated polyether macromonomer to a free radical polymerization reaction under combined action of an initiator, a reducing agent and a molecular weight regulator to obtain the multi-arm polycarboxylate water reducer integrating shrinkage reducing and antibacterial functions.

A hardener composition can be used for a reactive resin system containing a reactive resin based on radically curable, ethylenically unsaturated compounds. The hardener composition contains a hardener for the reactive resin and a filler mixture. The filler mixture is composed of a first filler having a first average particle size d.sub.50,1 and a second filler having a second average particle size d.sub.50,2. The first average particle size d.sub.50,1 of the first filler is greater than the second average particle size d.sub.50,2 of the second filler (d.sub.50,1>d.sub.50,2). The ratio d.sub.50,1 to d.sub.50,2 (d.sub.50,1:d.sub.50,2) is in the range of 8:1 to 100:1. The filler mixture is useful, and a reaction resin system can contain the hardener composition.

A hardener composition can be used for a reactive resin system containing a reactive resin based on radically curable, ethylenically unsaturated compounds. The hardener composition contains a hardener for the reactive resin and a filler mixture. The filler mixture is composed of a first filler having a first average particle size d.sub.50,1 and a second filler having a second average particle size d.sub.50,2. The first average particle size d.sub.50,1 of the first filler is greater than the second average particle size d.sub.50,2 of the second filler (d.sub.50,1>d.sub.50,2). The ratio d.sub.50,1 to d.sub.50,2 (d.sub.50,1:d.sub.50,2) is in the range of 8:1 to 100:1. The filler mixture is useful, and a reaction resin system can contain the hardener composition.

The present invention primarily relates to the use of a mixture capable of biocementation as a means of preventing or reducing plant growth, preferably weed growth. The invention also relates to a method for preventing or reducing plant growth, preferably weed growth, on/in a substrate.

The present invention primarily relates to the use of a mixture capable of biocementation as a means of preventing or reducing plant growth, preferably weed growth. The invention also relates to a method for preventing or reducing plant growth, preferably weed growth, on/in a substrate.

The present invention is related to water-swellable polymer particles which contain a hydrophilic base polymer (B) and a hydrophobic polymer (P). It is also related to a process for producing the water-swellable polymer particles, an article containing the water-swellable polymer particles and the use of the water-swellable polymer particles.

Aqueous polymer dispersions are produced by radically initiated emulsion polymerization of ethylenically unsaturated monomers in the presence of protective colloids and/or emulsifiers in a continuously operated tubular reactor, characterized in that the direction of flow of the reactor contents is reversed along the longitudinal axis of the reactor over the course of polymerization.

A non-polar reaction resin mixture can be used to improve the adhesion of a mortar composition based on radically polymerizable compounds, in particular based on urethane (meth)acrylates, on the surface of semi-cleaned and/or damp boreholes in mineral substrates. The use of a non-polar reaction resin mixture in the corresponding mortar composition reduced the sensitivity thereof to dampness and inadequate cleaning conditions, so that mortar compositions are obtained overall which are characterized by improved robustness against external influences.

A non-polar reaction resin mixture can be used to improve the adhesion of a mortar composition based on radically polymerizable compounds, in particular based on urethane (meth)acrylates, on the surface of semi-cleaned and/or damp boreholes in mineral substrates. The use of a non-polar reaction resin mixture in the corresponding mortar composition reduced the sensitivity thereof to dampness and inadequate cleaning conditions, so that mortar compositions are obtained overall which are characterized by improved robustness against external influences.