Patent Application
20200165367
The invention relates to an aqueous composition comprising a copolymer obtained by a particular polymerisation reaction implementing an anionic monomer comprising a polymerisable olefinic unsaturation and a carboxylic acid group and a monomer of formula (I):
The invention also relates to this copolymer per se as well as to a method for preparing it and to the use thereof as a superplasticising agent.
The composition according to the invention is advantageously used in the technical field of mortars, concrete, plasters or other compositions based on hydraulic compounds or binders, especially on cement and plaster. Such compositions can be advantageously implemented in the fields of construction and public works, or in the exploitation of hydrocarbons.
Dispersant compounds of hydraulic binders are typically used for their ability to change the rheology of the medium in which they are present, in particular for their ability to control the workability of this medium.
Workability is usually defined as the property of a composition comprising a hydraulic binder, in particular slag or a cement or mortar slurry, or concrete, for example ready-to-use concrete or precasting concrete, to remain workable for as long as possible. Advantageously, controlling workability makes it possible to transport or move the aqueous composition comprising the hydraulic binder, for example during transport or movement from one tank to another tank. Workability also makes it possible to control the conditions in which such an aqueous composition is stored. It also makes it possible to pump this composition, or to pump it easily. Controlling the workability of such a composition thus makes it possible to improve the conditions of use, in particular to increase its usage time under satisfactory or effective conditions. In general, the workability of an aqueous composition comprising a hydraulic binder can be assessed by measuring the slump time of the hydraulic binder. In particular, the hydraulic binder or superplasticising agent should make it possible to obtain a composition having a stable, controlled viscosity and, preferably, a viscosity that is stable over a long period. Preferably, improving the workability of aqueous hydraulic compositions comprising a hydraulic binder should be possible for compositions comprising a small amount of water.
Thus, an important aspect of the invention lies in the provision of an aqueous composition comprising a hydraulic binder having improved workability time. Controlling workability should not lead to an alteration of other properties, in particular of mechanical properties, especially when the composition is newly formed.
The workability of aqueous compositions comprising a hydraulic binder can be assessed by measuring the slump, for example in accordance with standard EN 12350-2. Indeed, slump and workability are proportional.
Slump retention is another property to be controlled in aqueous compositions comprising a hydraulic binder.
These properties are particularly sought for certain applications, for example when filling formwork with an aqueous composition comprising a hydraulic binder.
Another aspect of the invention relates to obtaining an aqueous composition comprising a hydraulic binder that makes it possible to limit or reduce shrinkage when drying. Improving the properties of aqueous compositions comprising a hydraulic binder should be achieved without altering the setting of the composition, in particular without delaying the setting.
Aqueous compositions comprising a hydraulic binder should also have the lowest possible weight ratio of water/hydraulic binder, generally water/cement or W/C, without undergoing any alteration of their properties.
One effect that is also sought in aqueous compositions comprising a hydraulic binder is to make it possible to control the amount of air locked in the material resulting from the setting of the composition, which thus makes it possible to avoid or reduce the use of anti-foaming agents in the hydraulic composition.
In general, aqueous compositions comprising a hydraulic binder should make it possible to improve the mechanical properties of the materials obtained, in particular their mechanical properties when newly formed; these properties can be assessed by measuring the change in the compression strength over time.
In addition, the compounds used in the preparation of aqueous compositions comprising a hydraulic binder should be used in smaller amounts.
They should also be highly or fully compatible with the other components of the aqueous compositions comprising a hydraulic binder, in particular by being miscible in all proportions with these other components in order to avoid or limit the risk of segregation of the components of the aqueous composition comprising a hydraulic binder.
Increasing the retention time of the properties of the aqueous compositions comprising a hydraulic binder must also be sought.
There are known dispersant compounds or superplasticising agents that can be used in aqueous compositions comprising a hydraulic binder. However, these compounds do not make it possible to provide a solution to the problems encountered. In particular, these compounds do not make it possible to maintain a good initial slump level of the aqueous compositions comprising a hydraulic binder in which they are incorporated, while maintaining their workability and without altering their mechanical properties or triggering segregation phenomena.
Application US 2014 0051801 describes a maleic acid-based comb polymer without specifying its polymolecularity index. Application US 2010 0168282 describes a hydraulic composition comprising a terpolymer obtained by polymerisation in particular of a monomer with quaternary ammonium groups with a monomer with ester functions, in the presence of ammonium persulphate but with no compound comprising phosphorus in the 1 oxidation state.
There is therefore a need for dispersant compounds or superplasticising agents for aqueous compositions comprising a hydraulic binder that make it possible to provide a solution to all or part of the compounds in the prior art.
The invention makes it possible to provide a solution to all or part of the problems encountered with polymeric compositions in the prior art. In particular, the invention makes it possible to obtain copolymers using a particularly effective method of preparation, for example with regard to controlling the temperature of the polymerisation reaction. It is particularly essential to be able to use preparation methods that make it possible to avoid the need for maintaining a low temperature of the reaction medium implemented during the polymerisation reactions known in the prior art.
Moreover, it is also essential to be able to use preparation methods that make it possible to polymerise unsaturated monomers having different molecular masses MW, for example molecular masses MW ranging from 800 to 5,000 g/mol measured by SEC, in the presence of comonomers comprising vinyl groups.
Likewise, it is essential to be able to implement polymerisation reactions that make it possible to copolymerise monomers having reactivities that limit or impede their polymerisation when implementing the methods in the prior art.
It is also essential to be able to control these polymerisation reactions, in particular to control the proportions of the polymerised comonomers with respect to the proportions of said comonomers introduced during the reaction. The copolymers prepared can thus comprise comonomer residues in proportions that are identical or similar to the proportions of the monomers used.
Thus, the invention provides an aqueous composition comprising at least one copolymer the polymolecularity index PI of which is less than 3, obtained by at least one radical polymerisation reaction in water and at a temperature ranging from 10 to 90° C.,
wherein:
The conditions for preparing the composition according to the invention are particularly advantageous. Indeed, these conditions for preparing the composition according to the invention make it possible to reduce or avoid the formation of homopolymers of monomer (a). Thus, preferably, the composition according to the invention does not comprise any homopolymers of monomer (a) with respect to the amount by dry weight of copolymer. Also preferably, the composition according to the invention comprises a reduced, small or very small amount of homopolymers of monomer (a) with respect to the amount by dry weight of copolymer. Likewise, the invention makes it possible to avoid or greatly restrict the formation of different copolymers of monomer (a).
According to the invention, the absence or presence of a reduced, small or very small amount of homopolymer of monomer (a) in the composition according to the invention makes it possible to avoid or limit the risk of inhibiting crystallisation of the concrete when the composition according to the invention is used for its plasticising properties in a concrete formulation. Generally, a homopolymer of monomer (a) has properties that disperse mineral matter particles and can thus disrupt or inhibit crystallisation in a concrete formulation. The properties of the concrete formulation or of the final material prepared using the concrete formulation can thus be changed or altered.
Particularly advantageously and particularly effectively, the invention makes it possible to prepare a copolymer from monomers (a) and (b) while controlling the polymerisation reaction of monomers (a) and (b). The invention thus makes it possible to obtain an aqueous composition comprising a very small amount of residual monomer (a) with respect to the amount by dry weight of copolymer. Preferably, the aqueous composition according to the invention comprises less than 2,000 ppm by weight or less than 1,500 ppm by weight of residual monomer (a) with respect to the amount by dry weight of copolymer. More preferably, the aqueous composition according to the invention comprises less than 1,000 ppm by weight or less than 500 ppm by weight of residual monomer (a) with respect to the amount by dry weight of copolymer. In particular, the aqueous composition according to the invention can comprise less than 200 ppm by weight or less than 100 ppm by weight of residual monomer (a) with respect to the amount by dry weight of copolymer.
The aqueous composition according to the invention comprises at least one copolymer the polymolecularity index PI of which is less than 3. Preferably according to the invention, the polymolecularity index PI ranges from 1.5 to 3, more preferentially from 1.5 to 2.8, much more preferentially from 1.5 to 2.5.
The copolymer of the aqueous composition according to the invention is obtained by at least one radical polymerisation reaction in water and at a temperature ranging from 10 to 90° C., preferably ranging from 30 to 85° C., more preferentially at a temperature ranging from 40 to 75° C. or from 50 to 70° C. More preferably, only one radical polymerisation reaction is implemented.
Preparing the aqueous composition according to the invention implements a radical polymerisation reaction that is carried out in water in the presence of at least one compound (i) comprising phosphorus in the I oxidation state. More preferably according to the invention, the polymerisation reaction implements a mineral compound (i). More preferably according to the invention, the polymerisation reaction implements a compound (i) chosen among hypophosphorous acid (H3PO2), a derivative of hypophosphorous acid (H3PO2). Even more preferably according to the invention, the polymerisation reaction implements a compound (i) comprising at least one hypophosphite ion (H2PO2—), more preferentially a compound chosen among sodium hypophosphite (H2PO2Na), potassium hypophosphite (H2PO2K), calcium hypophosphite ([H2PO2]2Ca) and mixtures thereof. Sodium hypophosphite (H2PO2Na) is particularly preferred.
Preparing the aqueous composition according to the invention also implements at least one radical-generating compound (ii) which is particular. It is preferentially chosen among hydrogen peroxide, ammonium persulphate, sodium persulphate, potassium persulphate, mixtures thereof or their associations with sodium bisulphite or potassium bisulphite or with an ion chosen among FeII, FeIII, CuI, CuII. According to the invention, the FeII, FeIII, CuI or CuII ions can be implemented by means of at least one compound chosen among iron sulphate, hydrated iron sulphate, iron sulphate hemihydrate, iron sulphate heptahydrate, iron carbonate, hydrated iron carbonate, iron carbonate hemihydrate, iron chloride, copper carbonate, hydrated copper carbonate, copper carbonate hemihydrate, copper acetate, copper sulphate, copper sulphate pentahydrate, copper hydroxide, and copper halide.
According to the invention, the particular radical-generating compound is more preferentially chosen among hydrogen peroxide, ammonium persulphate, sodium persulphate, potassium persulphate, in particular sodium persulphate.
In addition to compounds (i) and (ii), the polymerisation reaction according to the invention can also implement at least one compound (iii) of formula (II):
Preferably according to the invention, this compound (iii) is a compound of formula (II) in which R represents a C1-C3-alkyl group, preferably a methyl group. The preferred compound of formula (II) according to the invention is disodic dipropionate trithiocarbonate (DPTTC—CAS No. 86470-33-2).
Preferably according to the invention, compound (iii) is implemented in an amount by weight ranging from 0.05 to 5% by weight, with respect to the amount of monomers.
Also preferably according to the invention, the polymerisation reaction implements compound (iii) of formula (II) in an amount of from 0.05 to 4% by weight, from 0.05 to 3% by weight, from 0.05 to 2% by weight, from 0.5 to 4% by weight, from 0.5 to 3% by weight, from 0.5 to 2% by weight, from 1 to 4% by weight, from 1 to 3% by weight, from 1 to 2% by weight with respect to the amount of monomers.
When preparing the copolymer according to the invention, the amounts of monomers (a) and (b) implemented can vary greatly. Preferably, the polymerisation reaction implements:
Also preferably, the polymerisation reaction implements:
Also preferably, the polymerisation reaction implements:
Also preferably, the polymerisation reaction implements:
Also preferably, the polymerisation reaction implements:
The invention comprises the implementation of a radical polymerisation reaction in water of at least one anionic monomer (a) comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group or one of its salts. Preferably, the composition according to the invention comprises a copolymer prepared by a polymerisation reaction implementing an anionic monomer (a) comprising a polymerisable olefinic unsaturation and a carboxylic acid group or one of its salts. More preferably, the monomer (a) implemented is chosen among acrylic acid, methacrylic acid, itaconic acid, maleic acid, an acrylic acid salt, a methacrylic acid salt, an itaconic acid salt, a maleic acid salt and mixtures thereof. Much more preferably, the monomer (a) implemented is chosen among acrylic acid, methacrylic acid, an acrylic acid salt, a methacrylic acid salt and mixtures thereof, more particularly acrylic acid or an acrylic acid salt, in particular a sodium salt of acrylic acid.
During the radical polymerisation reaction in water, the invention also comprises the implementation of at least one monomer (b) of formula (I).
Preferably, the compound (b) of formula (I) is a compound wherein:
Even more preferably, the compound (b) is a compound of formula (I) wherein x represents an integer or decimal comprised in a range from 10 to 150 or from 30 to 120, y+z represents an integer or decimal comprised in a range from 10 to 135, x is strictly greater than y+z and the sum of x+y+z is comprised in a range from 10 to 150. Also more preferably, the compound (b) is a compound of formula (I) wherein x represents an integer or decimal comprised in a range from 20 to 130 or from 30 to 120, and y and z represent 0.
Also more preferably, the compound (b) is a compound of formula (I) wherein x represents an integer or decimal comprised in a range from 15 to 80 and y+z represents an integer or decimal comprised in a range from 10 to 65, preferably a compound of formula (I) wherein x represents an integer or decimal comprised in a range from 30 to 65 and y+z represents an integer or decimal comprised in a range from 15 to 40, in particular a compound of formula (I) wherein x represents an integer or decimal comprised in a range from 40 to 60 and y+z represents an integer or decimal comprised in a range from 20 to 30, for example a compound of formula (I) wherein x represents 50 and y represents 25.
Also more preferably, the monomer (b) is a compound of formula (I) wherein x is strictly greater than y+z.
According to the invention, a preferred compound (b) is chosen among the compounds of formulae (Ia), (Ib), (Ic) and (Id):
wherein:
According to the invention, a more preferred compound (b) is a compound (b1) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b2) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b3) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b4) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b5) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b6) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b7) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b8) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b9) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b10) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b11) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
According to the invention, a more preferred compound (b) is a compound (b12) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic), and (Id), wherein:
More preferably, the monomers (b) can be chosen among the monomers:
The aqueous composition according to the invention can thus also comprise at least one copolymer the polymolecularity index PI of which is less than 3, obtained by at least one radical polymerisation reaction in water and at a temperature ranging from 10 to 90° C. of at least one monomer (a) and two different monomers (b).
Preferably, the monomers (b) can be chosen among the compounds of formulae (I), (Ia), (Ib), (Ic) and (Id). Also preferably, they can be chosen among the monomers (b1) to (b12) or among the monomers (b1b), (b1d), (b3a), (b3b), (b3c), (b4a), (b5b), (b5d), (b7a), (b7b), (b7c), (b7d), (b8a), (b9b), (b9d), (b11a), (b11b), (b11c), (b12a).
The aqueous composition according to the invention comprises at least one copolymer obtained by means of at least one radical polymerisation reaction in water of at least one monomer (a) and at least one monomer (b), chosen among the compounds of formulae (I), (Ia), (Ib), (Ic) and (Id). The polymerisation reaction can also implement one or several other monomers.
The polymerisation reaction then also implements at least one other monomer chosen among:
Q1-(L1)m-(L2)n-Q2 (III)
wherein:
Advantageously, the aqueous composition according to the invention comprises at least one copolymer obtained by at least one radical polymerisation reaction in water carried out in the absence of maleic acid or in the absence of maleic anhydride.
The invention provides an aqueous composition comprising at least one copolymer obtained by at least one radical polymerisation reaction in water of at least one anionic monomer (a) comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group or one of its salts and of at least one monomer (b) chosen among the compounds of formulae (I), (Ia), (Ib), (Ic) and (Id).
The invention also relates to such a copolymer per se, in particular such a copolymer obtained from an aqueous composition according to the invention then separation of the copolymer according to the invention, in particular separation of the water from the aqueous composition according to the invention.
The invention thus provides a copolymer the polymolecularity index PI of which is less than 3, obtained by at least one radical polymerisation reaction in water and at a temperature ranging from 10 to 90° C.,
Particularly advantageously, the copolymer according to the invention comprises:
Preferably, the copolymer according to the invention comprises:
Also preferably, the copolymer according to the invention comprises:
Also preferably, the copolymer according to the invention comprises:
Also preferably, the copolymer according to the invention comprises:
The copolymer according to the invention can also be characterised by its weight-average molecular mass (MW). Preferably, it has a weight-average molecular mass ranging from 8,000 g/mol to 600,000 g/mol or from 10,000 g/mol to 500,000 g/mol or from
12,000 g/mol to 200,000 g/mol. More preferably, it has a weight-average molecular mass ranging from 15,000 g/mol to 150,000 g/mol or from 15,000 g/mol to 90,000 g/mol or from 15,000 g/mol to 90,000 g/mol or from 25,000 g/mol to 75,000 g/mol.
According to the invention, the molecular weight and polymolecularity index of the copolymers is determined by Steric Exclusion Chromatography (SEC). This technique implements a Waters liquid chromatography apparatus equipped with a detector. This detector is a Waters refractive index detector. This liquid chromatography apparatus is equipped with a steric exclusion column in order to separate the various molecular weights of the copolymers studied. The liquid elution phase is an aqueous phase adjusted to pH 9.00 using 1N sodium hydroxide containing 0.05 M NaHCO3, 0.1 M NaNO3, 0.02 M triethanolamine and 0.03% NaN3.
According to a first step, the copolymer solution is diluted to 0.9% by dry weight in the solubilisation solvent of the SEC, which corresponds to the liquid elution phase of the SEC to which 0.04% of dimethyl formamide is added, which acts as a flow rate marker or internal standard. Then it is filtered using a 0.2 μm filter. Then 100 μL are injected into the chromatograph (eluent: an aqueous phase adjusted to pH 9.00 using 1N sodium hydroxide containing 0.05 M of NaHCO3, 0.1 M of NaNO3, 0.02 M of triethanolamine and 0.03% of NaN3).
The liquid chromatography apparatus has an isocratic pump (Waters 515) the flow rate of which is set to 0.8 mL/min. The chromatography apparatus also comprises an oven which itself comprises the following system of columns in series: a Waters Ultrahydrogel Guard precolumn 6 cm long and 40 mm in inner diameter, and a Waters Ultrahydrogel linear column 30 cm long and 7.8 mm in inner diameter. The detection system is comprised of a Waters 410 RI refractive index detector. The oven is heated to 60° C. and the refractometer is heated to 45° C.
Molecular mass is assessed by detection of the dynamic light scattering using a Viscotek 270 dual detector to determine the molecular mass based on the hydrodynamic volume of the copolymer.
The particular, advantageous or preferred characteristics of the aqueous composition according to the invention define copolymers according to the invention which are also particular, advantageous or preferred.
The aqueous composition and the copolymer according to the invention have properties that are particularly advantageous in many technical fields. Thus, according to the technical field in which these properties are implemented, the aqueous composition or the copolymer according to the invention can have different forms. They can in particular be implemented in various formulations.
The invention thus provides a formulation (F1) comprising:
The invention also provides a formulation (F2) comprising:
Preferably, formulations (F1) and (F2) according to the invention comprise:
More preferably, formulations (F1) and (F2) according to the invention comprise:
Also more preferably, formulations (F1) and (F2) according to the invention comprise:
Also more preferably, formulations (F1) and (F2) according to the invention comprise:
Also preferably, formulations (F1) and (F2) according to the invention comprise water in an amount by weight, with respect to the amount by weight of the hydraulic binder, of less than 0.7, less than 0.65 or less than 0.6, preferably less than 0.5 or less than 0.4, or less than 0.3 or less than 0.2. The amount by weight of water with respect to the amount by weight of hydraulic binder in formulations (F1) and (F2) preferably ranges from 0.2 to 0.65 or from 0.2 to 0.6 or from 0.2 to 0.5 or from 0.3 to 0.65 or from 0.3 to 0.6 or from 0.3 to 0.5.
According to the invention, the hydraulic binder or hydrolith can be chosen among cement, mortar, plaster, slurry or concrete.
The cement can be chosen among Portland cement, white Portland cement, artificial cement, blast furnace cement, high strength cement, aluminate cement, quick-setting cement, magnesium phosphate cement, cement based on incineration products, fly ash cement and mixtures thereof.
Other hydraulic binders can be chosen among latent hydraulic binders, pozzolanic binders, ash, slag, clinker.
The plaster can be chosen among gypsum, calcium sulphate dihydrate, calcium sulphate, calcium sulphate hemihydrate, calcium sulphate anhydride and mixtures thereof.
The aggregate can be chosen among sand, coarse aggregate, gravel, crushed stone, slag, recycled aggregate.
Generally, according to their particle size, granulates are classified in several known categories as such by the person skilled in the art, for example according to French standard XP P 18-540. According to this standard, which notably defines the d and D values, the granulate families comprise:
Examples of fillers are silica fume or siliceous additions, or calcareous additions such as calcium carbonate.
According to the invention, the admixture in formulations (F1) or (F2) can be chosen among an anti-foaming agent, a plasticising or superplasticising agent, a workability-enhancing agent, a slump-reducing agent, an agent for reducing trapped air, a colouring agent, a pigment, a water-reducing agent, a surface retardant, a hygroscopicity control agent, an anti-corrosion agent, an anti-shrink agent, a silico-alkaline-reaction-inhibiting agent, a waterproofing agent, a foaming agent.
The particular properties of the aqueous composition according to the invention or of the copolymer according to the invention make it possible to use them in many technical fields, in particular for their rheology regulation or control properties.
Thus, the invention provides a method for changing the rheology of a hydraulic formulation comprising the addition of at least one aqueous composition according to the invention or of at least one copolymer according to the invention in the hydraulic formulation comprising water and a hydraulic binder.
The properties of the composition according to the invention and of the copolymer are particularly useful in the field of hydraulic formulations.
Thus, the invention provides a method for controlling the workability of a hydraulic formulation comprising the addition of at least one aqueous composition according to the invention or of at least one copolymer according to the invention in a hydraulic formulation. Particularly advantageously, the invention provides a method for controlling workability wherein the workability of the hydraulic formulation is kept constant for at least 1 hour, preferably for at least 2 hours, more preferentially for at least 3 hours, even more preferentially for at least 3.5 hours or at least 4 hours.
The invention also provides a method for reducing the setting time of a hydraulic formulation comprising the addition of at least one aqueous composition according to the invention or of at least one copolymer according to the invention in a hydraulic formulation comprising water and a hydraulic binder.
In methods for controlling the workability of a hydraulic formulation or reducing the setting time of a hydraulic formulation according to the invention, the hydraulic formulation is preferably chosen from a hydraulic formulation (F1) and a hydraulic formulation (F2).
The particular, advantageous or preferred characteristics of the hydraulic formulations (F1) and (F2) according to the invention define the methods for controlling the workability of a hydraulic formulation or for reducing the setting time of a hydraulic formulation according to the invention which are also particular, advantageous or preferred.
The following examples illustrate the various aspects of the invention.
Water (80 g), a 60% by mass solution of monomer (b7b) with a molecular mass of 2,400 g/mol in water (380.37 g) and sodium hypophosphite monohydrate (1.02 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (41.95 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (9.18 g), and a mixture of water (60 g) and sodium persulphate (4.09 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass (44.5 g). The aqueous polymeric solution comprises less than 1 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P1) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (b7b) is obtained. It has a molecular mass MW of 33,300 g/mol and a polymolecularity index PI of 1.9.
Water (150 g), iron sulphate heptahydrate (0.214 g), copper sulphate pentahydrate (0.030 g) and a 60% by mass solution of monomer (b7b) with a molecular mass of 2,400 g/mol in water (456.87 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (50.4 g), a mixture of water (65 g) and sodium hypophosphite monohydrate (25.6 g), and a mixture of water (50 g) and a 35% by mass solution of hydrogen peroxide in an aqueous solution (20.5 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass (7.9 g). The aqueous polymeric solution comprises less than 1 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P2) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (b7b) is obtained. It has a molecular mass MW of 26,700 g/mol and a polymolecularity index PI of 2.0.
Water (100 g), a 60% by mass solution of monomer (b7b) with a molecular mass of 2,400 g/mol in water (380.37 g) and sodium hypophosphite monohydrate (2.04 g) are placed in a stirred reactor. The reactor is heated to 55±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (41.95 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (18.36 g) and a mixture of water (60 g) and sodium persulphate (8.17 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 55±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass (44.3 g). The aqueous polymeric solution comprises less than 115 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P3) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (b7b) is obtained. It has a molecular mass MW of 16,700 g/mol and a polymolecularity index PI of 2.0.
Water (10 g), a 60% by mass solution of monomer (b7b) with a molecular mass of 2,400 g/mol in water (684.67 g) and sodium hypophosphite monohydrate (1.84 g) are placed in a stirred reactor. The reactor is heated to 75±2° C.
Then, for 2 hours, a mixture of water (10 g) and acrylic acid (75.51 g), a mixture of water (90 g) and sodium hypophosphite monohydrate (16.52 g) and a mixture of water (70 g) and sodium persulphate (7.36 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 75±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass (81.5 g). The aqueous polymeric solution comprises less than 2 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P4) comprising 15.5% by weight of acrylic acid and 84.5% by weight of monomer (b7b) is obtained. It has a molecular mass MW of 25,900 g/mol and a polymolecularity index PI of 1.8.
Water (157 g), a monomer (b7d) with a molecular mass of 2,400 g/mol (201 g) and sodium hypophosphite monohydrate (0.57 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (21.23 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (5.3 g) and a mixture of water (40 g) and sodium persulphate (2.28 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass until pH 7 is reached. The aqueous polymeric solution comprises less than 10 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P5) with a weight-average molecular mass of 38,430 g/mol and a polymolecularity index PI of 1.9 is obtained.
Water (40 g), a 60% solution of monomer (b3b) in which x=42 and y+z=15.5, with a molecular mass of 3,000 g/mol (368 g) and sodium hypophosphite monohydrate (0.63 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (23.34 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (5.64 g) and a mixture of water (40 g) and sodium persulphate (2.51 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass until pH 7.1 is reached. The aqueous polymeric solution comprises 880 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P6) with a weight-average molecular mass of 49,890 g/mol and a polymolecularity index PI of 1.2 is obtained.
Water (40 g), a 60% solution of monomer (b3b) in which x=42 and y+z=15.5, with a molecular mass of 3,000 g/mol (478 g) and sodium hypophosphite monohydrate (0.63 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (20.97 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (5.64 g) and a mixture of water (40 g) and sodium persulphate (2.51 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass until pH 7.4 is reached. The aqueous polymeric solution comprises 850 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P7) with a weight-average molecular mass of 44,880 g/mol and a polymolecularity index PI of 2 is obtained.
Water (40 g), a 60% solution of monomer (b3b) in which x=52 and y+z=11, with a molecular mass of 3,000 g/mol (368 g) and sodium hypophosphite monohydrate (0.63 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (23.34 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (5.64 g) and a mixture of water (40 g) and sodium persulphate (2.51 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass until pH 7.6 is reached. The aqueous polymeric solution comprises 1,670 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P8) with a weight-average molecular mass of 31,330 g/mol and a polymolecularity index PI of 1.2 is obtained.
Water (157 g), a monomer (b7d) with a molecular mass of 2,400 g/mol (220 g) and sodium hypophosphite monohydrate (0.63 g) are placed in a stirred reactor.
The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g), acrylic acid (18.67 g) and methacrylic acid (4.67 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (5.64 g) and a mixture of water (40 g) and sodium persulphate (2.28 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass until pH 7.1 is reached. The aqueous polymeric solution comprises less than 50 ppm of residual dry methacrylic acid and 2 ppm of dry methacrylic acid with respect to the total amount of dry copolymer.
A copolymer (P9) with a weight-average molecular mass of 38,585 g/mol and a polymolecularity index PI of 1.4 is obtained.
Water (80 g), a monomer (b3b) in which x=42 and y+z=15.5, with a molecular mass of 3,000 g/mol (45.64 g), a 60% solution of monomer (b7d) with a molecular mass of 2,400 g/mol (274 g) and sodium hypophosphite monohydrate (1.02 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g), of acrylic acid (42 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (9.2 g) and a mixture of water (40 g) and sodium persulphate (4.09 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass until pH 7.2 is reached. The aqueous polymeric solution comprises less than 2 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (PI) with a weight-average molecular mass of 51,720 g/mol and a polymolecularity index PI of 1.8 is obtained.
Water (320 g), a monomer (b7d) with a molecular mass of 3,500 g/mol (294.8 g) and sodium hypophosphite monohydrate (1.02 g) are placed in a stirred reactor. The reactor is heated to 65±2° C.
Then, for 2 hours, a mixture of water (50 g) and acrylic acid (41.95 g), a mixture of water (50 g) and sodium hypophosphite monohydrate (9.18 g) and a mixture of water (40 g) and sodium persulphate (4.09 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass until pH 7 is reached. The aqueous polymeric solution comprises less than 10 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
A copolymer (P11) with a weight-average molecular mass of 36,610 g/mol and a polymolecularity index Pr of 1.7 is obtained.
Water (50 g), iron sulphate heptahydrate (0.11 g), a 60% by mass solution of monomer (b7b) with a molecular mass of 2,400 g/mol in water (264.56 g) and DMDO (1,8-dimercapto-3,6-dioxaoctane) (0.62 g) are placed in a stirred reactor. The reactor is heated to 37±2° C. Hydrogen peroxide is added in an aqueous solution at 35% by mass (5.6 g).
Then, for 1 hour and 15 minutes, a mixture of water (30 g) and acrylic acid (32.49 g), a mixture of water (25 g), a 60% by mass solution of monomer (b7b) with a molecular mass of 2,400 g/mol in water (32.7 g) and DMDO (4.93 g), along with a mixture of water
(55 g) and a 40% by mass solution of sodium bisulphite in water (5.64 g), are simultaneously injected into the reactor, with this latter mixture injected in 1 hour and 40 minutes.
The reactor is kept at a temperature of 37±2° C. for 1 hour and 30 minutes.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass (36.6 g). The aqueous polymeric solution comprises more than 12,000 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer. Moreover, nearly 20% by weight of monomer (b7b) did not react.
Water (400 g) is placed in a stirred reactor and heated to 65±2° C.
Then, for 3 hours, a mixture of water (40 g), acrylic acid (49.35 g) and monomer (b3a) with a molecular mass of 3,000 g/mol (312.81 g), a mixture of water (30 g), DMDO (1.80 g) and monomer (b12) with a molecular mass of 3,000 g/mol (50.00 g), along with a mixture of water (84.9 g) and ammonium persulphate (1.51 g) are simultaneously injected into the reactor.
The reactor is kept at a temperature of 65±2° C. for 1 hour and 30 minutes.
The product is cooled and then partially neutralised by adding an aqueous solution of sodium hydroxide at 50% by mass (4.1 g). The aqueous polymeric solution comprises more than 4,930 ppm of residual dry acrylic acid with respect to the total amount of dry copolymer.
Mortar formulations, the compositions of which are shown in Table 1, are prepared according to the following procedure:
Similarly, a comparative formulation (CF) of mortar is prepared comprising no copolymer.
The water-reducing properties of the copolymers according to the invention are assessed using the mortar formulations.
The TO workability of the mortars formulated with the copolymers according to the invention was assessed by measuring the slump flow in accordance with standard EN 12350-2 adapted to mortar (Abrams mini-cone test).
To perform the slump flow test, the cone filled with formulated mortar is lifted perpendicular to a horizontal plate while rotating it one-quarter turn. The slump is measured with a ruler after 5 minutes across two 90° diameters. The result of the slump test is the average of the 2 values to ±1 mm.
The tests are conducted at 20° C. The admixture content is determined such that a target slump of 220 mm±5 mm can be reached. The content is expressed in % by dry weight with respect to the weight of the hydraulic binder or the mixture of hydraulic binders. The results are shown in table 1.
Implementing the copolymers according to the invention makes it possible to reduce the amount of water in the hydraulic formulation by 25% while maintaining an initial slump level (workability) similar to that of the comparative formulation comprising no copolymer.
The copolymers according to the invention can therefore be qualified as highly water-reducing agents according to French standard ADJUVANT NF EN 934-2. Indeed, they make it possible to reduce the water in the admixed mortar by at least 12% with respect to the control mortar.
Implementing the copolymers according to the invention would make it possible to obtain similar results in admixed concrete by reducing the amount of water by at least 12% with respect to a control concrete comprising no copolymer according to the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1757235 | Jul 2017 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2018/051902 | 7/25/2018 | WO | 00 |
