Methods for obtaining biologically derived N-vinylformamide

Abstract

The present invention relates to a process for obtaining N-vinylformamide, comprising the reaction between acetaldehyde and formamide, one of the two, preferably both of which are at least partially renewable and non-fossil.The present invention further relates to bio-based N-vinylformamide monomers, bio-based polymers incorporating at least said monomers, and the use of said polymers in various technical fields.

Description

[Technical field]

[0001] The present invention relates to a method for obtaining bio-based N-vinylformamide, comprising the reaction between acetaldehyde and formamide, one of the two, preferably both of which are at least partially renewable and non-fossil.The present invention relates to a bio-based N-vinylformamide monomer and to a bio-based polymer obtained from at least one bio-based N-vinylformamide monomer according to the present invention.Finally, the present invention relates to the use of the bio-based polymer of the present invention in various technical fields. [Background technology]

[0002] Ethylenically unsaturated monomers such as N-vinylformamide are widely used in the preparation of water-soluble polymers.

[0003] N-vinylformamide (NVF) can be obtained according to the following reaction scheme:

[0004] [ka]

[0005] There are several variants depending on the HX protecting agent used. NVF is generally synthesized by the so-called "alkoxy" process, where the protecting agent is an alcohol, more preferably methanol. The synthesis is carried out in two steps starting from hydroxyethylformamide, which is obtained from acetaldehyde and formamide. Hydroxyethylformamide is converted to methoxyethylformamide by reaction with methanol and a catalyst. Methoxyethylformamide is then pyrolyzed at high temperature to give N-vinylformamide.

[0006] Acetaldehyde is a feedstock derived from the oxidation of ethylene, as described in the Wacker process. Ethylene is a fossil olefin currently produced by steam cracking of naphtha, itself derived from crude oil refining. More recently, with the advent of shale gas production, various ethane dehydrogenation processes have been described to produce ethylene.

[0007] Fossil ethylene contains various impurities that either remain or are converted by the Wacker process. Furthermore, the presence of oxygen in the Wacker process tends to oxidize acetaldehyde to acetic acid.

[0008] Formamide is obtained from the reaction of formic acid with ammonia, which is fossil-based and is obtained from the reaction between ethane and oxygen, as described in document US 3,056,833.

[0009] Document US 4,567,300 describes the formation of hydroxyethylformamide in the presence of acetaldehyde and formamide.To counteract the acidic presence of fossil acetaldehyde, it is described that a base, in this case potassium carbonate, is added to allow good conversion of reactants and obtain good quality hydroxyethylformamide.

[0010] Other variants for obtaining N-vinylformamide, for example the so-called "prussic acid" process, are described in particular in document US 3,822,306. In this case, the protecting agent is prussic acid, which reacts with acetaldehyde. The yield is limited to 75% and contains the highly toxic compound prussic acid. N-vinylformamide can also be obtained according to another variant known as "bisethyleneformamide", described for example in document US 4,906,777.

[0011] In either case, the three carbons of N-vinylformamide are derived from acetaldehyde and formamide.

[0012] To counter the use of raw materials with high impurities that lead to poor quality N-vinylformamide, a strategy for purifying N-vinylformamide is described.

[0013] In the document US 4,818,505, an ultra-high vacuum (0.5 mbar or 1 bar = 1000 psi) is used to separate unreacted formamide and N-vinylformamide from the previous step. 5 A fractional distillation process is described in a column operated at 1000 rpm (1000 rpm, ...

[0014] Document WO 2018 / 108608 A1 describes (a) 9.49 to 98 mol % of the formula [CH 2 -CR 1 ((C=O)-NR 2 -A-SO 2 -O - Q + %), wherein at least 10 wt.% of these units of formula (1) contain a bio-based carbon content of 28 wt.% to 100 wt.%, (b) 0.01 mol% to 5 mol% of crosslinked or branched units, (c) 0.01 mol% to 88.52 mol% of repeating neutral structural units, and (d) 1.98 mol% to 20 mol% of repeating anionic structural units. Document WO 2018 / 108608 A1 does not teach polymers containing bio-based N-vinylformamide.

[0015] Document US2018 / 057445 relates to a method for producing N-vinylcarboxylic acid amides, such as N-vinylformamide and intermediates thereof. The document does not describe the use of compounds of biological origin. [Prior art documents] [Patent documents]

[0016]

Patent Document 1

Patent document 2

Patent document 3

Patent document 4

Patent document 5

Patent document 6

Patent document 7

Patent document 8

Patent document 9

Non-licensed literature

[0017] [Non-licensed document 1] Roessler, N., Valenta, RJ, and Van Cauter, S., "Time-resolved Liquid Scintillation Counting", Liquid Scintillation Counting and Organic Scintillators, Ross, H., Noakes, JE, and Spaulding, JD, Lewis Publishers, Chelsea, MI, 1991, pp. 501~511 [Non-licensed document 2] Allison, CE, Francy, RJ, and Meijer, HAJ, "Reference and Intercomparison Materials for Stable Isotopes of Light Elements", International Atomic Energy Agency, Vienna, Austria, IAEATECHDOC-825, 1995 Summary of the Invention [Problem to be solved by the invention]

[0018] The problem which the present invention proposes to solve is that of proposing new and improved polymers obtained from N-vinylformamide monomers of biological origin. [Means for solving the problem]

[0019] Surprisingly, the Applicant has observed that the use of acetaldehyde and formamide, one of the two, preferably both of which are at least partially renewable and non-fossil, preferably totally renewable, in a process for obtaining N-vinylformamide, makes it possible to substantially improve the quality of the monomer obtained, and thereby its polymerization and the application performance of the polymer obtained.

[0020] The Applicant has observed this improvement in particular when the process is a process for obtaining N-vinylformamide by the "alkoxy" process, in particular when the alcohol used as protecting agent is methanol or isopropanol, preferably methanol.

[0021] Without wishing to be bound by a particular theory, the applicant proposes that the difference in the nature of impurities between fossil acetaldehyde and renewable, non-fossil acetaldehyde and / or between fossil formamide and renewable, non-fossil formamide may be responsible for these unexpected technical effects.

[0022] "A and / or B" is understood to mean according to invention A or B, or according to A and B.

[0023] The present invention first relates to a method for obtaining N-vinylformamide, which comprises the reaction between acetaldehyde and formamide, one of the two, preferably both, being at least partially renewable and non-fossil.

[0024] The present invention further relates to N-vinylformamide having a bio-based carbon content in the range of 5 wt% to 100 wt%, based on the total carbon mass in said N-vinylformamide, wherein the bio-based carbon content is measured according to ASTM D6866-21 Method B.

[0025] The present invention also relates to polymers obtained by polymerization of at least one N-vinylformamide monomer obtained according to the process of the present invention or as described, and to the use of said polymers in various technical fields.

[0026] The present invention makes it possible to achieve the environmental goals inherent in new technological innovations, in which the use of renewable raw materials, in this case acetaldehyde and / or formamide, helps to significantly optimize the conversion process and the quality of the resulting monomers.

[0027] Applicants have observed that the bio-derived nature of formamide allows for better conversion to N-vinylformamide and produces fewer impurities as compared to fossil formamide.

[0028] The applicant has also observed that the conversion percentage of formamide is greater when the acetaldehyde is at least partially of renewable and non-fossil origin, as compared to fossil compounds.

[0029] The applicant has also observed that the use of formamide of partially or totally renewable and non-fossil origin, and acetaldehyde of partially or totally renewable and non-fossil origin, compared to fossil compounds, improves the process for obtaining N-vinylformamide.

[0030] The Applicant has also observed that polymers according to the invention which are obtained partly or wholly from monomers of biological origin are more readily biodegradable than polymers obtained from fossil monomers.

[0031] The applicant has also observed that in addition to better drainage performance, the polymers according to the invention exhibit dry strength performance that is at least equal to or even better than that of polymers obtained from fossil monomers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] In the context of the present invention, the term "renewable and non-fossil" is used to designate the origin of a chemical compound derived from biomass or synthetic gas (syngas), i.e. resulting from one or more chemical transformations carried out on one or more natural and non-fossil raw materials. The term "biogenic" or "bioresourced" can also be used to characterize the renewable and non-fossil origin of a chemical compound. The renewable and non-fossil origin of a compound includes renewable and non-fossil raw materials originating from a circular economy that have been recycled once or multiple times in biomass material recycling processes, such as materials from polymer depolymerization or pyrolysis oil processing.

[0033] According to the present invention, the "at least partially renewable and non-fossil" quality of a compound means a bio-derived carbon content preferably between 5 wt% and 100 wt%, relative to the total carbon mass of said compound.

[0034] In the context of the present invention, method B of the ASTM D6866-21 standard is used to characterize the biogenic nature of chemical compounds and to determine the biogenic carbon content of said compounds, the value being expressed as the mass percentage (wt%) of biogenic carbon relative to the total carbon mass in said compound.

[0035] The ASTM D6866-21 standard is a test method that teaches how to experimentally determine the biogenic carbon content of solid, liquid, and gas samples by radiocarbon analysis.

[0036] This standard primarily uses the Accelerator Mass Spectroscopy (AMS) technique, which is used to naturally measure the radionuclides present in a sample, where atoms are ionized and accelerated to high energies before being separated and counted individually in a Faraday cup. This high-energy separation is so effective at removing isobaric interferences that AMS can measure the abundance of carbon-14 relative to carbon-12 (14C / 12C) by 1.10. -15 It can be measured accurately to an accuracy of .

[0037] Method B of the ASTM D6866-21 standard uses AMS and IRMS (Isotope Ratio Mass Spectrometry). This test method allows for the direct differentiation of modern carbonaceous carbon atoms from fossil carbonaceous carbon atoms. Measurements of the carbon-14 vs. carbon-12 or carbon-14 vs. carbon-13 content of a product are determined against a modern carbonaceous reference material that is accepted by the radiocarbon dating community, such as NIST Standard Reference Material (SRM) 4990C (Oxalic Acid).

[0038] Sample preparation methods are described in standards and are commonly used procedures and therefore do not require special commentary.

[0039] Analysis, interpretation and reporting of results are described below. The isotopic ratio of carbon-14 to carbon-12 content or carbon-14 to carbon-13 content is measured using AMS. The isotopic ratio of carbon-14 to carbon-12 content or carbon-14 to carbon-13 content is determined relative to a standard traceable to the NIST SRM 4990C modern reference standard. The "fraction of modern" (fM) represents the amount of carbon-14 in the test product relative to a modern standard. This is most often referred to as percent modern carbon (pMC), which is the percentage equivalent to fM (e.g., fM1=100 pMC).

[0040] All pMC values ​​derived from radiocarbon analysis must be corrected for isotopic fractionation using a given stable isotope. Corrections should be made using carbon-14 to carbon-13 values ​​determined directly using AMS, when possible. If this is not possible, corrections should be made using delta-13C (δ13C) measured by IRMS, CRDS (cavity ring-down spectroscopy), or other comparable technique capable of providing accuracy to within plus or minus 0.3 parts per thousand.

[0041] "Zero pMC" represents the complete absence of measurable 14C above background signal in the material, and thus indicates a fossil (e.g., petroleum-based) carbon source. A value of 100 pMC indicates an entirely "modern" carbon source. pMC values ​​from 0 to 100 indicate the proportion of carbon derived from fossil sources relative to "modern" sources.

[0042] The pMC may be higher than 100% due to the continuing but decreasing impact of 14C injection into the atmosphere caused by atmospheric nuclear testing programs. The pMC value needs to be adjusted by the Atmospheric Correction Factor (REF) to obtain the actual biogenic content of the sample.

[0043] The correction factor is based on the excess 14C radioactivity in the air at the time of the test. 2Based on measurements, the REF value for 2015 was determined to be 102 pMC. The first version of this standard in 2004 (ASTM D6866-04) referred to a value of 107.5 pMC, while the subsequent version ASTM D6866-10 (2010) referred to a value of 105 pMC. These data points represent a decrease of 0.5 pMC per year. As a result, on January 2nd of each year, the values ​​in Table 1 below will be used as REF values ​​until 2019, reflecting a similar decrease of 0.5 pMC per year. The REF value (pMC) for 2020 and 2021 was determined to be 100.0, based on continuous measurements in the Netherlands (Lutjewad, Groningen) until 2019. References for reporting carbon isotope ratio data are as follows for 14C and 13C, respectively: Roessler, N., Valenta, RJ and van Cauter, S., "Time-resolved Liquid Scintillation Counting", in Liquid Scintillation Counting and Organic Scintillators, Ross, H., Noakes, JE and Spaulding, JD (eds.), Lewis Publishers, Chelsea, MI, 1991, pp. 501-511; Allison, CE, Francy, RJ and Meijer, HAJ, "Reference and Intercomparison Materials for Stable Isotopes of Light Elements", International Atomic Energy Agency, Vienna, Austria, IAEATECHDOC- 825, 1995.

[0044] The percentage of biogenic carbon content is calculated by dividing pMC by REF and multiplying the result by 100. For example, [102(pMC) / 102(REF)]×100=100% biogenic carbon. The results are expressed as the mass percentage (wt%) of biogenic carbon relative to the total carbon mass in the compound.

[0045] [Table 1]

[0046] In the context of the present invention, the term "segregated" means a material stream that is distinctive and distinguishable from other material streams in the value chain (e.g. a product manufacturing process) and is therefore considered to belong to a collection of materials with comparable properties, such that the same origin of the material or its production according to the same standards or norms can be traced and guaranteed throughout this value chain.

[0047] For example, this may be the case when a chemist purchases 100% bio-based acetaldehyde exclusively from a single supplier that guarantees the 100% bio-based origin of the delivered acetaldehyde, and the chemist processes this 100% bio-based acetaldehyde separately from other potential sources of acetaldehyde to produce a chemical compound. If the produced chemical compound is made exclusively from the 100% bio-based acetaldehyde, then the chemical compound is 100% bio-based.

[0048] In the context of the present invention, the term "non-segregated" is understood to mean, in contrast to the term "segregated", a material flow that cannot be distinguished from other material flows in the value chain.

[0049] To better understand this concept of sequestration, it is useful to recall some basics about the circular economy and its practical applications in processes, particularly chemical transformations.

[0050] According to the French Environment and Energy Management Agency (ADEME), the circular economy can be defined as an economic system of trade and production that seeks to improve the efficiency of resource use and reduce environmental impact at all stages of the life cycle of products (goods and services) whilst promoting individual well-being. In other words, it is an economic system dedicated to efficiency and sustainability, minimizing waste by optimizing the value created by resources. The circular economy relies heavily on various conservation and recycling practices to move away from the current more linear "take, make, dispose" approach.

[0051] In the field of chemistry, the science of transforming one substance into another, this translates to reusing materials that have already been used to create a product. In theory, all chemicals can be isolated from others and therefore recycled separately. The reality is more complicated, especially in industry, where even when isolated, compounds are often not distinguishable from the same compounds originating from another source, thus complicating the traceability of recycled materials.

[0052] For this reason, various traceability models have been developed that take into account these industrial realities, allowing chemical industry users to manage material flows with full knowledge of the facts and allowing end customers to understand and know in a simple way the origin of the materials used in the production of their object or commodity.

[0053] These models were developed to build transparency and trust throughout the value chain, ultimately allowing end users or customers to choose more sustainable solutions by knowing the percentage of the desired ingredient (e.g. bio-based properties) in their object or commodity, without having the ability to control every aspect of the process themselves.

[0054] One such model is the "segregation" defined above. Known examples where this model applies include glass and some metals, where the material flow can be tracked separately.

[0055] However, chemicals are often used in complex combinations and it is very often difficult to implement separate cycles, especially due to prohibitive costs and very complex flow management, so the "segregation" model is not always applicable.

[0056] As a result, when it is not possible to distinguish between material flows, other models are applied, and these models are grouped together under the term "non-segregated", for example, involving considering the ratio of a particular flow to other flows without physically separating the flows. One example is the material balance approach.

[0057] The material balance method involves accurately tracking the percentage of a category (e.g. "recycled") in a production system relative to the total, based on auditable accounting records, to ensure a proportionate and appropriate allocation of that category's content in the final product.

[0058] For example, this may be the case when a chemist purchases 50% biogenic acetaldehyde from a supplier who has guaranteed according to a material or mass balance method that in the delivered acetaldehyde, 50% of the acetaldehyde has a biogenic origin and 50% is not of actual biogenic origin, and the chemist uses another stream of this 50% biogenic acetaldehyde and 0% biogenic acetaldehyde, and the two streams become indistinguishable at some point during the production process, for example by mixing. If a produced chemical compound is made from 50% biogenic 50wt% guaranteed acetaldehyde and 0% biogenic 50wt% acetaldehyde, the chemical compound is 25% biogenic.

[0059] For example, a set of globally shared and standardized rules (ISCC+, ISO 14020) has been developed to ensure the management of material flows, guaranteeing stated “bio-based” figures and encouraging the use of recycled raw materials in the production of new products.

[0060] In the context of the present invention, the term "recycled" is understood to mean the origin of a chemical compound which is derived from a process for recycling materials generally considered waste, i.e. which results from one or more transformations carried out using at least one recycling process on at least one material generally considered waste.

[0061] The term "water-soluble polymer" refers to a polymer that is soluble in water at 20 g.L -1 is understood to mean a polymer which, when dissolved by stirring at a concentration of

[0062] Method according to the invention The present invention therefore relates to a process for obtaining N-vinylformamide, which comprises the reaction between acetaldehyde and formamide, one of the two, preferably both, being at least partially renewable and non-fossil.

[0063] More specifically and preferentially, the compounds used to obtain N-vinylformamide and containing the carbon atoms found in the N-vinylformamide molecule are partially or entirely renewable and non-fossil. These compounds are acetaldehyde and formamide.

[0064] The acetaldehyde preferably has a biogenic carbon content in the range of 5 wt% to 100 wt% based on the total carbon mass in said acetaldehyde, the biogenic carbon content being measured according to ASTM D6866-21 Method B.

[0065] The formamide preferably has a bio-based carbon content in the range of 5 wt % to 100 wt % based on the total carbon mass in said formamide, the bio-based carbon content being measured according to ASTM D6866-21 Method B.

[0066] In the present invention as a whole, the biogenic carbon content of a compound that is defined as being at least partially renewable and non-fossil or that is defined as having a biogenic carbon content is preferably 5 wt% to 100 wt%, preferably 10 wt% to 100 wt%, preferably 15 wt% to 100 wt%, preferably 20 wt% to 100 wt%, preferably 25 wt% to 100 wt%, preferably 30 wt% to 100 wt%, preferably 35 wt% to 100 wt%, preferably 40 wt% to 100 wt%, preferably 45 wt% to 100 wt%, more preferably 50 wt% to 100 wt%, more preferably 60 wt% to 100 wt%, more preferably 70 wt% to 100 wt%, more preferably 80 wt% to 100 wt%, more preferably 90 wt% to 100 wt%, more preferably 100 wt% to 100 wt%, more preferably 15 ... 00wt%, preferably 50wt% to 100wt%, preferably 55wt% to 100wt%, preferably 60wt% to 100wt%, preferably 65wt% to 100wt%, preferably 70wt% to 100wt%, preferably 75wt% to 100wt%, preferably 80wt% to 100wt%, preferably 85wt% to 100wt%, preferably 90wt% to 100wt%, preferably 95wt% to 100wt%, preferably 97wt% to 100wt%, preferably 99wt% to 100wt%, and the bio-derived carbon content is measured according to ASTM D6866-21 Method B.

[0067] Preferentially, the acetaldehyde has a biogenic carbon content ranging from 50 wt.% to 100 wt.%, preferably 100 wt.%, relative to the total carbon mass in said acetaldehyde, the biogenic carbon content being measured according to ASTM D6866-21 method B.

[0068] Preferentially, the formamide has a bio-based carbon content of 100 wt% relative to the total carbon mass in said formamide, the bio-based carbon content being measured according to ASTM D6866-21 method B.

[0069] Preferably, acetaldehyde is totally renewable and non-fossil. Preferably, formamide is totally renewable and non-fossil. Preferably, acetaldehyde and formamide are totally renewable and non-fossil.

[0070] The acetaldehyde and / or formamide, preferably both, may be not sequestered, may be partially sequestered, or may be completely sequestered.

[0071] If acetaldehyde and / or formamide are totally renewable and non-fossil, they can be either: a) entirely of recycled origin; a)1) or totally isolated; a)2) or partially isolated; a) 3) or not in quarantine; b) or are partly of recycled origin; b) 1) or totally isolated; b) 2) or partially isolated; b) 3) or not in quarantine; c) or entirely of non-recycled origin; c) 1) or totally isolated; c) 2) or partially isolated; c) 3) or not in isolation.

[0072] In these various embodiments, when acetaldehyde and / or formamide are partially sequestered, the mass ratio between the "sequestered" and "non-sequestered" portions is preferably 99:1 to 10:90, preferably 99:1 to 30:70, more preferably 99:1 to 50:50.

[0073] Among these various embodiments, the three a) embodiments, the three b) embodiments and the embodiment c)1) are preferred. Among these embodiments, the embodiments a)1), a)2), b)1), b)2) and c)1) are even more preferred. The two most preferred embodiments are a)1) and b)1).

[0074] Preferably, acetaldehyde and / or formamide, preferably both, are partially or totally sequestered.

[0075] Preferably, acetaldehyde and / or formamide, preferably both, are partially sequestered or totally recycled.

[0076] Industrial reality is such that it is not always possible to obtain industrial quantities of acetaldehyde and / or formamide that are biologically derived, totally recycled and / or sequestered, or highly recycled and sequestered.Therefore, the above preferences may be more difficult to implement at present.From a practical point of view, embodiments a)3), b)3) and c) are now implemented more easily and on a larger scale.Technologies are evolving rapidly toward a circular economy, and it is certain that the preferred aspects that are already applicable will soon be applicable on a very large scale.

[0077] In the case where acetaldehyde and / or formamide are partly renewable and non-fossil, a distinction is made between the renewable part (biologically derived) and the non-biologically derived part, each of which may obviously follow the same embodiments a), b) and c) described herein above.

[0078] With regard to the partially bio-derived acetaldehyde and / or formamide bio-derived moieties, the same preferences apply as when the compound is entirely bio-derived.

[0079] However, for the non-biological part of the partially bio-based compound, it is even more preferable to have as large a recycled content as possible for a circular economy approach. Therefore, in this case, the embodiments a)1), a)2), b)1), b)2), in particular a)1) and b)1), are preferred.

[0080] The acetaldehyde is preferably obtained from either ethanol, which is preferably at least partially, preferably entirely, derived from biomass, or ethylene, which is preferably at least partially, preferably entirely, derived from biomass.

[0081] Formamide is preferably produced from formic acid, which is preferably derived at least partially, preferably entirely, from biomass, or ethyl formate, which is preferably derived at least partially, preferably entirely, from biomass, or CO, which is considered to be at least partially, preferably entirely, from renewable and non-fossil sources. 2 The carbon monoxide may be derived from either the recycled carbon monoxide or from the recycled carbon monoxide.

[0082] With regard to the reaction between acetaldehyde and formamide to form N-vinylformamide, the skilled person can refer to already established knowledge. Preferentially, the method for obtaining N-vinylformamide is by the "alkoxy" process, especially when the alcohol used as the protecting agent is methanol.

[0083] In the first step, acetaldehyde is contacted with formamide in the presence of a solvent and a base. Preferentially, the reaction solvent is toluene and the base is potassium bicarbonate. A synthesis reactor is charged with a mixture of toluene and acetaldehyde.

[0084] Further, potassium bicarbonate is mixed with formamide, and the mixture is added successively to the mixture of toluene and acetaldehyde. This addition order is preferred. In an alternative embodiment, the mixture of formamide and potassium carbonate is added successively to the mixture of toluene and acetaldehyde. The reaction time is generally 0.5 hours to 10 hours, preferably 1 to 7 hours.

[0085] The molar ratio between acetaldehyde and formamide is generally in the range of 5:1 to 1:5, preferably 2:1 to 1:2. The reaction temperature is generally in the range of 0°C to 40°C, preferably 15°C to 30°C.

[0086] The hydroxyethylformamide thus formed crystallizes and precipitates in the reaction medium, and in order to control the crystallization, it is preferred to seed the mixture of toluene and acetaldehyde with hydroxyethylformamide crystals and then add a mixture of formamide and potassium bicarbonate.

[0087] At the end of this first step, the hydroxyethylformamide crystals are separated from the solvent by a filtration step. In a non-limiting embodiment, the filtration device can be a Nutsche filter, a filter press, a vertical or horizontal centrifuge, a rotary filter under vacuum or pressure, or simply a filter in the reactor if the reactor is equipped with a grid at the drain with a mesh suitable for retaining the hydroxyethylformamide crystals.

[0088] In the second step, methanol is added to the hydroxyethylformamide crystals. Methanol plays the role of both solvent and reagent in this step. The molar ratio between methanol and hydroxyethylformamide is generally 20:1 to 1:2, preferably 5:1 to 1:1.

[0089] The etherification reaction is catalyzed by an acid source, preferably a Bronsted acid. Any organic or inorganic acid source may be suitable, but preferentially sulfuric acid is chosen.

[0090] The sulfuric acid serves both to neutralize the residual potassium bicarbonate used in the first step and to act as a reaction catalyst.

[0091] The reaction temperature is generally 5-80° C., more preferentially 10-40° C. The reaction time between hydroxyethylformamide and methanol is 0.5-10 hours, more preferably 1-8 hours. The reaction product is methoxyethylformamide in liquid form.

[0092] The methoxyethylformamide is then purified to remove excess methanol and toluene. Preferentially, this purification is carried out by at least one vacuum distillation column.

[0093] In the third and final step, the methoxyethylformamide thus obtained is subjected to a thermolysis reaction in the gas phase. First, the methoxyethylformamide is heated and vaporized. Then, the vapor of the methoxyethylformamide is introduced into a pyrolyzer tube and subjected to thermolysis. The tube is generally heated to a temperature of 200 to 600°C, preferably 250 to 550°C.

[0094] According to one embodiment, the method is for obtaining N-vinylformamide by the alkoxy process, in which methanol is used as a protecting agent, and the method comprises thermolysis of N-methoxyethylformamide, preferably at a temperature between 200° C. and 600° C. and under atmospheric pressure or partial vacuum.

[0095] The pyrolyzer may be operated at atmospheric pressure or under partial vacuum, preferentially under partial vacuum, more preferentially at an absolute pressure below 100 mbar.

[0096] The N-vinylformamide gas thus formed is generally cooled either by a condenser or a gas scrubber fed with pre-cooled liquid N-vinylformamide. The liquid thus obtained is a mixture of N-vinylformamide and methanol. An optional additional step is the evaporation of methanol in a falling film evaporator, flash evaporator, rotary evaporator or distillation column, etc.

[0097] Monomers according to the invention The present invention further relates to bio-based N-vinylformamide having a bio-based carbon content ranging from 5 wt% to 100 wt% based on the total carbon mass in the N-vinylformamide, the bio-based carbon content being measured according to ASTM D6866-21 method B. The same embodiments and preferences developed in the "Methods" section apply to this section of the monomer description.

[0098] The present invention also relates to a bio-based N-vinylformamide obtained by reaction between acetaldehyde and formamide, wherein said acetaldehyde and / or said formamide, preferentially both, have a bio-based carbon content of 5 wt.% to 100 wt.%, based on the total carbon mass in said acetaldehyde and / or said formamide, respectively, wherein the bio-based carbon content is measured according to ASTM D6866-21 method B.

[0099] Preferably, acetaldehyde is totally renewable and non-fossil. Preferably, formamide is totally renewable and non-fossil. Preferably, acetaldehyde and formamide are totally renewable and non-fossil.

[0100] Throughout the present invention, "biogenic N-vinylformamide" is understood to mean N-vinylformamide that is at least partially, preferably entirely, derived from biomass, i.e. is the result of one or more chemical transformations carried out on one or more raw materials having an origin as opposed to a natural, non-fossil origin. Biogenic N-vinylformamide may also be referred to as bioderived or biosourced N-vinylformamide.

[0101] The acetaldehyde and / or formamide, preferably both, may be non-sequestered, partially sequestered, or completely sequestered. The preferences developed in the "Methods" section apply in this section describing the monomers.

[0102] In certain embodiments, acetaldehyde and / or formamide, preferably both, may be partially or totally recycled. The preferences developed in the "Method" section apply in this section describing the monomers.

[0103] In this particular embodiment, the monomer according to the invention can be prepared by the following steps: - recycling at least one renewable and non-fossil raw material to obtain acetaldehyde and / or formamide; - reacting acetaldehyde and / or formamide to obtain N-vinylformamide monomer; The method is obtained by a method comprising the steps of:

[0104] Polymers according to the invention The present invention relates to a polymer obtained by polymerization of at least one N-vinylformamide monomer obtained by the method according to the invention. The present invention also relates to a polymer obtained by polymerization of at least one N-vinylformamide monomer as described above. The same embodiments and preferences as developed in the "Method" section apply to this section.

[0105] The polymers according to the invention are preferably water-soluble or water-swellable. The polymers may also be superabsorbents.

[0106] The polymer according to the invention may be a homopolymer having at least one N-vinylformamide monomer obtainable by the process according to the invention, or a copolymer having at least one of the aforementioned N-vinylformamide monomers and having at least one different additional monomer, advantageously chosen from at least one nonionic monomer, and / or at least one anionic monomer, and / or at least one cationic monomer, and / or at least one zwitterionic monomer, and / or at least one monomer comprising a hydrophobic group.

[0107] Thus, the copolymer may comprise at least a second monomer different from the first monomer (N-vinylformamide according to the invention), this second monomer being selected from nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, monomers comprising hydrophobic groups, and mixtures thereof.

[0108] The non-ionic monomer is preferably selected from acrylamide, methacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-methylol acrylamide, N-vinylformamide (NVF), N-vinylacetamide, N-vinylpyridine and N-vinylpyrrolidone (NVP), N-vinylimidazole, N-vinylsuccinimide, acryloylmorpholine (ACMO), acryloyl chloride, glycidyl methacrylate, glyceryl methacrylate and diacetone acrylamide.

[0109] The anionic monomer is preferably selected from acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, acrylamido undecanoic acid, 3-acrylamido 3-methylbutanoic acid, maleic anhydride, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), vinylsulfonic acid, vinylphosphonic acid, allylsulfonic acid, methallylsulfonic acid, 2-sulfoethyl methacrylate, sulfopropyl methacrylate, sulfopropyl acrylate, allylphosphonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanedisulfonic acid, and water-soluble salts of these monomers, such as their alkali metal, alkaline earth metal or ammonium salts. The anionic monomer is preferably acrylic acid (and / or its salts) and / or ATBS (and / or its salts).

[0110] The cationic monomer is preferably selected from quaternized dimethylaminoethyl acrylate (ADAME), quaternized dimethylaminoethyl methacrylate (MADAME), dimethyldiallylammonium chloride (DADMAC), acrylamidopropyltrimethylammonium chloride (APTAC), and methacrylamidopropyltrimethylammonium chloride (MAPTAC).

[0111] The zwitterionic monomers may be derivatives of vinyl type units, in particular acrylamide, acrylic acid, allyl acid or maleic acid, which have an amine or ammonium function (advantageously quaternary) and an acid function of the carboxylic acid (or carboxylate), sulfonic acid (or sulfonate) or phosphoric acid (or phosphate) type.

[0112] Monomers with hydrophobic properties can also be used to prepare the polymers.Preferably, these are selected from the group consisting of esters of (meth)acrylic acid with alkyl, arylalkyl, propoxylated, ethoxylated or ethoxylated and propoxylated chains, derivatives of (meth)acrylamide with alkyl, arylalkyl, propoxylated, ethoxylated, ethoxylated and propoxylated chains or dialkyl, alkylarylsulfonates, or derivatives of mono- or di-substituted amides of (meth)acrylamide with propoxylated, ethoxylated, or ethoxylated and propoxylated alkyl, arylalkyl chains, derivatives of (meth)acrylamide with propoxylated, ethoxylated, ethoxylated and propoxylated alkyl, arylalkyl or dialkyl chains, alkylarylsulfonates.

[0113] Each of these monomers may also be of biological origin.

[0114] According to the invention, the polymers may have linear, branched, star, comb, dendritic or block structures, which can be obtained by choosing the initiator, the transfer agent, the polymerization technique such as controlled radical polymerization called RAFT (reversible addition-fragmentation chain transfer), NMP (nitroxide mediated polymerization) or ATRP (atom transfer radical polymerization), the incorporation and the concentration of structural monomers.

[0115] According to the present invention, the polymer is advantageously linear and structured.Structured polymer refers to a non-linear polymer with side chains to obtain a significant entanglement state that results in a very substantial low gradient viscosity when the polymer is dissolved in water.The polymer of the present invention may also be crosslinked.

[0116] Furthermore, the polymers according to the invention may be structured by: at least one structuring agent, which may be selected from the group comprising polyethylenically unsaturated monomers (having at least two unsaturated functionalities), such as, for example, vinyl functional groups, in particular allyl, acrylic and epoxy functional groups, and which may, for example, be mentioned methylenebisacrylamide (MBA), triallylamine or tetraallylammonium chloride, or 1,2 dihydroxyethylenebis-(N-acrylamide), and / or macroinitiators, such as polyperoxides, polyazides, and polytransfer agents, such as polymeric (co)polymers and polyols, and / or - Functionalized polysaccharides.

[0117] The amount of branching / crosslinking agent in the monomer mixture is advantageously less than 4 wt.%, more advantageously less than 1%, and even more advantageously less than 0.5% relative to the monomer content (by weight). According to a particular embodiment, the amount of branching / crosslinking agent may be at least equal to 0.00001 wt.% relative to the monomer content.

[0118] In a particular embodiment, the polymer according to the invention may be a semi-synthetic and therefore semi-natural polymer. In this embodiment, the polymer may be synthesized by copolymerization, by total or partial grafting, of at least one monomer according to the invention with at least one natural compound, said natural compound being preferably selected from starch and its derivatives, polysaccharides and its derivatives, fibres, vegetable gums, animal gums or algal gums, and modified forms thereof. For example, the vegetable gums may include guar gum, gum arabic, locust bean gum, tragacanth gum, guanidinium gum, cyanin gum, tara gum, cassia gum, xanthan gum, ghatti gum, karaya gum, gellan gum, cyanopsis tetragonoloba gum, soybean gum, or beta-glucan or dammar. The natural compound may also be gelatin, casein or chitosan. For example, the algal gums may include sodium alginate or its acid, agar or carrageenan.

[0119] The polymerization is generally carried out by, but not limited to, copolymerization or grafting. The skilled person can refer to the current general knowledge in the field of semi-natural polymers.

[0120] The present invention also relates to a composition comprising at least one polymer according to the invention and at least one natural polymer, said natural polymer being preferably selected from the natural polymers mentioned above. The mass ratio between the synthetic polymer and the natural polymer is generally 90:10 to 10:90. The composition may be in liquid, inverse emulsion or powder form.

[0121] Generally, the polymer does not need to be developed by a specific polymerization method. In fact, the polymer can be obtained according to any polymerization technique known to those skilled in the art. In particular, the polymerization technique can be solution polymerization, gel polymerization, precipitation polymerization, emulsion polymerization (aqueous or inverse), suspension polymerization, reactive extrusion polymerization, water-in-water polymerization, or micellar polymerization.

[0122] The polymerization is generally a free radical polymerization, preferably by inverse emulsion or gel polymerization, including free radical polymerization using UV, azo, redox or thermal initiators, and controlled radical polymerization (CRP) techniques, or matrix polymerization techniques.

[0123] The polymers according to the invention can be modified after they have been obtained by polymerization. This is known as post-modification of polymers. All known post-modifications can be applied to the polymers according to the invention, and the invention also relates to the polymers obtained after said post-modification. Among the possible post-modifications that are explained below, post-hydrolysis, post-modification by Mannich reaction, post-modification by Hofmann reaction and post-modification by glyoxalation reaction can be mentioned.

[0124] The polymer according to the invention can be obtained by carrying out a post-hydrolysis reaction on at least one monomer obtained by the process according to the invention or on a polymer obtained by polymerization of at least one monomer as described above in the "monomer" section. Before the post-hydrolysis, the polymer comprises, for example, an acrylamide or methacrylamide monomer unit. The polymer may also further comprise a monomer unit of N-vinylformamide. More specifically, the post-hydrolysis comprises the reaction of a hydrolyzable functional group, advantageously an amide or ester functional group, of a non-ionic monomer unit with a hydrolysis agent. This hydrolysis agent may be an enzyme, an ion exchange resin, an alkali metal or a suitable acid compound. Preferably, the hydrolysis agent is a Brönsted base. If the polymer comprises amide and / or ester monomer units, the post-hydrolysis reaction produces carboxylate groups. If the polymer comprises vinylformamide monomer units, the post-hydrolysis reaction produces amine groups.

[0125] The polymer according to the invention can be obtained by carrying out a Mannich reaction on at least one monomer obtained by the method according to the invention or on a polymer obtained by polymerization of at least one monomer as described above in the "monomer" section. More specifically, before the Mannich reaction, the polymer advantageously comprises acrylamide and / or methacrylamide monomer units. The Mannich reaction is carried out in aqueous solution in the presence of a dialkylamine and a formaldehyde precursor. More advantageously, the dialkylamine is dimethylamine and the formaldehyde precursor is formaldehyde itself. After this reaction, the polymer comprises a tertiary amine.

[0126] The polymer according to the invention can be obtained by carrying out a Hoffmann reaction on at least one monomer obtained by the process according to the invention or on a polymer obtained by polymerization of at least one monomer as described above in the "monomer" section. Prior to the Hoffmann reaction, the polymer advantageously comprises acrylamide and / or methacrylamide monomer units. The so-called Hoffmann degradation reaction is carried out in aqueous solution in the presence of alkaline earth and / or alkali hydroxides and alkaline earth and / or alkali hypohalides.

[0127] Discovered by Hoffmann at the end of the 19th century, this reaction is used to convert an amide functional group into a primary amine functional group, which has one less carbon atom. The detailed reaction mechanism is shown below.

[0128] In the presence of a Bronsted base (eg soda), a proton is abstracted from the amide.

[0129] [ka]

[0130] The formed amidate ions are then converted to hypochlorite (e.g. NaClO at equilibrium: 2NaOH + Cl 2 ⇔NaClO + NaCl + H 2O) active chlorine (Cl 2 ) to produce N-chloramide. A Brønsted base (e.g., NaOH) abstracts a proton from the chloramide to form an anion. The anion loses a chloride ion to form a nitrene that undergoes isocyanate rearrangement.

[0131] [ka]

[0132] The reaction between hydroxide ions and isocyanates forms carbamates.

[0133] [ka]

[0134] Decarboxylation from carbamates (CO 2 After removal of the aryl group, the primary amine is obtained.

[0135] [ka]

[0136] To convert all or part of the amide functionalities of a (co)polymer containing amide groups to amine functionalities, two main factors come into play (expressed in molar ratios): these are: - alpha = (alkali and / or alkaline earth hypohalite / amide group) and - beta = (alkali and / or alkaline earth hydroxides / alkali and / or alkaline earth hypohalides).

[0137] The polymer according to the invention can also be obtained by carrying out a glyoxalation reaction on at least one monomer obtained by the process according to the invention or on a polymer obtained by polymerization of at least one monomer as described above in the "monomer" section, said polymer advantageously comprising at least one monomer unit of acrylamide or methacrylamide by glyoxalation reaction. More specifically, the glyoxalation reaction comprises the reaction of at least one aldehyde on a polymer, thereby making it possible to functionalize said polymer. Advantageously, the aldehyde can be selected from the group comprising glyoxal, glutaraldehyde, furandialdehyde, 2-hydroxyadipaldehyde, succinaldehyde, starch dialdehyde, 2.2-dimethoxyethanal, diepoxy compounds, and combinations thereof. Preferably, the aldehyde compound is glyoxal.

[0138] According to the present invention, the polymer may be in liquid, gel or solid form, if the preparation of the polymer includes a drying step such as spray drying, drum drying, radiation drying such as microwave drying, or fluidized bed drying.

[0139] According to the invention, the water-soluble polymer preferably has a molecular weight of 10 to 40 million g / mol. The polymer may be a dispersant, in which case its molecular weight is preferably 1000 to 50,000 g / mol. The polymer may have a higher molecular weight, typically 1 to 30 million g / mol. The molecular weight is understood as the weight average molecular weight. The polymer according to the invention may also be a superabsorbent, capable of absorbing 10 to 500 times its mass in water.

[0140] The molecular weight is advantageously determined by the intrinsic viscosity of the (co)polymer. The intrinsic viscosity can be measured by methods known to those skilled in the art and can be calculated from the reduced viscosity values ​​of different (co)polymer concentrations by a graphical method that involves plotting the reduced viscosity values ​​(y-axis) against the concentration (x-axis) and extrapolating the curve to zero concentration. The intrinsic viscosity values ​​are plotted on the y-axis or using the least squares method. The molecular weight can then be determined using the Mark-Houwink formula: [η] = KM α [η] represents the intrinsic viscosity of the (co)polymer determined by solution viscometry. K represents an empirical constant. M represents the molecular weight of the (co)polymer. α represents the Mark-Houwink coefficient. K and α depend on the particular (co)polymer-solvent system.

[0141] The comonomers which are combined with the monomers according to the invention to obtain the polymers of the invention are preferably at least partially, more preferably entirely, renewable and non-fossil.

[0142] Thus, in a preferred embodiment, the present invention relates to a polymer comprising: - at least 5 mol %, preferably at least 10 mol %, preferably between 20 mol % and 99 mol %, more preferably between 30 mol % and 90 mol %, of a first monomer, said monomer being a monomer according to the invention, and - at least one second monomer comprising at least 1 mol %, preferably between 5 mol % and 90 mol %, more preferably between 10 mol % and 80 mol % of ethylenic unsaturation, said second monomer being different from the first monomer and being at least partially renewable and non-fossil.

[0143] Thus, in a preferred embodiment, the present invention relates to a polymer comprising: - at least 5 mol %, preferably at least 10 mol %, preferably between 20 mol % and 99 mol %, more preferably between 30 mol % and 90 mol %, of a first monomer, said monomer being a monomer according to the invention, and at least one second monomer comprising at least 1 mol %, preferably between 5 mol % and 90 mol %, more preferably between 10 mol % and 80 mol % of ethylenic unsaturation, said second monomer being different from the first monomer and being at least partially renewable and non-fossil, - at least one third monomer comprising at least 1 mol %, preferably between 5 mol % and 90 mol %, more preferably between 10 mol % and 80 mol % of ethylenic unsaturation, said third monomer being different from the first and second monomers and being at least partially renewable and non-fossil.

[0144] A polymer according to the present invention may comprise four or more different monomers.

[0145] In a preferred embodiment, the second monomer, and possibly other monomers, have a bio-based carbon content in the range of 5 wt.% to 100 wt.%, preferably 10 wt.% to 100 wt.%, based on the total carbon mass in the relevant monomers, the bio-based carbon content being measured according to ASTM D6866-21 Method B.

[0146] In a preferred embodiment according to the present invention, the second monomer and any other monomers are selected from the group consisting of acrylamide, (meth)acrylic acid and / or its salts, 2-acrylamido-2-methylpropanesulfonic acid (ATBS) and / or its salts, N-vinylpyrrolidone (NVP) dimethylaminoethyl (meth)acrylate and its quaternized forms, dimethyldiallylammonium chloride (DADMAC), dimethylaminoethyl (meth)acrylate and its quaternized forms, dimethyldiallylammonium chloride (DMCA), dimethylaminoethyl (meth)acrylate and its quaternized forms, ... 2 =CHCO-NR 1 R 2 A substituted acrylamide having the formula: 1 and R 2 are each independently a linear or branched carbon chain Cn H 2n+1 and n is selected from substituted acrylamides in the range of 1 to 10.

[0147] Throughout the present invention, it is understood that the molar percentages of monomers (excluding crosslinkers) of a polymer equal 100%.

[0148] The present invention also relates to at least one N-vinylformamide monomer obtained according to the process according to the invention, or to a polymer obtained by polymerization of said at least one N-vinylformamide monomer, which is then partially or totally hydrolyzed by acid or base hydrolysis to convert at least one N-vinylformamide monomer unit into N-vinylamine.

[0149] In this embodiment, the polymer before hydrolysis is preferentially a polymer comprising at least 80 mol% of N-vinylformamide monomer units. Preferentially, the polymer is an N-vinylformamide homopolymer. The hydrolysis rate may range from 20 to 100%, preferably from 25 to 90%, even more preferably from 30 to 80%, this ratio representing the percentage of N-vinylformamide monomer units converted into vinylamine monomer units relative to the total number of N-vinylformamide monomer units present in the polymer before hydrolysis.

[0150] In this embodiment, the hydrolysis is preferentially carried out on an N-vinylformamide homopolymer. The polymer obtained after hydrolysis is a vinylformamide / vinylamine copolymer or a vinylamine homopolymer. The molar percentage of vinylamine units in said polymer (or homopolymer) is preferentially in the range of 20-100%, preferably 25-90% and even more preferably 30-80%.

[0151] Preferably, the polymer according to the present invention comprises a bio-based carbon content in the range of 5 wt% to 100 wt% based on the total carbon mass in said polymer, the bio-based carbon content being measured according to ASTM D6866-21 method B.

[0152] The present invention also relates to the use of at least one N-vinylformamide monomer according to the invention or obtainable according to the process described above for synthesizing a polymer.

[0153] Use of the polymer according to the invention The invention also relates to the use of the polymers according to the invention in the recovery of hydrocarbons (oil and / or gas), in the drilling and cementing of wells, in the stimulation of hydrocarbon wells (oil and / or gas), e.g. hydraulic fracturing, adaptation, diversion, the treatment of water in open, closed or semi-closed circuits, the treatment of fermentation slurries, the treatment of sludges, papermaking, construction, wood processing, hydraulic composition treatment (concrete, cement, mortar and aggregates), mining, the formulation of cosmetics, the formulation of detergents, textile production, battery component production, geothermal energy, sanitary napkin production or in agriculture.

[0154] The present invention also relates to the use of the polymers according to the invention as flocculants, coagulants, binders, fixatives, viscosity reducers, thickeners, absorbents, friction reducers, water removal agents, drainage agents, charge retention agents, dehydration agents, conditioning agents, stabilizing agents, film formers, sizing agents, superplasticizers, clay inhibitors or dispersants.

[0155] Methods of using the polymers according to the present invention The present invention also relates to various methods, described below, of using the polymers of the present invention to improve coating performance.

[0156] The present invention also relates to a method for producing a method for manufacturing a semiconductor device comprising the steps of: a. preparing an injection fluid from a polymer according to the present invention using water or brine; b. injecting an injection fluid into the subterranean formation; c. flooding the subsurface formation with an injection fluid; d. Recovering the aqueous mixture of oil and / or gas. The present invention relates to a method for enhancing oil or gas recovery by flooding a subterranean formation, comprising:

[0157] The present invention also relates to a method for producing a method for manufacturing a semiconductor device comprising the steps of: a. preparing an injection fluid from a polymer according to the present invention with water or brine and with at least one proppant; b. injecting said fluid into an underground reservoir and fracturing at least a portion thereof to recover oil and / or gas. The present invention relates to a method for hydraulic fracturing of an underground oil and / or gas reservoir, comprising:

[0158] In the above-mentioned method, the polymer is preferably a high molecular weight polymer (greater than 8 million Daltons). The polymer is preferably linear. The polymer is preferably in the form of a powder, an inverse emulsion, a partially dehydrated inverse emulsion, or "clear", i.e. a dispersion of solid polymer particles in an aqueous or oily fluid. The powder form is preferably obtained by gel or spray drying of the inverse emulsion. The powder form also includes compositions comprising inverse emulsions of the polymer according to the invention, and solid particles of the polymer according to the invention.

[0159] The present invention also relates to a method for producing a method for manufacturing a semiconductor device comprising the steps of: a. preparing an injection fluid from a polymer according to the present invention using water or brine; b. injecting an injection fluid into the subterranean formation; c. partially or completely plugging the subterranean formation with an injection fluid, said plugging being temporary or permanent. The present invention relates to a method for stimulating a subsurface formation, comprising:

[0160] The present invention also relates to a method for producing a method for manufacturing a semiconductor device comprising the steps of: a. preparing an injection fluid from a polymer according to the present invention using water or brine; b. injecting said drilling and / or cementing fluid into the subterranean formation through a drill head during at least one step of drilling or cementing a well. The present invention relates to a method for drilling and / or cementing a well in a subterranean formation, comprising:

[0161] Drilling and cementing of a well are two successive steps for creating a well in an underground formation. The first step is drilling with a drilling fluid, while the second step is cementing the well with a cementing fluid. The present invention also relates to a method of injecting an intermediate fluid ("spacer fluid") injected between the drilling fluid and the cementing fluid, said intermediate fluid comprising at least one polymer according to the present invention, which prevents contamination between the cementing fluid and the drilling fluid.

[0162] During drilling and cementing of wells, the polymers according to the invention can be used as fluid loss additives in well cement compositions to reduce fluid loss from the cement composition to the permeable formation or zone into or through which the cement composition is pumped. In primary cementing, bridging the annular space between the permeable formation or zone and the drill string cemented thereto prevents the cement composition from being placed along the entire length of the annulus, since fluid, i.e., water loss, into the permeable formation or subterranean zone can lead to premature gelling of the cement composition.

[0163] The present invention also relates to a method for deactivating clay in a hydraulic composition for construction purposes, said method comprising the step of adding to the hydraulic composition or to one of its components at least one clay deactivator, characterized in that the clay deactivator is a polymer according to the invention.

[0164] Clays can absorb water, which reduces the performance of building materials. The use of the polymers of the present invention as clay inhibitors makes it possible to avoid the swelling of clay, which can in particular lead to cracks and thus weaken the building.

[0165] The hydraulic composition may be concrete, cement, mortar or an aggregate. The polymer is added to the hydraulic composition or to one of its components, advantageously in a dose of 2 to 200 ppm of deactivator relative to the mass of the aggregate.

[0166] In this method of passivating clay, the clay includes, but is not limited to, 2:1 swelling clay (such as smectite), or 1:1 swelling clay (such as kaolin), or 2:1:1 swelling clay (such as chlorite). The term "clay" generally refers to magnesium and / or aluminum silicates, including phyllosilicates having a lamellar structure. However, in the present invention, the term "clay" also includes clays that do not have such a structure, such as amorphous clays.

[0167] The invention also relates to a method for producing a sheet of paper, cardboard, etc., in which a step is carried out which comprises adding at least one polymer according to the invention to a suspension of fibres, at one or more injection points, before the sheet is formed. The polymer can provide dry strength or retention properties or wet strength. The polymer can also improve the formation, drainage and water removal capacity of the paper.

[0168] The method can be successfully used in the production of wrapping and cardboard, coated papers, sanitary and household papers, all kinds of paper, cardboard, etc.

[0169] The post-modified polymers described in the "Polymers" section, especially those post-modified by the Hoffmann reaction or the glyoxalation reaction, are particularly advantageous in processes for producing paper, cardboard, and the like.

[0170] Retention properties are understood to mean the ability to retain the suspended substances of the paper pulp (fibers, fines, fillers (calcium carbonate, titanium oxide)...) in the forming fabric and thus in the fibrous mat that constitutes the final sheet. The mode of action of the retention agents is based on flocculating these suspended substances in water. In fact, the formed floc is more easily retained on the forming sheet.

[0171] Filler retention involves the specific retention of fillers (small mineral species with low affinity to cellulose). A significant improvement in filler retention results in white water clarification by retaining the filler in the sheet and increasing its basis weight. This also allows some of the fiber (the most expensive species in the composition of paper, cardboard, etc.) to be replaced by fillers (which are less expensive) in order to reduce production costs.

[0172] With regard to the water removal (or drainage) property, this is the ability of the fibrous mat, particularly during the manufacture of the sheet, to expel or drain the maximum amount of water so that the sheet dries as quickly as possible.

[0173] These two properties (retention and drainage) are intricately related, one dependent on the other, so the problem is to find the optimum compromise between retention and drainage. Generally, those skilled in the art refer to retention and drainage agents, because they are the same type of product used to improve these two properties.

[0174] Fibrous suspension is understood to mean thick or thin pulp consisting of water and cellulose fibres. Thick stocks with a dry matter consistency of more than 1% or even more than 3% are placed upstream of the fan pump. Thin stocks with a dry matter consistency generally less than 1% are placed downstream of the fan pump.

[0175] The polymer may be added to the thick stock or the thin stock. The polymer may be added at the fan pump or the headbox. Preferably, the polymer is added before the headbox.

[0176] In the process for making paper, cardboard etc. according to the invention, the polymer according to the invention may be used alone or in combination with a secondary retention agent. Preferably, a secondary retention agent selected from organic polymers and / or inorganic particulates is added to the fibre suspension.

[0177] This secondary retention agent added to the fibrous suspension is advantageously selected from anionic polymers in the broad sense, which may be (but are not limited to) linear, branched, crosslinked, hydrophobic, associative and / or inorganic particulates (e.g. bentonite, colloidal silica).

[0178] The present invention also relates to a method for treating a suspension of solid particles in water resulting from mining or oil sands operations, comprising a step of contacting said suspension with at least one polymer according to the invention. Such a method can be carried out in a thickener, which is generally a retention zone in the form of a tube several meters in diameter with a conical bottom in which the particles can settle. According to a specific embodiment, the aqueous suspension is transported to the thickener by a pipe and the polymer is added to said pipe.

[0179] According to another embodiment, the polymer is added to a thickener that already contains the suspension to be treated. In a typical mineral processing operation, the suspension is often thickened in a thickener. This results in a denser sludge exiting the bottom of the thickener and an overflow of aqueous fluid (called liquor) released from the treated suspension exiting the top of the thickener. Generally, the addition of the polymer increases the concentration of the sludge and the clarity of the liquor.

[0180] According to another embodiment, the polymer is added to the particulate suspension during the transport of said suspension to the deposition area. Preferably, the polymer is added in the pipe that conveys said suspension to the deposition zone. It is on this deposition area that the treated suspension is spread in preparation for dewatering and solidification. The deposition area may be either an open area, such as an unconfined area of ​​soil, or a closed area, such as a water basin, a cell, etc.

[0181] An example of such a treatment during transportation of the suspension is to spread a suspension treated with a polymer according to the invention on the soil in preparation for dewatering and solidification, and then to spread a second layer of the treated suspension on top of the solidified first layer. Another example is to continuously spread the suspension treated with a polymer according to the invention in such a manner that the treated suspension falls continuously on top of the previously discharged suspension in the deposition area, resulting in the formation of a mass of treated material from which water is extracted.

[0182] According to another embodiment, a water-soluble polymer is added to the suspension and a mechanical treatment such as centrifugation, pressing or filtration is performed.

[0183] The water-soluble polymer can be added simultaneously at different stages of suspension treatment, i.e., for example, in the pipe carrying the suspension to the thickener and in the sludge leaving the thickener which is conveyed either to the settling zone or to a mechanical treatment device.

[0184] The present invention also relates to a method for treating municipal or industrial water, comprising the step of introducing at least one polymer according to the invention into said water to be treated. Effective water treatment requires the removal of dissolved compounds, as well as dispersed and suspended solids, from the water. Generally, this treatment is enhanced by chemicals such as coagulants and flocculants, which are usually added to the water stream before separation devices such as flotation and sedimentation.

[0185] The polymers according to the invention can be advantageously used to coagulate or flocculate suspended particles in municipal or industrial wastewater. Generally, they are used in combination with an inorganic coagulant such as alum.

[0186] They can also be advantageously used in the treatment of the sludge produced from this wastewater treatment. Sewage sludge (whether municipal or industrial) is the main waste product produced by treatment plants from effluents. Generally, sludge treatment involves dewatering. This dewatering can be done by centrifugation, filter press, belt press, electrical dewatering, sludge drying reed beds, solar drying. This is used to reduce the water concentration of the sludge.

[0187] In this municipal or industrial water treatment process, the polymer according to the invention is preferably linear or branched. The polymer is preferably in the form of a powder, an inverse emulsion or a partially dehydrated inverse emulsion. The powder form is preferably obtained by gel or spray drying from an inverse emulsion.

[0188] The present invention also relates to an additive for a cosmetic, dermatological or pharmaceutical composition comprising at least one polymer according to the invention. The present invention also relates to the use of a polymer according to the invention in the preparation of said compositions as a thickening, conditioning, stabilizing, emulsifying, fixing or film-forming agent. The present invention likewise relates to a cosmetic, dermatological or pharmaceutical composition comprising at least one polymer according to the invention.

[0189] Reference may in particular be made to application FR2979821 on behalf of L'OREAL for the description of the preparation of such compositions and the other ingredients of such compositions. Said compositions may be in the form of a milk, a lotion, a gel, a cream, a gel-cream, a soap, a bubble bath, a balm, a shampoo or a conditioner. The use of said compositions for a cosmetic or dermatological treatment method of keratinous materials such as the skin, the scalp, the eyelashes, the eyebrows, the nails, the hair and / or the mucous membranes is also an integral part of the present invention. Such a use comprises the application of the composition to the keratinous materials, optionally followed by rinsing with water.

[0190] The present invention also relates to an additive for a detergent composition, said additive comprising at least one polymer according to the invention. The present invention also relates to the use of a polymer according to the invention in the preparation of said composition as a thickening, conditioning, stabilizing, emulsifying, fixing or film-forming agent. The present invention also relates to a household or industrial detergent composition comprising at least one polymer according to the invention. In particular, for the description of the preparation of such compositions and other components of such compositions, reference may be made to the applicant's application WO2016020622.

[0191] "Household or industrial detergent compositions" are understood to mean compositions for cleaning various surfaces, in particular any kind of hard surfaces such as textile fibers, dishes, floors, windows, wood, metal, or composite surfaces. Such compositions include, for example, detergents for washing clothes manually or in a washing machine, products for washing dishes manually or for dishwashing machines, detergent products for washing kitchen elements, toilets, furniture, floors, windows, and other home interiors, and other cleaning products for universal use.

[0192] The polymers used as additives, for example thickeners, in cosmetic, dermatological, pharmaceutical or detergent compositions are preferably crosslinked. The polymers are preferably in the form of a powder, an inverse emulsion or a partially dehydrated inverse emulsion. The powder form is preferably obtained by spray drying from an inverse emulsion.

[0193] The present invention likewise relates to a thickener for pigment compositions used in textile printing, comprising at least one polymer according to the invention.The present invention also relates to a textile fiber sizing agent, comprising at least one polymer according to the invention.

[0194] The present invention also relates to a process for producing a superabsorbent from a monomer according to the invention, wherein the superabsorbent is obtained from at least one monomer according to the invention, and said superabsorbent is used for absorbing and retaining water in agricultural applications or for absorbing aqueous liquids in sanitary napkins, for example the superabsorbent is a polymer according to the invention.

[0195] The present invention also relates to a method for producing sanitary napkins, in which the polymer according to the invention is used, for example, as a superabsorbent.

[0196] The present invention also relates to the use of the polymer according to the present invention as a battery binder.The present invention also relates to a battery binder composition comprising the polymer according to the present invention, an electrode material and a solvent.The present invention also relates to a method for manufacturing a battery, comprising the steps of making a gel comprising at least one polymer according to the present invention and filling said battery with it.Mention can be made of lithium ion batteries used in various products including medical devices, electric vehicles, aircraft, and most importantly consumer products such as laptops, mobile phones and cameras.

[0197] Generally, a lithium-ion battery (LIB) includes an anode, a cathode, and an electrolyte material, such as an organic solvent containing a lithium salt. More specifically, the anode and cathode (collectively "electrodes") are formed by mixing the electrode active material (negative or positive) with a binder and a solvent to form a paste or sludge, which is then applied to a current collector, such as aluminum or copper, and dried to form a film on the current collector. The anode and cathode are then stacked and rolled, then housed in a pressurized case containing the electrolyte material, all of which are combined to form a lithium-ion battery.

[0198] In lithium batteries, the binder plays several important roles in both mechanical and electrochemical performance. First, the binder helps disperse the other components in the solvent during the manufacturing process (some act as thickeners), thereby allowing for uniform distribution. Second, the binder holds the various components together, including the active components, conductive additives, and current collectors, ensuring that all of these parts remain in contact. Through chemical or physical interactions, the binder connects these separate components, holding them together and ensuring the mechanical integrity of the electrode without significantly affecting electronic or ionic conductivity. Third, the binder often acts as an interface between the electrode and the electrolyte. In this role, the binder can protect the electrode from corrosion or protect the electrolyte from depletion while facilitating the movement of ions across this interface.

[0199] Another important point is that the binder must have some flexibility so as not to crack or develop defects, which can cause problems during battery manufacturing or assembly.

[0200] Given all the roles that the binder plays in the electrode (and in the battery as a whole), the selection of the binder is very important in ensuring good battery performance.

[0201] The present invention also relates to a method for producing a sanitary napkin in which the polymer according to the invention is used, for example as a superabsorbent.

[0202] As mentioned above, a circular economy is an economic system focused on efficiency and sustainability, minimizing waste by optimizing the value created by resources. It relies heavily on various conservation and recycling practices to move away from the current more linear "take, make, waste" approach.

[0203] Therefore, recycling of materials has become a major and growing concern, and recycling processes are rapidly evolving, allowing the production of materials that can be used in the production of new compounds or objects. Recycling of materials is considered a technological advancement, independent of the origin of the material, as long as it can be recycled. The origin of the recycled material can be renewable and non-fossil, but can also be fossil.

[0204] The specific objectives are described below.

[0205] The process for obtaining N-vinylformamide comprises one of two processes, preferentially both of which at least partially, preferentially entirely, are derived from renewable and non-fossil material recycling processes or fossil materials, and a reaction between acetaldehyde and formamide.

[0206] Preferentially, acetaldehyde and / or formamide, preferentially both, are totally "sequestered", i.e. from separate pipelines and are treated separately. In an alternative embodiment, acetaldehyde and / or formamide are partly "sequestered" and partly "not sequestered". In this case, the mass ratio between the "sequestered" and "not sequestered" parts is preferentially between 99:1 and 25:75, preferably between 99:1 and 50:50. In an alternative embodiment, acetaldehyde and / or formamide are totally "not sequestered".

[0207] N-vinylformamide can be obtained by reaction between acetaldehyde and formamide, said acetaldehyde and / or said formamide, preferentially both, being derived at least partly, and preferentially entirely, from a recycling process of renewable and non-fossil materials or from fossil materials.

[0208] A polymer obtained by polymerization of at least one N-vinylformamide monomer as described immediately above.

[0209] Use of polymers obtained by polymerization of at least one N-vinylformamide monomer as described immediately above in oil and / or gas recovery, drilling and cementing wells, stimulation of oil and / or gas wells (e.g. hydraulic fracturing, adaptation, diversion), treatment of water in open, closed or semi-closed circuits, treatment of fermentation slurries, treatment of sludge, papermaking, construction, wood processing, hydraulic composition treatment (concrete, cement, mortar and aggregates), mining, formulation of cosmetics, formulation of detergents, fiber production, battery component production, geothermal energy or agriculture.

[0210] Use of a polymer obtained by polymerization of at least one N-vinylformamide monomer as described immediately above as a flocculant, coagulant, binder, fixative, viscosity reducer, thickener, absorbent, friction reducer, water remover, drainage agent, charge retention agent, dehydration agent, conditioning agent, stabilizing agent, film former, sizing agent, superplasticizer, clay inhibitor or dispersing agent.

[0211] The process is as follows: - recycling at least one renewable and non-fossil or fossil raw material to obtain acetaldehyde and / or formamide, - reacting said acetaldehyde with said formamide to obtain N-vinylformamide; - polymerizing said N-vinylformamide, optionally with another ethylenically unsaturated monomer; A polymer obtainable according to a process comprising: [Brief description of the drawings]

[0212] [Figure 1] FIG. 1 shows NVF formation from acetaldehyde and formamide. [Diagram 2] FIG. 1 shows vacuum drainage performance at 1 kg / mt and 1.5 kg / mt. EXAMPLES

[0213] The following examples relate to the synthesis of bio-based N-vinylformamide (hereinafter abbreviated as NVF) according to the invention, which comprises the reaction between acetaldehyde (hereinafter abbreviated as ACH) and formamide (hereinafter abbreviated as FAM), one of the two, preferably both of at least partially renewable and non-fossil origin (see FIG. 1). They also relate to the synthesis and use of bio-based polymers obtained from at least one bio-based N-vinylformamide monomer according to the invention.

[0214] The following examples will best serve to illustrate the advantages of the present invention.

[0215] Purity test explanation. The synthesis of NVF is carried out in two steps: first, hydroxyethylformamide is obtained from acetaldehyde and formamide, then hydroxyethylformamide is converted to methoxyethylformamide (MEF) by reaction with methanol and a catalyst, and then methoxyethylformamide is pyrolyzed at high temperature to obtain N-vinylformamide.

[0216] The purity of NVF is determined by high performance liquid chromatography according to the following analytical conditions (Table 2).

[0217] [Table 2]

[0218] Using these conditions, the purity of the NVF can be calculated by measuring the areas of the various impurity peaks.

[0219] Quantitative determination of formamide and methoxyethylformamide is performed using a calibration curve of standard substances.

[0220] The retention time for formamide is 1.43 minutes and for methoxyethylformamide is 4.5 minutes.

[0221] I. Synthesis of partially biobased NVF

[0222] Example 1 Synthesis of NVF using partially renewable and non-fossil-origin FAM and fossil-origin ACH The origin of formamide and its 14 A series of tests were performed by varying the C percentage: CE1, a FAM of fossil origin, and Inv1–Inv7, FAMs of partially renewable and non-fossil origin (Table 3).

[0223] 14 The level of C is measured according to method B of the ASTM D6866-21 standard, which makes it possible to characterize the biogenic nature of a chemical compound by determining its level of biogenic carbon.

[0224] "zero" 14 Cwt% is the amount of measurable 14 C represents the complete absence of carbon and thus indicates a fossil carbon source.

[0225] As shown in Table 3, formamide of non-fossil origin can be obtained from various sources such as the processing of residues from the pulp and paper industry ("tall oil"), or agricultural or municipal waste, biomass, or carbon dioxide fermentation or recycling to form the precursors formic acid (from biomethanol) or ethyl formate (from bioethane), or the amino moiety of formamide can be derived from green ammonia.

[0226] For each test the procedure was as follows: 800 g of toluene was added to a 2000 mL reactor equipped with a jacket, stirrer and condenser.

[0227] The reactor is degassed with nitrogen to expel any air present therein.

[0228] The reactor is maintained at a temperature of 20° C. so that 235 g of acetaldehyde can be introduced into it.

[0229] A pouring funnel is charged with 200 g of formamide containing 1.33 g of potassium bicarbonate.

[0230] While maintaining the reaction medium at 20° C., 20% of the contents of the dropping funnel are fed into the reactor over 30 minutes and 0.5 g of hydroxyethylformamide crystals are added to the reaction medium as crystallization seeds. After a waiting period of 30 minutes, the remaining amount of formamide and potassium bicarbonate contained in the dropping funnel are added to the reaction medium over a period of 3 hours. The temperature is maintained at 20° C. during the reaction to prevent loss of acetaldehyde by evaporation.

[0231] The hydroxyethylformamide obtained is a white solid suspended in toluene, which is separated by Büchner filtration. The solid obtained is again introduced into the reactor and 430 g of methanol and 3.5 g of concentrated sulfuric acid 98% in water are added. The mixture is heated at a temperature of 25° C. for 2 hours. At the end of the reaction, 20% sodium hydroxide is added to neutralize the acidity of the medium induced by the sulfuric acid. The sulfate salt is separated by filtration.

[0232] The liquid obtained consists of methoxyethylformamide, toluene, methanol and by-products. The condenser of the reactor is replaced by a glass column 20 cm high filled with Propack type packing. The whole is placed under a vacuum of 10 mbar (1 bar = 0.1 MPa) and the reactor is heated to 60 ° C. The light product fraction is discarded and only the fraction corresponding to pure methoxyethylformamide is kept.

[0233] The pyrolyzer is equipped with a tube with a diameter of 10 mm and a length of 20 cm and is heated by an external electrical resistance. Methoxyethylformamide is charged into a jacketed reactor whose gas phase is connected to the inlet of the pyrolyzer. A glycol water condenser at 5 ° C is connected to the outlet of the pyrolyzer. The whole is placed under a vacuum of 90 mbar and the pyrolyzer is heated to a temperature of 430 ° C. The jacketed reactor is heated to a temperature of 150 ° C and the methoxyethylformamide is vaporized.

[0234] The pyrolysis gas is cooled by a condenser and collected in a glass flask. The resulting liquid is distilled by a rotary evaporator under reduced pressure to remove methanol. The N-vinylformamide remaining in the flask is weighed to determine the reaction yield relative to the starting formamide, and analyzed by liquid chromatography to determine the content of formamide and methoxyethylformamide impurities.

[0235] [Table 3]

[0236] Applicants have observed that the bio-derived nature of formamide allows for better conversion and generates fewer impurities.

[0237] Example 2 Synthesis of NVF using fossil-based FAM and partially renewable and non-fossil ACH. The origin of ACH and its 14 A series of tests were performed following the previously described protocol by adjusting the C percentage: CE2, where the ACH is of fossil origin, and Inv8–Inv14, where the ACH is of partially renewable and non-fossil origin (Table 4).

[0238] Acetaldehyde of non-fossil origin can be obtained from the processing of residues from the pulp and paper industry ("tall oil") to form bioethanol or bioethane precursors, or from agricultural waste, or from the processing of municipal waste, biomass, fermentation or recycling of carbon dioxide.

[0239] Various ACH 14 The proportion of C is determined according to standard ASTM D6866-21 method B as described above.

[0240] [Table 4]

[0241] Applicants have observed that the percentage of conversion of FAM is higher when the ACH is at least partially renewable and of non-fossil origin.

[0242] Example 3 Synthesis of NVF used according to the invention The origin of FAM and ACH (see Examples 1 and 2) and their 14 A series of tests were carried out according to the aforementioned protocol by adjusting the C percentage: comparative monomer CE3 and monomers according to the invention M1 to M7 (Table 5).

[0243] [Table 5]

[0244] The Applicant has observed that, according to the present invention, the use of a FAM which is partially or entirely renewable and non-fossil origin, and an ACH which is partially or entirely renewable and non-fossil origin, allows the process for obtaining NVF to be optimized.

[0245] II. Synthesis and Use of Biopolymers According to the Invention:

[0246] Example 4 Synthesis and biodegradability of polymers P1 to P4 according to the invention and comparative polymer CE4 (Table 6) 350 g of deionized water is added to a 1000 mL jacketed reactor equipped with a condenser and stirrer.

[0247] The pH is adjusted to 6.5 by adding 75% phosphoric acid diluted in water or 20% sodium hydroxide diluted in water.

[0248] The resulting solution is heated to 80° C. and bubbled with nitrogen for 30 minutes to remove all traces of dissolved oxygen.

[0249] The following is then added to the reactor: 120 g of N-vinylformamide obtained according to one of the previous examples are added continuously for 120 minutes. · At the same time, 0.54 g of 2,2'-azobis(2-methylpropionamidine) dihydrochloride dissolved in 7 g of water is also added continuously for 180 minutes.

[0250] After adding the above reagents, the reaction medium is maintained at 80° C. for 60 minutes, after which a viscous liquid is obtained.

[0251] 20 g of sodium bisulfite at a concentration of 40% are then added to the reaction medium, followed by 295 g of sodium hydroxide at 25% (wt % in water).

[0252] The hydrolysis of the polymer is thus carried out at 80° C. for 300 minutes.

[0253] The resulting product is cooled to 30° C. and 130 g of concentrated hydrochloric acid at 22% in water are added to neutralize the excess sodium hydroxide.

[0254] The biodegradability (after 28 days) of the obtained polymer is evaluated according to the OECD 302B standard (Table 6).

[0255] [Table 6]

[0256] The polymers P1 to P4 according to the invention, which are obtained partly or entirely from monomers of biological origin, are more readily biodegradable than the polymer CE4, which is obtained from fossil monomers.

[0257] Example 5 Use of the polymer according to the invention as an additive in papermaking processes. Retention agents are polymers that are added to cellulosic fiber pulp prior to the formation of paper to increase the retention efficiency of the paper.

[0258] Type of pulp used: Recycled fiber pulp The wet pulp is obtained by defibrating the dry pulp to obtain a final aqueous consistency of 1 wt %. The wet pulp is a pH neutral pulp made from 100% recycled cardboard fibers.

[0259] A / Drainage performance evaluation (DDA) The DDA ("Dynamic Drainage Analyzer") allows the automatic determination of the time (in seconds) required for the drainage of a fibrous suspension under vacuum. The polymer is added to the wet pulp (0.6 liters of 1.0 wt% pulp) in a cylinder of the DDA at 1000 rpm (revolutions per minute): T=0s: Pulp is stirred. T=20s: Add polymer T=30 s: Stop stirring and drain under vacuum at 200 mbar for 70 s.

[0260] The pressure under the canvas is recorded as a function of time. When all the water has been expelled from the fibrous mat, air passes through the mat and a discontinuity appears in the curve representing the pressure under the canvas as a function of time. The time recorded at this discontinuity, expressed in seconds, corresponds to the drainage time. The shorter the time, the better the vacuum drainage. The results obtained are shown in Figure 2 (vacuum drainage performance at 1 kg / mt and 1.5 kg / mt).

[0261] The polymers P1 to P4 according to the invention make it possible to obtain vacuum drainage performances which are significantly better than those of the CE4 polymer of fossil origin.

[0262] Performance when B / DSR is applied (dry strength), 90g.m -2 Grammage The paper is produced in an automatic dynamic form. First, a paper pulp is prepared by disintegrating 90 grams of virgin kraft fiber in 2 liters of hot water for 30 minutes. The resulting pulp is then diluted to a total volume of 9 liters. Once the consistency has been accurately measured, the required amount of this pulp is removed to finally obtain a sheet with a mass of 90 g / m2.

[0263] The pulp is then introduced into the vat of a dynamic sheet former and moderately agitated with a mechanical agitator to homogenize the fibrous suspension.

[0264] In manual mode, the circuit is primed by pumping the pulp to the height of the nozzle. After placing the blotter paper and the forming fabric in the bowl of the dynamic sheet former, the rotation of the bowl is started at 1000 m / min to build up the water wall. The various dry strength agents are introduced into the stirred fibrous suspension with a contact time of 30 to 45 seconds for each polymer. The sheet is produced by 22 strokes of the nozzle to project the pulp into the water wall (automatic mode). Once drained and the automatic sequence is completed, the forming fabric with the formed fiber network is removed from the bowl of the dynamic former and placed on a table. A dry blotter paper is laid on the wet fiber mat side and pressed once with a roller. The whole is turned over and the canvas is carefully separated from the fiber mat. A second sheet of dry blotter paper is placed and the sheet (between the two blotters) is pressed once with a press delivering 4 bar, before being dried in an airtight dryer at 117 ° C for 9 minutes. The two blotters are then removed and stored overnight in a humidity and temperature controlled room (50% relative humidity and 23° C.) The wet and dry strength properties of all sheets obtained by this procedure are evaluated as follows:

[0265] The burst (burst index) is measured on a Messmer Buchel M 405 burst tester according to the TAPPI T403 om-02 standard. The results are expressed in kPa. The burst index, expressed in kPa.m2 / g, is determined by dividing this value by the basis weight of the tested sheet. The results are expressed as a percentage improvement over the blank (Table 7).

[0266] Dry tensile strength is measured in the machine direction using a Testometric AX tensile device according to TAPPI T494 om-01. Measurements are expressed in km and as a percentage improvement over the blank (Table 7).

[0267] [Table 7]

[0268] The Applicant has observed that the polymers P1 to P4 according to the invention exhibit dry strength performance that is at least equal to or better than that of the comparative polymer CE4, in addition to better drainage performance.

Claims

1. A method for obtaining N-vinylformamide, comprising a reaction between acetaldehyde and formamide, at least one of which is at least partially renewable and non-fossil.

2. 2. The method of claim 1, wherein the acetaldehyde has a biogenic carbon content of 5 wt. % to 100 wt. % based on the total carbon mass in the acetaldehyde, the biogenic carbon content being measured according to standard ASTM D6866-21 method B.

3. 2. The method of claim 1, wherein the formamide has a biogenic carbon content of 5 wt. % to 100 wt. % relative to the total carbon mass in the formamide, the biogenic carbon content being measured according to standard ASTM D6866-21 method B.

4. 2. The method of claim 1, wherein the N-vinylformamide has a biobased carbon content of 5 wt. % to 100 wt. % based on the total carbon mass in the N-vinylformamide, the biobased carbon content being measured according to standard ASTM D6866-21 method B.

5. 2. The method according to claim 1, characterized in that the method is for obtaining N-vinylformamide by the alkoxy process, in which methanol is used as the protecting agent, and the method comprises thermolysis of N-methoxyethylformamide at a temperature between 200°C and 600°C and atmospheric pressure or partial vacuum.

6. Bio-derived N-vinylformamide having a bio-derived carbon content in the range of 5 wt% to 100 wt% based on the total carbon mass in the bio-derived N-vinylformamide, wherein the bio-derived carbon content is measured according to ASTM D6866-21 Method B.

7. 10. A method for obtaining a polymer by polymerization of at least one N-vinylformamide monomer obtainable according to the method of claim 1 or at least one bio-based N-vinylformamide monomer according to claim 6.

8. - at least a first monomer obtained by the method according to claim 1 or at least one bio-based N-vinylformamide according to claim 6, and - at least a second monomer different from the first monomer, said second monomer being selected from nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, monomers containing a hydrophobic moiety, and mixtures thereof; A method for obtaining a copolymer by polymerization of

9. - at least 5 mol % of a first monomer, said first monomer having a biobased carbon content of 5 wt % to 100 wt % relative to the total carbon mass in said N-vinylformamide, said biobased carbon content being measured according to standard ASTM D6866-21 method B; and - at least one second monomer containing at least 1% ethylenic unsaturation, said second monomer being different from the first monomer and having a biobased carbon content of 5 wt. % to 100 wt. % relative to the total carbon mass in said second monomer, said biobased carbon content being measured according to standard ASTM D6866-21 method B; 8. The method of claim 7, comprising:

10. The second monomer is selected from the group consisting of acrylamide, (meth)acrylic acid and / or salts thereof, 2-acrylamido-2-methylpropanesulfonic acid (ATBS) and / or salts thereof, N-vinylpyrrolidone (NVP), dimethylaminoethyl (meth)acrylate and its quaternized forms, dimethyldiallylammonium chloride (DADMAC), and methyl groups represented by the formula CH 2 =CHCO-NR 1 R 2 a substituted acrylamide having R 1 and R 2 are each independently a linear or branched carbon chain C n H 2n+1 9. The method according to claim 8, characterized in that the substituted acrylamide is selected from the group consisting of substituted acrylamides, wherein n ranges from 1 to 10.

11. 8. The method of claim 7, comprising a bio-based carbon content in the range of 5 wt. % to 100 wt. % based on the total carbon mass in the polymer, wherein the bio-based carbon content is measured according to ASTM D6866-21 Method B.

12. 8. A method for obtaining a polymer by partially or totally hydrolyzing the polymer obtained in claim 7 by acid or base hydrolysis to convert at least one N-vinylformamide monomer unit to N-vinylamine.

13. 8. Use of the polymer obtained according to claim 7 in a field selected from the following: hydrocarbon recovery, well drilling and cementing, hydrocarbon well stimulation, water treatment, treatment of fermentation slurries, treatment of sludge, papermaking, construction, wood processing, hydraulic composition processing, mining, cosmetic formulation, detergent formulation, textile manufacturing, battery component manufacturing, geothermal energy, sanitary napkin manufacturing, or agriculture.

14. 8. A method for making a sheet of paper or cardboard, wherein at least one polymer obtained according to claim 7 is added to a fiber suspension at one or more injection points before forming the sheet.

Images