METHOD FOR OBTAINING BIO-SOURCED N-VINYLFORMAMIDE

Abstract

A method for obtaining N-vinylformamide including the reaction between an acetaldehyde and a formamide, one of the two, preferably both, being at least partially renewable and non-fossil. A bio-sourced N-vinylformamide monomer, a bio-sourced polymer obtained by polymerization including at least N-vinylformamide monomer, and the use of the polymer in various technical fields.

Claims

1. A method for obtaining N-vinylformamide comprising reaction between an acetaldehyde and a formamide, wherein the acetaldehyde and/or the formamide being at least partially renewable and non-fossil.

2. The method according to claim 1, characterized in that the acetaldehyde has a bio-sourced carbon content of between 5 wt % and 100 wt % relative to the total carbon mass in said acetaldehyde, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B.

3. The method according to claim 1, characterized in that the formamide has a bio-sourced carbon content of between 5 wt % and 100 wt % relative to the total carbon mass in said formamide, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B.

4. The method according to claim 1, characterized in that the N-vinylformamide has a bio-sourced carbon content of between 5 wt % and 100 wt % relative to the total carbon mass in said N-vinylformamide, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B.

5. The method according to claim 1, characterized in that the method is a method for obtaining N-vinylformamide by the alkoxy process, methanol being used as protective agent, said method comprising thermal decomposition of N-methoxyethylformamide at a temperature between 200? ? C. and 600? C. and at atmospheric pressure or under a partial vacuum.

6. (canceled)

7. (canceled)

8. A bio-sourced-N-vinylformamide with a bio-sourced carbon content ranging between 5 wt % and 100 wt % relative to the total carbon mass in said monomer, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B.

9. A bio-sourced-N-vinylformamide obtained by reaction between an acetaldehyde and a formamide, said acetaldehyde and/or said formamide having a bio-sourced carbon content of between 5 wt % and 100 wt %, based on the total mass of carbon in said acetaldehyde and/or said formamide, respectively, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B.

10. A polymer obtained by polymerization of at least one N-vinylformamide monomer obtained according to the method according to claim 1.

11. (canceled)

12. The polymer according to claim 10, characterized in that the polymer is a copolymer with: at least a first monomer obtained by the method according to claim 1; and at least a second monomer different from the first monomer, wherein said second monomer is selected from the group consisting of nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, monomers comprising a hydrophobic moiety, and mixtures thereof.

13. The polymer according to claim 10, characterized in that the polymer comprises: at least 5 mol %, preferably at least 10 mol %, preferentially between 20 mol % and 99 mol %, more preferentially between 30 mol % and 90 mol % of a first monomer, said first monomer having a bio-sourced carbon content of between 5 wt % and 100 wt % relative to the total carbon mass in said N-vinylformamide, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B, and at least 1%, preferentially between 5% and 95%, more preferentially between 10% and 80% of at least one second monomer comprising an ethylenic unsaturation, said second monomer being different from the first monomer, and comprising a bio-sourced carbon content of between 5 wt % and 100 wt % relative to the total carbon mass in said second monomer, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B.

14. The polymer according to claim 12, characterized in that the second monomer is chosen from acrylamide, (meth)acrylic acid and/or a salt thereof, 2-acrylamido-2-methylpropane sulfonic acid (ATBS) and/or a salt thereof, N-vinylpyrrolidone (NVP), dimethylaminoethyl (meth)acrylate and quaternized versions thereof, dimethyldiallylammonium chloride (DADMAC), or a substituted acrylamide with the formula CH.sub.2?CHCONR.sup.1R.sup.2, R.sup.1 and R.sup.2 each independently being a linear or branched carbon chain C.sub.nH.sub.2n+1, wherein n ranges between 1 and 10.

15. The polymer according to claim 10, comprising a bio-sourced carbon content ranging between 5 wt % and 100 wt % relative to the total carbon mass in said polymer, the bio-sourced carbon content being measured according to a standard ASTM D6866-21 Method B.

16. A polymer obtained by partially or totally hydrolyzing, by acid or basic hydrolysis, the polymer according to claim 10, in order to convert at least one N-vinylformamide monomer unit into N-vinylamine.

17. (canceled)

18. (canceled)

19. (canceled)

20. (canceled)

21. (canceled)

22. (canceled)

23. A method for making a sheet of paper, cardboard or the like, whereby, before forming said sheet, at least one polymer is added to a fiber suspension at one or more injection points according to claim 10.

24. (canceled)

25. (canceled)

26. (canceled)

27. (canceled)

Description

FIGURES

[0248] FIG. 1 shows NVF formation from acetaldehyde and formamide.

[0249] FIG. 2 shows vacuum drainage performance at 1 kg/mt and 1.5 kg/mt.

EXAMPLES

[0250] The following examples relate to the synthesis of a bio-sourced N-vinylformamide according to the invention (hereinafter abbreviated NVF), comprising the reaction between an acetaldehyde (hereinafter abbreviated ACH), and a formamide (hereinafter abbreviated FAM), one of the two, preferably both, being at least partly of renewable and non-fossil origin (see FIG. 1). They also relate to the synthesis and the use of a bio-sourced polymer obtained from at least one bio-sourced N-vinylformamide monomer according to the invention.

[0251] The following examples serve to best illustrate the advantages of the invention.

Description of Purity Test.

[0252] The synthesis of NVF takes place in two steps, with first obtaining hydroxyethylformamide from acetaldehyde and formamide. The hydroxyethylformamide is then transformed into methoxyethylformamide (hereinafter abbreviated MEF) by reaction with methanol and a catalyst. The methoxyethylformamide is then pyrolyzed at high temperature in order to obtain N-vinylformamide.

[0253] The purity of the NVF is determined by high performance liquid chromatography, according to the following analysis conditions (Table 2):

TABLE-US-00002 TABLE 2 From 0 to 9 minutes: 99% water weight + 1% acetonitrile weight From 9 to 17 minutes: 80% water weight + 20% Mobile phase gradient acetonitrile weight Injection volume 10 ?L Column temperature 40? C. Injection rate 0.5 mL/min Detection wavelength 200 nm Analysis time: 17 minutes Features of the HPLC Column filled with C.sub.18silica, Zorbax Eclipse column Plus C18 RRHT type, with a diameter of 3 mm. a length of 150 mm, and containing particles having a size of 1.8 ?m

[0254] Using these conditions, and by measuring the areas of the various impurity peaks, the purity of NVF can be calculated.

[0255] The quantification of formamide and methoxyethylformamide is carried out via a calibration of standards.

[0256] The retention time of formamide is 1.43 minutes and that of methoxyethylformamide is 4.5 minutes.

I. Synthesis of Partially Bio-Sourced NVF

Example 1: Synthesis of NVF with FAM Partly of Renewable and Non-Fossil Origin and ACH of Fossil Origin

[0257] A set of tests was carried out by varying the origin of the formamide and its percentage in .sup.14C: FAM of fossil origin CE 1 and FAM partly of renewable and non-fossil origin Inv 1 to Inv 7 (Table 3).

[0258] The levels of .sup.14C are measured according to the ASTM D6866-21 standard, method B. This standard makes it possible to characterize the bio-sourced nature of a chemical compound by determining the bio-sourced carbon level of said compound.

[0259] A zero wt % .sup.14C represents the total absence of measurable .sup.14C in a material, thus indicating a fossil carbon source.

[0260] As indicated in Table 3, formamide of non-fossil origin comes from various sources, such as the treatment of residues from the paper pulp industry (tall oil), or agricultural waste in order to form the precursor formic acid (via bio-methanol) or ethyl formate (via bio-ethane), or from the treatment of municipal waste, biomass, or fermentation or recycling of carbon dioxide, or even the amino portion of formamide can be derived from green ammonia.

[0261] The procedure was carried out as follows for each test: 800 g of toluene are added to a 2 000 mL reactor equipped with a jacket, a stirrer and a condenser.

[0262] The reactor is degassed with nitrogen in order to drive out the air present therein.

[0263] The reactor is maintained at a temperature of 20? C., in order to be able to introduce 235 g of acetaldehyde therein.

[0264] A casting funnel is loaded with 200 g of formamide containing 1.33 g of potassium bicarbonate.

[0265] 20% of the contents of the dropping funnel feeds the reactor over a period of 30 minutes, while maintaining the reaction medium at 20? ? C., 0.5 g of hydroxyethylformamide crystals are then added to the reaction medium as crystallization seed. After a waiting time of 30 minutes, the remaining quantity of formamide and potassium bicarbonate contained in the dropping funnel are added to the reaction medium for a period of 3 hours. The temperature is maintained at 20? C. throughout the reaction in order to prevent the loss of acetaldehyde by evaporation.

[0266] The hydroxyethylformamide obtained is a white solid suspended in toluene, which is separated by Buchner filtration. The solid obtained is again introduced into the reactor and then 430 g of methanol and 3.5 g of 98% concentrated sulfuric acid in water are added. The mixture is heated at a temperature of 25? C. for 2 hours. At the end of this reaction, 20% sodium hydroxide is added in order to neutralize the acidity of the medium induced by the sulfuric acid. Sulfate salts are separated by filtration.

[0267] The liquid obtained is composed of methoxyethylformamide, toluene, methanol and by-products. The reactor condenser is replaced by a 20 cm high glass column filled with Propack type packing. The whole is placed under a vacuum of 10 mbar (1 bar=0.1 MPa) and the reactor heated to 60? C. The light product fractions are discarded and only the fraction corresponding to pure methoxyethylformamide is retained.

[0268] A pyrolyzer is equipped with a tube of 10 mm in diameter and a length of 20 cm, and heated by an external electrical resistance. The methoxyethylformamide is loaded into a jacketed reactor which is connected for the gas phase to the inlet of the pyrolyzer. A 5? glycol water condenser is connected to the outlet of the pyrolyser. The whole is placed under a vacuum of 90 mbar, the pyrolyser being heated to a temperature of 430? C. The jacketed reactor is heated to a temperature of 150? C. in order to vaporize the methoxyethylformamide.

[0269] The pyrolysis gases are cooled by the condenser and collected in a glass flask. The liquid obtained is distilled with a rotary evaporator under a reduced vacuum in order to eliminate the methanol. The remaining N-vinylformamide in the flask is weighed to determine the yield of the reaction relative to the starting formamide, and is analysed by liquid chromatography to determine the content of formamide and methoxyethylformamide impurities.

TABLE-US-00003 TABLE 3 FAM in MEF in wt % NVF obtained Origin .sup.14C of % FAM obtained NVF FAM FAM conversion (%) (%) CE 1 Fossil 0 78 2.6 4.2 Inv 1 Bio-ethane 40 79 2.2 3.7 (agricultural waste) Inv 2 CO.sub.2 capture + 40 79 2.1 3.8 Green ammonia Inv 3 CO.sub.2 capture + 50 81 2 3.7 Green ammonia Inv 4 Bio-methanol 50 80 2.2 3.8 (agricultural waste) Inv 5 Bio-methanol 70 82 1.9 3 (biomass) + Green ammonia Inv 6 Bio-methanol 80 84 1.6 2.9 (biomass) + Green ammonia Inv 7 Bio-methanol 100 86 1.4 1.8 (agricultural waste) + Green ammonia (CE = counter-example; Inv = example according to the invention)

[0270] The Applicant has observed that the bio-sourced nature of formamide allows better conversion, and generates fewer impurities.

Example 2: Synthesis of NVF with Fossil-Based FAM and Partly Renewable and Non-Fossil ACH

[0271] A set of tests was carried out according to the protocol previously described by adjusting the origin of the ACH and its percentage of .sup.14C: ACH of fossil origin CE 2 and ACH partly of renewable and non-fossil origin Inv 8 to Inv 14 (Table 4).

[0272] Acetaldehyde of non-fossil origin comes from the treatment of residues from the paper pulp industry (tall oil), or from agricultural waste in order to form the bioethanol or bio-ethane precursor, or from the of treatment municipal waste, biomass, or carbon dioxide fermentation or recycling.

[0273] The rate of .sup.14C in the various ACH is measured, as previously, according to standard ASTM D6866-21 method B.

TABLE-US-00004 TABLE 4 FAM in MEF in NVF obtained wt % .sup.14C % FAM obtained NVF ACH origin of FAM conversion (%) (%) CE 2 Fossil 0 77 2.5 4.1 Inv 8 Bioethane 40 78 2.1 3.8 (biomass) Inv 9 Bioethane 50 81 1.9 3.6 (biomass) Inv 10 Bioethanol 40 79 2.3 3.8 (agricultural waste) Inv 11 Bioethanol 50 81 2 3.5 (agricultural waste) Inv 12 Bioethanol 70 82 1.6 2.8 (agricultural waste) Inv 13 Bioethanol 80 83.5 1.3 2.5 (agricultural waste) Inv 14 Bioethanol 100 87 1.2 1.7 (agricultural waste) (CE = counter-example; Inv = example according to the invention)

[0274] The applicant has observed that the percentage of conversion of FAM is greater when the ACH is at least partly of renewable and non-fossil origin.

Example 3: Synthesis of NVF Used According to the Invention

[0275] A set of tests was carried out according to the protocol previously described by adjusting the origin of the FAM and the ACH (cf examples 1 and 2) and their percentages of .sup.14C: comparative monomer CE 3 and monomers according to the invention M1 to M7 (Table 5).

TABLE-US-00005 TABLE 5 Monomers CE 3 M1 M2 M3 M4 M5 M6 M7 FAM origin CE 1 Inv 2 Inv 3 Inv 1 Inv 4 Inv 5 Inv 6 Inv 7 ACH origin CE 2 Inv 8 Inv 9 Inv 10 Inv 11 Inv 12 Inv 13 Inv 14 % FAM 78 80 82 79 80 82 85 88 conversion FAM in NVF 2.5 2 1.9 2.1 2 1.5 1 0.9 obtained (%) MEF in the 4 3.7 3.6 3.5 3.7 2.1 1.8 1.2 NVF obtained (%) (CE = counter-example; Inv = example according to the invention)

[0276] The applicant observes that the use of FAM partially or totally of renewable and non-fossil origin, and of ACH partially or totally of renewable and non-fossil origin, according to the invention, makes it possible to optimize the process for obtaining NVF.

II. Synthesis and Use of Bio-Sourced Polymer According to the Invention:

Example 4: Synthesis and Biodegradability of Polymers P1 to P4 According to the Invention and of a Comparative Polymer CE 4 (Table 6)

[0277] 350 g of deionised water is added to a 1 000 mL jacketed reactor, equipped with a condenser and a stirrer.

[0278] The pH is adjusted to 6.5 by adding 75% phosphoric acid diluted in water or 20% sodium hydroxide diluted in water.

[0279] The solution thus obtained is heated to 80? C., bubbling with nitrogen is carried out for 30 minutes in order to eliminate all traces of dissolved oxygen.

[0280] The following are then added to the reactor: [0281] 120 g of N-vinylformamide obtained according to one of the preceding examples are added continuously for 120 minutes. [0282] Concomitantly, 0.54 g of 2,2-Azobis(2-methylpropionamidine) dihydrochloride dissolved in 7 g of water is also added continuously for 180 minutes.

[0283] After the addition of the above reagents, the reaction medium is maintained at 80? C for 60 minutes. A viscous liquid is then obtained.

[0284] 20 g of sodium bisulphite at 40% concentration, followed by 295 g of 25% sodium hydroxide are then added to the reaction medium (wt % in water).

[0285] The hydrolysis of the polymer is thus carried out for 300 minutes at 80? C.

[0286] The product obtained is cooled to 30? C. then 130 g of 22% concentrated hydrochloric acid in water are added to neutralize the excess sodium hydroxide.

[0287] The biodegradability (after 28 days) of the polymers obtained is evaluated according to the OECD 302B standard (Table 6).

TABLE-US-00006 TABLE 6 Polymer P1 P2 P3 P4 CE4 Mass of NVF (g) 120 120 120 120 120 Monomers Inv 7 CE 1 M7 M6 CE 3 CE 2 Inv 14 wt % .sup.14C of FAM 100 0 100 80 0 wt % .sup.14C of ACH 0 100 100 80 0 wt % .sup.14C of NVF 33 67 100 80 0 % biodegradability 15 26 40 33 5 (CE = counter-example)

[0288] The polymers P1 to P4 according to the invention, obtained from partially or totally bio-sourced monomers are more easily biodegradable than the polymer CE 4 obtained from fossil monomers.

Example 5: Use of a Polymer According to the Invention as an Additive in a Papermaking Process

[0289] Retention agents are polymers added to cellulose fibre pulps prior to paper formation to increase the retention efficiency of the paper.

Types of Pulp Used: Recycled Fiber Pulp

[0290] The wet pulp is obtained by disintegrating dry pulp in order to obtain a final aqueous concentration of 1 wt %. It is a pH-neutral pulp made from 100% recycled cardboard fibres.

A/Evaluation of Drainage Performance (DDA)

[0291] The DDA (Dynamic Drainage Analyzer) makes it possible to automatically determine the time (in seconds) required to drain a fibrous suspension under vacuum. The polymers are added to the wet pulp (0.6 liters of pulp at 1.0 wt %) in the cylinder of the DDA at 1000 rpm (revolutions per minute): [0292] T=0 s: stirring the pulp [0293] T=20 s: Addition of polymer [0294] T=30 s: stirring stopped and draining under vacuum at 200 mbar for 70 seconds.

[0295] The pressure under the canvas is recorded as a function of time. When all the water is evacuated from the fibrous mat, the air passes through it causing a break in slope to appear on the curve representing the pressure under the canvas as a function of time. The time recorded at this break in slope, expressed in seconds, corresponds to the draining time. The shorter the time, the better the vacuum drainage. The results obtained are shown in FIG. 2 (Vacuum drainage performance at 1 kg/mt and 1.5 kg/mt).

[0296] The polymers according to the invention P1 to P4 make it possible to obtain significantly better vacuum drainage performance than that of the CE4 polymer of fossil origin.

B/Performance in DSR Application (Dry Strength), Grammage at 90 g.Math.m.sup.?2

[0297] The paper forms are made with an automatic dynamic form. First, the paper pulp is prepared by disintegrating 90 grams of virgin kraft fibers in 2 liters of hot water for 30 minutes. The pulp obtained is then diluted to a total volume of 9 liters. Once the consistency has been precisely measured, the necessary quantity of this pulp is removed so as to obtain, in the end, a sheet with a weight of 90 g/m2.

[0298] The pulp is then introduced into the vat of the dynamic sheet former and is stirred moderately with a mechanical stirrer in order to homogenize the fibrous suspension.

[0299] In manual mode, the pulp is pumped up to the level of the nozzle in order to prime the circuit. A blotter and the forming cloth are placed in the bowl of the dynamic sheet former before starting the rotation of the bowl at 1000 m/min and building the water wall. Various dry strength agents are then introduced into the stirred fibrous suspension with a contact time of 30 to 45 seconds for each polymer. The sheet is then produced (in automatic mode) by 22 round trips of the nozzle projecting the pulp into the wall of water. Once the water is drained and the automatic sequence is complete, 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 is laid on the side of the wet fiber mat and is pressed once with a roller. The whole is turned over and the canvas is delicately separated from the fibrous mattress. A second dry blotter is placed and the sheet (between the two blotters) is pressed once under a press delivering 4 bars and is then dried on a tense dryer for 9 min at 117? C. The two blotters are then removed and the sheet is stored overnight in a room with controlled humidity and temperature (50% relative humidity and 23? C.). The wet and dry strength properties of all sheets obtained by this procedure are then evaluated as follows.

[0300] The burst (Burst index) is measured with a Messmer Buchel M 405 burst tester according to the TAPPI T403 om-02 standard. The result is expressed in kPa. The bursting index, expressed in kPa.Math.m2/g, is determined by dividing this value by the basis weight of the sheet tested. Results are expressed as percent improvement over blank (Table 7).

[0301] Dry tensile strength is measured in the machine direction with a Testometric AX tensile device according to TAPPI T494 om-01. The measurement is expressed in km, and is expressed as a percentage improvement over blank (Table 7).

TABLE-US-00007 TABLE 7 Dry traction (breaking length) Burst Index (km) Polymer dosage Polymer dosage Polymer 1 kg/mt 1.5 kg/mt 1 kg/mt 1.5 kg/mt CE4 17 21 24 21 P1 20 24 31 23 P2 22 26 34 23 P3 23 27 37 24 P4 24 27 40 25 (CE = counter-example)

[0302] The applicant observes that in addition to better drainage performance, polymers P1 to P4 according to the invention exhibit dry strength performance at least equivalent or even better than that of the comparative polymer CE4.