A preparation method of a pulp papermaking aid

Abstract

The present invention discloses a preparation method of a pulp papermaking aid. Using corn starch and cellulose as raw materials, acrylamide and methacryloyloxyethyl trimethyl ammonium chloride are added, and under the action of an initiator, polymerization grafting is carried out to graft and compound the corn starch and cellulose to obtain a composite emulsion. A strengthening aid is added to the composite emulsion. After the isocyanate group on the strengthening aid reacts with the hydroxyl group or amino group in the composite emulsion, adipic dihydrazide is added and mixed evenly to prepare the pulp papermaking aid; the strengthening aid has a hyperbranched structure, and the branched chains have organosilicon segments, and the side chains contain long fluorine chains and carbon chains, so that the strengthening aid has a good hydrophobic effect, and the ketone carbonyl group in the hydrophobic group can crosslink with the hydrazide group in adipic dihydrazide to form a dense hydrophobic film on the paper surface, and cooperate with cellulose and starch to further improve the mechanical properties of the paper.

Description

Technical Field

[0001] The present invention relates to the technical field of papermaking, and particularly relates to a preparation method of a pulp papermaking aid. Background Art

[0002] With the continuous development of the papermaking industry, the uses of paper have developed from aspects of cultural life such as writing and printing to all fields of human life. Paper and paperboard are not only carriers of human culture and information, but also important materials in aspects such as industry, agriculture, science, life, and hygiene; it has a close connection with industrial and agricultural production and all sectors of the national economy, and has become the basis of the material civilization and spiritual civilization of human society. Papermaking wet-end chemistry is a discipline that discusses the reaction and interaction laws among various components in papermaking pulp, such as fibers, water, fillers, chemical aids, etc., during the processes of water filtration, retention, forming, and white water circulation in the papermaking machine wire section. The papermaking practice experiences at home and abroad have proved that the application of various chemical aids in the papermaking production process can achieve twice the result with half the effort, so it has been increasingly favored by various papermaking manufacturers, and the theory and application of papermaking wet-end chemistry have developed rapidly. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation method of a pulp papermaking aid, which solves the problems of low strength and poor water resistance of paper at the present stage.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A preparation method of a pulp papermaking aid specifically includes the following steps:

[0006] Step S1: Disperse corn starch and cellulose in deionized water, add acrylamide, methacryloyloxyethyl trimethyl ammonium chloride, and propylene glycol methyl ether, and under the conditions of a rotation speed of 200 - 300 r / min and a temperature of 80 - 90 °C, stir and add ammonium persulfate, and react for 3 - 5 h to obtain a composite emulsion;

[0007] Step S2: Under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 60 - 70 °C, stir the composite emulsion and add a strengthening aid and dibutyltin dilaurate, and after reacting for 4 - 6 h, add adipic dihydrazide and mix evenly to obtain a pulp papermaking aid.

[0008] Further, the dosage ratio of the corn starch, cellulose, deionized water, acrylamide, methacryloyloxyethyl trimethyl ammonium chloride, and propylene glycol methyl ether in step S1 is 1.5 g:1 g:10 mL:0.6 g:0.13 g:0.01 g.

[0009] Further, the dosage ratio of the composite emulsion and the strengthening agent described in step S2 is 25 mL: 2 g, the dosage of dibutyltin dilaurate is 4-6% of the mass of the strengthening agent, and the dosage of adipic dihydrazide is 1-3%.

[0010] Further, the strengthening agent is prepared by the following steps:

[0011] Mix the modified monomer and castor oil, and under the conditions of a rotation speed of 300-500 r / min and a temperature of 60-70 °C, stir and add diphenylmethane diisocyanate, react for 5-10 min, then raise the temperature to 80-85 °C, and continue to react for 1-1.5 h to obtain the strengthening agent.

[0012] Further, the molar ratio of the modified monomer, castor oil and diphenylmethane diisocyanate is n: 2n + 1: 4n + 2, where n is a natural number greater than 0.

[0013] Further, the modified monomer is prepared by the following steps:

[0014] Step A1: Mix dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane, dimethyldichlorosilane and deionized water evenly, under the conditions of a rotation speed of 200-300 r / min and a temperature of 25-30 °C, stir for 20-30 min, then add tetrahydrofuran and concentrated sulfuric acid, raise the temperature to 55-65 °C, keep warm for 5-10 min, add 1,1,3,3-tetramethyldisiloxane, and react for 3-5 h to obtain intermediate 1;

[0015] Step A2: Mix acrylic acid, diethanolamine, 1-hydroxybenzotriazole and tetrahydrofuran evenly, and under the conditions of a rotation speed of 200-300 r / min and a temperature of 30-40 °C, react for 3-5 h to obtain intermediate 2. Mix intermediate 2, epichlorohydrin, benzyltrimethylammonium bromide and toluene evenly, and under the conditions of a rotation speed of 150-200 r / min and a temperature of 100-105 °C, react for 3-5 h, then cool down to 70-75 °C, add sodium hydroxide solution, and react for 5-7 h to obtain intermediate 3;

[0016] Step A3: Mix intermediate 3, intermediate 1 and toluene evenly, introduce nitrogen protection, under the conditions of a rotation speed of 200-300 r / min and a temperature of 50-60 °C, stir and add chloroplatinic acid, react for 6-8 h, then raise the temperature to 100-110 °C, add levulinic acid and triphenylphosphine, react for 1-1.5 h, then raise the temperature to 120-125 °C, and react until the acid value is less than 10 mg / g to obtain the modified monomer.

[0017] Further, the dosage ratio of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane, deionized water and 1,1,3,3-tetramethyldisiloxane described in step A1 is 2 mmol: 3 mmol: 5 mmol: 5 mL: 3 mmol, and the dosage of concentrated sulfuric acid is 3-5% of the total mass of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane and 1,1,3,3-tetramethyldisiloxane.

[0018] Further, the molar ratio of acrylic acid, diethanolamine and 1-hydroxybenzotriazole described in step A2 is 1:1:1.1, the molar ratio of intermediate 1, epichlorohydrin and sodium hydroxide is 1:2:3, the mass fraction of the sodium hydroxide solution is 30%, and the dosage of benzyltrimethylammonium bromide is 2% of the total mass of intermediate 1 and epichlorohydrin.

[0019] Further, the molar ratio of intermediate 3, intermediate 1 and levulinic acid described in step A3 is 2:1:4, the dosage of chloroplatinic acid is 0.01‰ of the total mass of intermediate 1 and intermediate 3, and the dosage of triphenylphosphine is 0.01‰ of the mass of levulinic acid.

[0020] Advantages of the present invention: A pulp papermaking aid prepared by the present invention uses corn starch and cellulose as raw materials, adds acrylamide and methacryloyloxyethyl trimethyl ammonium chloride, and under the action of an initiator, polymerizes and grafts to graft and compound corn starch and cellulose to obtain a composite emulsion. Adding a strengthening aid to the composite emulsion, after the isocyanate group on the strengthening aid reacts with the hydroxyl group or amino group in the composite emulsion, adipic dihydrazide is added and mixed evenly to prepare the pulp papermaking aid. The strengthening aid is prepared by reacting a modified monomer, castor oil and diphenylmethane diisocyanate, and through dosage control, a polyurethane prepolymer is formed. The modified monomer is hydrolyzed with dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane and dimethyldichlorosilane as raw materials, and then polymerized with 1,1,3,3-tetramethyldisiloxane to form an intermediate 1 capped with Si-H bonds. Acrylic acid and diethanolamine are dehydrated and condensed under the action of 1-hydroxybenzotriazole, so that the carboxyl group on acrylic acid and the imine on diethanolamine are dehydrated and condensed to prepare intermediate 2. Intermediate 2 and epichlorohydrin are reacted, so that the alcohol hydroxyl group on intermediate 2 reacts with the epoxy group on epichlorohydrin, and then cyclized under the action of a sodium hydroxide solution to prepare intermediate 3. Intermediate 3 and intermediate 1 are reacted, so that the double bond on intermediate 3 reacts with the Si-H bond on intermediate 1, and then levulinic acid and triphenylphosphine are added. The carboxyl group on levulinic acid will react with the epoxy group under the action of triphenylphosphine to generate an alcohol hydroxyl group to prepare the modified monomer. The strengthening aid has a hyperbranched structure, and the branched chain has an organosilicon segment, and the side chain contains a long fluorine chain and a carbon chain, so that the strengthening aid has a good hydrophobic effect. And cellulose and starch contain a large number of hydrophilic groups and cations. When the papermaking aid is used, due to the presence of cations, the papermaking aid carries a positive charge and can bind to the negatively charged pulp fibers through electrostatic action, so that the hydrophobic groups are oriented outward of the paper, and the ketone carbonyl group in the hydrophobic groups can crosslink with the hydrazide group in adipic dihydrazide to form a dense hydrophobic film on the paper surface, and cooperate with cellulose and starch to further improve the mechanical properties of the paper. Detailed implementation mode

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] Example 1

[0023] A preparation method of a pulp papermaking aid specifically includes the following steps:

[0024] Step S1: Disperse corn starch and cellulose in deionized water, add acrylamide, methacryloyloxyethyl trimethyl ammonium chloride and propylene glycol methyl ether, stir and add ammonium persulfate under the conditions of a rotation speed of 200 r / min and a temperature of 80 °C, and react for 3 h to obtain a composite emulsion;

[0025] Step S2: Stir and add a strengthening aid and dibutyltin dilaurate to the composite emulsion under the conditions of a rotation speed of 150 r / min and a temperature of 60 °C, react for 4 h, then add adipic dihydrazide and mix evenly to obtain a pulp papermaking aid.

[0026] The dosage ratio of the corn starch, cellulose, deionized water, acrylamide, methacryloyloxyethyl trimethyl ammonium chloride and propylene glycol methyl ether described in Step S1 is 1.5 g: 1 g: 10 mL: 0.6 g: 0.13 g: 0.01 g.

[0027] The dosage ratio of the composite emulsion and the strengthening aid described in Step S2 is 25 mL: 2 g, the dosage of dibutyltin dilaurate is 4% of the mass of the strengthening aid, and the dosage of adipic dihydrazide is 1%.

[0028] The strengthening aid described above is prepared by the following steps:

[0029] Mix the modified monomer and castor oil, stir and add diphenylmethane diisocyanate under the conditions of a rotation speed of 300 r / min and a temperature of 60 °C, react for 5 min, then raise the temperature to 80 °C and continue to react for 1 h to obtain the strengthening aid.

[0030] The molar ratio of the modified monomer, castor oil and diphenylmethane diisocyanate is 1: 3: 6.

[0031] The modified monomer described above is prepared by the following steps:

[0032] Step A1: Mix dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane, dimethyldichlorosilane and deionized water evenly, stir for 20 min under the conditions of a rotation speed of 200 r / min and a temperature of 25 °C, then add tetrahydrofuran and concentrated sulfuric acid, raise the temperature to 55 °C, keep warm for 5 min, add 1,1,3,3 - tetramethyldisiloxane, and react for 3 h to obtain Intermediate 1;

[0033] Step A2: Mix acrylic acid, diethanolamine, 1-hydroxybenzotriazole, and tetrahydrofuran evenly. React for 3 h under the conditions of a rotation speed of 200 r / min and a temperature of 30 °C to obtain Intermediate 2. Mix Intermediate 2, epichlorohydrin, benzyltrimethylammonium bromide, and toluene evenly. After reacting for 3 h under the conditions of a rotation speed of 150 r / min and a temperature of 100 °C, cool down to 70 °C, add sodium hydroxide solution, and react for 5 h to obtain Intermediate 3;

[0034] Step A3: Mix Intermediate 3, Intermediate 1, and toluene evenly, introduce nitrogen for protection, stir and add chloroplatinic acid under the conditions of a rotation speed of 200 r / min and a temperature of 50 °C. After reacting for 6 h, raise the temperature to 100 °C, add levulinic acid and triphenylphosphine, react for 1 h, then raise the temperature to 120 °C and react until the acid value is less than 10 mg / g to obtain the modified monomer.

[0035] The dosage ratio of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane, deionized water, and 1,1,3,3-tetramethyldisiloxane described in Step A1 is 2 mmol:3 mmol:5 mmol:5 mL:3 mmol, and the dosage of concentrated sulfuric acid is 3% of the total mass of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane, and 1,1,3,3-tetramethyldisiloxane.

[0036] The molar ratio of acrylic acid, diethanolamine, and 1-hydroxybenzotriazole described in Step A2 is 1:1:1.1, the molar ratio of Intermediate 1, epichlorohydrin, and sodium hydroxide is 1:2:3, the mass fraction of the sodium hydroxide solution is 30%, and the dosage of benzyltrimethylammonium bromide is 2% of the total mass of Intermediate 1 and epichlorohydrin. [[ID=E11]]

[0037] The molar ratio of Intermediate 3, Intermediate 1, and levulinic acid described in Step A3 is 2:1:4, the dosage of chloroplatinic acid is 0.01‰ of the total mass of Intermediate 1 and Intermediate 3, and the dosage of triphenylphosphine is 0.01‰ of the mass of levulinic acid.

[0038] Example 2

[0039] A preparation method of a pulp papermaking aid, specifically including the following steps:

[0040] Step S1: Disperse corn starch and cellulose in deionized water, add acrylamide, methacryloyloxyethyltrimethylammonium chloride, and propylene glycol methyl ether, stir and add ammonium persulfate under the conditions of a rotation speed of 200 r / min and a temperature of 85 °C, and react for 4 h to obtain a composite emulsion;

[0041] Step S2: Stir and add a strengthening aid and dibutyltin dilaurate to the composite emulsion under the conditions of a rotation speed of 150 r / min and a temperature of 65 °C, react for 5 h, then add adipic dihydrazide and mix evenly to obtain a pulp papermaking aid.

[0042] The dosage ratio of the corn starch, cellulose, deionized water, acrylamide, methylacryloyloxyethyl trimethyl ammonium chloride, and propylene glycol methyl ether described in Step S1 is 1.5 g: 1 g: 10 mL: 0.6 g: 0.13 g: 0.01 g.

[0043] The dosage ratio of the composite emulsion and the strengthening aid described in Step S2 is 25 mL: 2 g, the dosage of dibutyltin dilaurate is 5% of the mass of the strengthening aid, and the dosage of adipic dihydrazide is 2%.

[0044] The strengthening aid is prepared by the following steps:

[0045] Mix the modified monomer and castor oil, stir and add diphenylmethane diisocyanate under the conditions of a rotation speed of 300 r / min and a temperature of 65 °C, react for 8 min, then raise the temperature to 83 °C and continue to react for 1.5 h to obtain the strengthening aid.

[0046] The molar ratio of the modified monomer, castor oil, and diphenylmethane diisocyanate is 2: 5: 10.

[0047] The modified monomer is prepared by the following steps:

[0048] Step A1: Mix dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane, dimethyldichlorosilane, and deionized water evenly, stir for 25 min under the conditions of a rotation speed of 200 r / min and a temperature of 30 °C, then add tetrahydrofuran and concentrated sulfuric acid, raise the temperature to 60 °C, keep warm for 8 min, add 1,1,3,3 - tetramethyldisiloxane, and react for 4 h to obtain Intermediate 1;

[0049] Step A2: Mix acrylic acid, diethanolamine, 1 - hydroxybenzotriazole, and tetrahydrofuran evenly, react for 4 h under the conditions of a rotation speed of 200 r / min and a temperature of 35 °C to obtain Intermediate 2. Mix Intermediate 2, epichlorohydrin, benzyltrimethylammonium bromide, and toluene evenly, react for 4 h under the conditions of a rotation speed of 150 r / min and a temperature of 100 °C, then cool down to 73 °C, add sodium hydroxide solution, and react for 6 h to obtain Intermediate 3;

[0050] Step A3: Mix intermediate 3, intermediate 1, and toluene evenly, introduce nitrogen for protection, stir and add chloroplatinic acid under the conditions of a rotation speed of 200 r / min and a temperature of 55 °C, react for 7 h, then raise the temperature to 105 °C, add levulinic acid and triphenylphosphine, react for 1.3 h, then raise the temperature to 123 °C, and continue the reaction until the acid value is less than 10 mg / g to obtain the modified monomer.

[0051] The dosage ratio of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane, deionized water, and 1,1,3,3 - tetramethyldisiloxane described in Step A1 is 2 mmol: 3 mmol: 5 mmol: 5 mL: 3 mmol, and the dosage of concentrated sulfuric acid is 4% of the total mass of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane, and 1,1,3,3 - tetramethyldisiloxane.

[0052] The molar ratio of acrylic acid, diethanolamine, and 1 - hydroxybenzotriazole described in Step A2 is 1:1:1.1, the molar ratio of intermediate 1, epichlorohydrin, and sodium hydroxide is 1:2:3, the mass fraction of the sodium hydroxide solution is 30%, and the dosage of benzyltrimethylammonium bromide is 2% of the total mass of intermediate 1 and epichlorohydrin.

[0053] The molar ratio of intermediate 3, intermediate 1, and levulinic acid described in Step A3 is 2:1:4, the dosage of chloroplatinic acid is 0.01‰ of the total mass of intermediate 1 and intermediate 3, and the dosage of triphenylphosphine is 0.01‰ of the mass of levulinic acid.

[0054] Example 3

[0055] A preparation method of a pulp papermaking aid, specifically including the following steps:

[0056] Step S1: Disperse corn starch and cellulose in deionized water, add acrylamide, methacryloyloxyethyltrimethylammonium chloride, and propylene glycol methyl ether, stir and add ammonium persulfate under the conditions of a rotation speed of 300 r / min and a temperature of 90 °C, and react for 5 h to obtain a composite emulsion;

[0057] Step S2: Stir and add a strengthening aid and dibutyltin dilaurate to the composite emulsion under the conditions of a rotation speed of 200 r / min and a temperature of 70 °C, react for 6 h, then add adipic dihydrazide and mix evenly to obtain the pulp papermaking aid.

[0058] The dosage ratio of corn starch, cellulose, deionized water, acrylamide, methacryloyloxyethyltrimethylammonium chloride, and propylene glycol methyl ether described in Step S1 is 1.5 g: 1 g: 10 mL: 0.6 g: 0.13 g: 0.01 g.

[0059] The dosage ratio of the composite emulsion and the strengthening aid described in step S2 is 25 mL: 2 g, the dosage of dibutyltin dilaurate is 6% of the mass of the strengthening aid, and the dosage of adipic dihydrazide is 3%.

[0060] The strengthening aid described above is prepared by the following steps:

[0061] Mix the modified monomer and castor oil, and under the conditions of a rotation speed of 500 r / min and a temperature of 70 °C, stir and add diphenylmethane diisocyanate, react for 10 min, then raise the temperature to 85 °C, and continue to react for 1.5 h to obtain the strengthening aid.

[0062] The molar ratio of the modified monomer, castor oil, and diphenylmethane diisocyanate is 3:7:14.

[0063] The modified monomer is prepared by the following steps:

[0064] Step A1: Mix dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane, dimethyldichlorosilane, and deionized water evenly. Under the conditions of a rotation speed of 300 r / min and a temperature of 30 °C, stir for 30 min, then add tetrahydrofuran and concentrated sulfuric acid, raise the temperature to 65 °C, keep warm for 10 min, add 1,1,3,3 - tetramethyldisiloxane, and react for 5 h to obtain intermediate 1;

[0065] Step A2: Mix acrylic acid, diethanolamine, 1 - hydroxybenzotriazole, and tetrahydrofuran evenly. Under the conditions of a rotation speed of 300 r / min and a temperature of 40 °C, react for 5 h to obtain intermediate 2. Mix intermediate 2, epichlorohydrin, benzyltrimethylammonium bromide, and toluene evenly. Under the conditions of a rotation speed of 200 r / min and a temperature of 105 °C, react for 5 h, then cool down to 75 °C, add sodium hydroxide solution, and react for 7 h to obtain intermediate 3;

[0066] Step A3: Mix intermediate 3, intermediate 1, and toluene evenly, introduce nitrogen for protection. Under the conditions of a rotation speed of 300 r / min and a temperature of 60 °C, stir and add chloroplatinic acid, react for 8 h, then raise the temperature to 110 °C, add levulinic acid and triphenylphosphine, react for 1.5 h, raise the temperature to 125 °C, and react until the acid value is less than 10 mg / g to obtain the modified monomer.

[0067] The amount ratio of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane, deionized water and 1,1,3,3-tetramethyldisiloxane described in step A1 is 2mmol:3mmo l:5mmo l:5mL:3mmol, and the amount of concentrated sulfuric acid is 3-5% of the total mass of dodecyldimethoxysilane, perfluorooctylmethyldimethoxysilane, dimethyldichlorosilane and 1,1,3,3-tetramethyldisiloxane.

[0068] The molar ratio of acrylic acid, diethanolamine, and 1-hydroxybenzotriazole in step A2 is 1:1:1.1, the molar ratio of intermediate 1, epichlorohydrin, and sodium hydroxide is 1:2:3, the mass fraction of sodium hydroxide solution is 30%, and the amount of benzyltrimethylammonium bromide is 2% by mass of intermediate 1 and epichlorohydrin.

[0069] The molar ratio of intermediate 3, intermediate 1 and levulinic acid described in step A3 is 2:1:4, the amount of chloroplatinic acid used is 0.01‰ of the sum of the mass of intermediate 1 and intermediate 3, and the amount of triphenylphosphine used is 0.01‰ of the mass of levulinic acid.

[0070] Comparative Example 1

[0071] Compared with Example 1, this comparative example uses Intermediate 2 instead of Intermediate 3, and Intermediate 2, Intermediate 1 and toluene are mixed uniformly, and nitrogen protection is introduced. At a speed of 200 r / min and a temperature of 50°C, stirring and chloroplatinic acid are added, and the reaction is carried out for 6 hours. The obtained reaction product replaces the modified monomer.

[0072] Comparative Example 2

[0073] Compared with Example 1, this comparative example uses allyl alcohol instead of intermediate 3. Allyl alcohol, intermediate 1 and toluene are mixed uniformly, and nitrogen protection is introduced. At a speed of 200 r / min and a temperature of 50°C, stirring and chloroplatinic acid are added, and the reaction is carried out for 6 hours. The obtained reaction product replaces the modified monomer.

[0074] The absolute dry pulp was prepared into a 0.5% by mass pulp with distilled water, and the pulp was dispersed for 1 min. The additives prepared in Examples 1-3 and Comparative Examples 1-2 were added respectively, and the amount of the additives added was 1% of the absolute dry pulp. After mixing evenly, the paper was copied on a paper sample copying machine with a basis weight of 160 g / m 2 The paper was used to prepare the sample.

[0075] According to GB / T4652-2008, paper was kept at a constant temperature and humidity of 23°C and 50% for 4 hours, cut into 12.5 cm × 1.27 cm strips, and the ring crush index of the paper was measured on a DYSY-1 compression tester.

[0076] According to the standard of GB / T4652-2008, the paper was kept at a constant temperature and humidity of 23°C and 50% relative humidity for 4 hours, cut into strips of 18 cm × 1.5 cm, and the tensile index of the paper was measured on a WZL-300 horizontal computer tensile tester.

[0077] The water absorption value of the paper was detected according to the standard of ISO5637:1989, and the detection results are as follows.

[0078]

[0079] It can be seen from the above table that the ring crush index of the paper treated with the pulp papermaking aid prepared in Examples 1-3 is 8.95-9.01 N·m / g, the tensile index is 60.12-60.25 N·m / g, and the water absorption value is 20.6-21.3 g / m 2 , indicating that the present invention can enhance the mechanical properties of the paper and enhance the waterproof effect.

[0080] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they shall fall within the protection scope of the present invention.

Claims

1. A preparation method of a pulp papermaking aid, characterized in that: Specifically, it includes the following steps: Step S1: Disperse corn starch and cellulose in deionized water, add acrylamide, methacryloyloxyethyl trimethyl ammonium chloride and propylene glycol methyl ether, stir and add ammonium persulfate, and carry out a reaction to obtain a composite emulsion; Step S2: Stir the composite emulsion and add a strengthening aid and dibutyltin dilaurate, carry out a reaction, and then add adipic dihydrazide and mix evenly to obtain a pulp papermaking aid; In Step S2, the dosage ratio of the composite emulsion to the strengthening aid is 25 mL: 2 g, the dosage of dibutyltin dilaurate is 4 - 6% of the mass of the strengthening aid, and the dosage of adipic dihydrazide is 1 - 3%; In Step S1, the dosage ratio of the corn starch, cellulose, deionized water, acrylamide, methacryloyloxyethyl trimethyl ammonium chloride and propylene glycol methyl ether is 1.5 g: 1 g: 10 mL: 0.6 g: 0.13 g: 0.01 g; The strengthening aid is prepared by the following steps: Mix and stir the modified monomer and castor oil, add diphenylmethane diisocyanate, carry out a reaction, then raise the temperature and continue the reaction to obtain a strengthening aid; The modified monomer is prepared by the following steps: Step A1: Mix and stir dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane, dimethyldichlorosilane and deionized water, add tetrahydrofuran and concentrated sulfuric acid, raise the temperature and keep it warm, add 1,1,3,3 - tetramethyldisiloxane, and carry out a reaction to obtain Intermediate 1; Step A2: React acrylic acid, diethanolamine, 1 - hydroxybenzotriazole and tetrahydrofuran to obtain Intermediate 2. Mix Intermediate 2, epichlorohydrin, benzyltrimethylammonium bromide and toluene and react, then lower the temperature and add sodium hydroxide solution, and carry out a reaction to obtain Intermediate 3; Step A3: Mix Intermediate 3, Intermediate 1 and toluene, stir and add chloroplatinic acid, carry out a reaction, then raise the temperature and add levulinic acid and triphenylphosphine, carry out a reaction, and continue to raise the temperature for reaction until the acid value is less than 10 mg / g to obtain the modified monomer.

2. The preparation method of a pulp papermaking aid according to claim 1, wherein: The molar ratio of the modified monomer, castor oil and diphenylmethane diisocyanate is n: 2n + 1: 4n + 2, where n is a natural number greater than 0.

3. A preparation method of a pulp papermaking aid according to claim 1, characterized in that: In Step A1, the dosage ratio of dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane, dimethyldichlorosilane, deionized water and 1,1,3,3 - tetramethyldisiloxane is 2 mmol: 3 mmol: 5 mmol: 5 mL: 3 mmol, and the dosage of concentrated sulfuric acid is 3 - 5% of the sum of the masses of dodecyl dimethoxysilane, perfluorooctyl methyl dimethoxysilane, dimethyldichlorosilane and 1,1,3,3 - tetramethyldisiloxane; 4. A preparation method of a pulp papermaking aid according to claim 1, characterized in that: In Step A2, the molar ratio of acrylic acid, diethanolamine and 1 - hydroxybenzotriazole is 1: 1: 1.1, the molar ratio of Intermediate 1, epichlorohydrin and sodium hydroxide is 1: 2: 3, the mass fraction of the sodium hydroxide solution is 30%, and the dosage of benzyltrimethylammonium bromide is 2% of the sum of the masses of Intermediate 1 and epichlorohydrin.

5. A method for preparing a pulp papermaking aid according to claim 1, characterized in that: The molar ratio of intermediate 3, intermediate 1 and levulinic acid described in step A3 is 2:1:

4. The dosage of chloroplatinic acid is 0.01‰ of the sum of the masses of intermediate 1 and intermediate 3, and the dosage of triphenylphosphine is 0.01‰ of the mass of levulinic acid.

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