CN112482082B - Wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose and preparation method thereof - Google Patents
Wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose and preparation method thereof Download PDFInfo
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- CN112482082B CN112482082B CN202011432386.5A CN202011432386A CN112482082B CN 112482082 B CN112482082 B CN 112482082B CN 202011432386 A CN202011432386 A CN 202011432386A CN 112482082 B CN112482082 B CN 112482082B
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
- D21H17/24—Polysaccharides
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
- C08B37/0003—General processes for their isolation or fractionation, e.g. purification or extraction from biomass
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
- C08B37/006—Heteroglycans, i.e. polysaccharides having more than one sugar residue in the main chain in either alternating or less regular sequence; Gellans; Succinoglycans; Arabinogalactans; Tragacanth or gum tragacanth or traganth from Astragalus; Gum Karaya from Sterculia urens; Gum Ghatti from Anogeissus latifolia; Derivatives thereof
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/06—Paper forming aids
- D21H21/10—Retention agents or drainage improvers
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/18—Reinforcing agents
- D21H21/20—Wet strength agents
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- Health & Medical Sciences (AREA)
- Biochemistry (AREA)
- Molecular Biology (AREA)
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- General Health & Medical Sciences (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
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Abstract
The invention discloses a wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose, which comprises the following raw materials in percentage by weight: 10-15% of phosphorus-doped carboxymethyl hemicellulose, 50-85% of cellulose solvent and 1.5-10% of pH regulator. In the phosphorus-doped carboxymethyl hemicellulose, part of carbon atoms of the wood fiber are replaced by phosphorus atoms to generate a large number of structural defects, so that more chemical active sites are generated, the interaction between a wet strength agent with positive charges and paper pulp fibers with negative charges is improved, and the dry strength of paper can be improved; besides, the hydrophobic polymer network formed among the wet strength agent molecules and between the wet strength agent and the pulp fiber can be more compact, and the strength of the paper after being wetted can be further improved. Thereby improving the efficiency of the wet strength synergist containing the phosphorus-doped carboxymethyl hemicellulose, improving the dry tensile index, the wet tensile index and the wet strength retention value of the paper, and obviously improving the comprehensive performance.
Description
Technical Field
The invention belongs to the technical field of development and utilization of papermaking green chemicals, and particularly relates to a wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose and a preparation method thereof.
Background
The paper product loses a significant portion of its strength when wetted with a liquid, and the strength retained is commonly referred to as wet strength (strength is often referred to herein as tensile strength). Since the tensile strength of paper is often affected by factors such as basis weight, formation, etc., and it is difficult to obtain a precise absolute value, the wet strength of paper is often expressed as wet tensile index/dry tensile index, which is called wet-to-dry tensile index ratio, which is also called retention, expressed in percent.
Reinforcing agents, known as wet strength agents, which maintain a dry strength of the paper web of more than 15% after the paper is fully wetted. Paper having a ratio of strength after full wetting to its dry strength of more than 15% is known as wet-strength paper. The wet strength agent has a positive charge, can be tightly combined with pulp fibers with negative charges, and can improve the dry strength of paper. The wet strength agent is characterized in that: the molecular structure of the wet strength agent contains specific active groups, and chemical reactions can occur among wet strength agent molecules and between the wet strength agent and pulp fibers to form a hydrophobic polymer network. Due to the existence of the polymer network, when the paper is wetted by water, the polymer network can protect hydrogen bonds among pulp fibers from being damaged by the water, thereby improving the strength of the paper after being wetted. The wet-dry tensile index ratio of the current common non-wet strength paper is about 2-10%, after the wet strength agent is added, the wet-dry tensile index ratio of the paper can reach 20-40%, and with the improvement of the speed and the yield of a modern paper machine, the use ratio of waste paper and the closed circulation degree of water, the current simple wet strength agent cannot meet the requirements of the modern paper machine.
Disclosure of Invention
In view of the problems of the prior art, it is an object of the present invention to provide a wet strength enhancer comprising phosphorus-doped carboxymethyl hemicellulose. The invention also aims to provide a preparation method of the wet strength synergist containing the phosphorus-doped carboxymethyl hemicellulose. The invention is used together with dry strength agent, which can obviously improve the comprehensive performances of paper such as stiffness, tensile strength, folding strength, bursting strength, tearing resistance and the like, and has the functions of retention and drainage.
The invention adopts the following technical scheme:
a wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose comprises the following raw materials in percentage by weight:
10 to 15 percent of phosphorus-doped carboxymethyl hemicellulose,
50-85% of cellulose solvent,
1.5-10% of PH regulator.
Further, the cellulose solvent is selected from one or more of N-methylmorpholine-N-oxide/N-methylpyrrolidone/water, lithium chloride/N, N-dimethylacetamide, N-methylmorpholine-N-oxide/water.
Further, the special efficient agent for papermaking is yellowish or transparent viscous liquid.
Further, the solid content of the special papermaking high-efficiency agent is more than or equal to 7.0%.
Further, the viscosity (25 ℃, mPa.s) of the special high-efficiency agent for papermaking is 2000-6000.
Further, the content of water-insoluble substances in the special efficient agent for papermaking is less than or equal to 0.01.
Further, the pH value of the special efficient agent for papermaking is 4-6.5.
The preparation method of the phosphorus-doped carboxymethyl hemicellulose comprises the following steps:
(1) adding 0.1-1mol/ml alkali solution into 150-200g of wood fiber raw material for extraction, filtering, and taking filtrate to obtain hemicellulose solution; adding an organic solvent into the hemicellulose solution, standing, centrifuging and drying to obtain hemicellulose;
(2) dispersing the hemicellulose obtained in the step (1) into an organic solvent, then adding an alkali solution for an alkalization reaction, and then adding chloroacetic acid for an etherification reaction to obtain a reaction solution;
(3) and adding 12-15g of phosphorus source solution into the reaction solution, introducing protective gas, carrying out heat treatment reaction, cooling to room temperature, washing, and drying in vacuum to obtain the phosphorus-doped carboxymethyl hemicellulose.
Further, the wood fiber comprises plant fiber, bacterial cellulose, biological cellulose or microcrystalline cellulose.
Further, the phosphorus doping amount in the phosphorus-doped carboxymethyl hemicellulose is 10 wt% to 25 wt% (e.g., 10, 11, 13, 15, 17, 19, 21, 23, 25 wt%).
Further, the organic solvent in the step (1) is absolute ethyl alcohol.
Further, the alkali solution in the steps (1) and (2) is NaOH, KOH or LiOH solution.
Further, the organic solvent in the step (2) is one or more of ethanol, isopropanol and toluene.
Further, the flow rate of the protective gas in the step (3) is 150-; the protective gas is helium.
Further, the time of the heat treatment reaction in the step (3) is 3-4h (e.g. 3, 3.5, 4 h).
Further, washing in the step (3) is carried out by using water and/or ethanol; the temperature of the vacuum drying is 50-70 deg.C, preferably 60 deg.C, and the vacuum degree is not more than 133Pa, such as not more than 125, 115, 105, 95, 85 Pa.
Further, the phosphorus source solution in the step (3) is one or more of triphenylphosphine solution, sodium dihydrogen phosphate solution and potassium dihydrogen phosphate solution.
A phosphorus-doped carboxymethyl hemicellulose prepared by a preparation method of the phosphorus-doped carboxymethyl hemicellulose.
Further, the phosphorus-doped carboxymethyl hemicellulose is a high molecular polymer.
In the phosphorus-doped carboxymethyl hemicellulose, part of carbon atoms of the wood fiber are replaced by phosphorus atoms to generate a large number of structural defects, so that more chemical active sites are generated, the interaction between a wet strength agent with positive charges and paper pulp fibers with negative charges is improved, and the dry strength of paper can be improved; besides, the hydrophobic polymer network formed among the wet strength agent molecules and between the wet strength agent and the pulp fiber can be more compact, and the strength of the paper after being wetted can be further improved. Thereby improving the efficiency of the wet strength synergist containing the phosphorus-doped carboxymethyl hemicellulose and improving the comprehensive performances of tension resistance, folding strength, bursting strength, tear resistance and the like of paper.
A method of using the wet strength enhancer comprising phosphorus-doped carboxymethyl hemicellulose:
diluting the wet strength synergist containing the phosphorus-doped carboxymethyl hemicellulose by more than 15 times with clear water, directly adding the wet strength synergist into a ground pulp chest or an outlet of the ground pulp chest, and adding the wet strength synergist into the outlet of the ground pulp chest.
Further, the amount is 0.5% -1.2% per ton of dry paper.
The invention has the beneficial effects that:
1. the comprehensive properties of the paper such as dry strength, wet strength, tensile strength, tear resistance and the like are improved;
2. the retention rate of the fiber filler is improved, and the fiber filler has good drainage-assisting effect;
3. the long fiber consumption is reduced, and the cost is saved.
Detailed Description
For better explanation of the present invention, the following specific examples are further illustrated, but the present invention is not limited to the specific examples.
Example 1
A preparation method of phosphorus-doped carboxymethyl hemicellulose comprises the following steps:
(1) adding 0.1mol/ml NaOH solution into 150g of plant fiber raw material, extracting, filtering, and taking filtrate to obtain hemicellulose solution; adding absolute ethyl alcohol into the hemicellulose solution, standing, centrifuging and drying to obtain hemicellulose;
(2) dispersing the hemicellulose obtained in the step (1) into ethanol, adding an alkali solution for an alkalization reaction, and adding chloroacetic acid for an etherification reaction to obtain a reaction solution;
(3) and adding 12g of triphenylphosphine solution into the reaction solution, introducing protective gas, carrying out heat treatment reaction, cooling to room temperature, washing, and drying in vacuum to obtain the phosphorus-doped carboxymethyl hemicellulose.
The flow rate of the protective gas in the step (3) is 150 ml/min; the protective gas is helium.
The time of the heat treatment reaction in the step (3) is 3 h.
Washing with water in the step (3); the temperature of vacuum drying is 50 ℃ and the vacuum degree is 125 Pa.
Example 2
A preparation method of phosphorus-doped carboxymethyl hemicellulose comprises the following steps:
(1) adding 1mol/ml KOH solution into 200g of bacterial cellulose raw material for extraction, filtering, and taking filtrate to obtain hemicellulose solution; adding absolute ethyl alcohol into the hemicellulose solution, standing, centrifuging and drying to obtain hemicellulose;
(2) dispersing the hemicellulose obtained in the step (1) into isopropanol, adding a KOH solution for an alkalization reaction, and adding chloroacetic acid for an etherification reaction to obtain a reaction solution;
(3) and adding 12-15g of sodium dihydrogen phosphate solution into the reaction solution, introducing protective gas, carrying out heat treatment reaction, cooling to room temperature, washing, and drying in vacuum to obtain the phosphorus-doped carboxymethyl hemicellulose.
Further, the flow rate of the protective gas in the step (3) is 160 ml/min; the protective gas is helium.
Further, the time of the heat treatment reaction in the step (3) is 4 h.
Further, washing in the step (3) is carried out by using ethanol; the temperature of vacuum drying is 70 ℃, and the vacuum degree is 85 Pa.
Example 3
A wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose comprises the following raw materials in percentage by weight:
10% of the phosphorus-doped carboxymethyl hemicellulose prepared in example 1,
N-methylmorpholine-N-oxide/N-methylpyrrolidone 85%,
5 percent of PH regulator.
Diluting the wet strength synergist containing the phosphorus-doped carboxymethyl hemicellulose by 15 times with clear water, directly adding the diluted wet strength synergist into a ground pulp chest, adding the wet strength synergist into an outlet of the ground pulp chest, and preparing paper by adopting a conventional technical means.
Example 4
A wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose comprises the following raw materials in percentage by weight:
15% of the phosphorus-doped carboxymethyl hemicellulose prepared in example 2,
80 percent of lithium chloride/N, N-dimethylacetamide,
5 percent of PH regulator.
Diluting the wet strength synergist containing the phosphorus-doped carboxymethyl hemicellulose by 18 times with clear water, directly adding the diluted wet strength synergist into an outlet of a ground pulp chest, adding the wet strength synergist into the outlet of the ground pulp chest, and preparing paper by adopting a conventional technical means.
Comparative example 1
Paper was made in the same manner as in example 3 except that the wet strength enhancer comprising phosphorus-doped carboxymethyl hemicellulose was not added.
Comparative example 2
Paper was made in the same manner as in example 4 except that the wet strength enhancer comprising phosphorus-doped carboxymethyl hemicellulose was not added.
The dry tensile index, wet tensile index and wet strength retention values of the papers obtained in examples 3, 4 and comparative examples 1, 2 were measured according to industry standards and the results are shown in table 1.
TABLE 1
As can be seen from table 1, in the phosphorus-doped carboxymethyl hemicellulose of the present invention, a part of carbon atoms of the wood fibers are replaced by phosphorus atoms, which generates a large number of structural defects, thereby causing more chemically active sites, improving the interaction between the wet strength agent with positive charges and the pulp fibers with negative charges, and simultaneously improving the dry strength of the paper; besides, the hydrophobic polymer network formed among the wet strength agent molecules and between the wet strength agent and the pulp fiber can be more compact, and the strength of the paper after being wetted can be further improved. Thereby improving the efficiency of the wet strength synergist containing the phosphorus-doped carboxymethyl hemicellulose, improving the dry tensile index, the wet tensile index and the wet strength retention value of the paper, and obviously improving the comprehensive performance.
The above description is only exemplary of the present invention and is not intended to limit the scope of the present invention, which is defined by the claims appended hereto, as well as the appended claims.
Claims (4)
1. The wet strength synergist containing phosphorus-doped carboxymethyl hemicellulose is characterized by comprising the following raw materials in percentage by weight:
10 to 15 percent of phosphorus-doped carboxymethyl hemicellulose,
50-85% of cellulose solvent,
1.5 to 10 percent of pH regulator;
the preparation method of the phosphorus-doped carboxymethyl hemicellulose comprises the following steps:
(1) adding 0.1-1mol/ml alkali solution into 150-200g of wood fiber raw material for extraction, filtering, and taking filtrate to obtain hemicellulose solution; adding an organic solvent into the hemicellulose solution, standing, centrifuging and drying to obtain hemicellulose;
(2) dispersing the hemicellulose obtained in the step (1) into an organic solvent, adding an alkali solution for an alkalization reaction, and adding chloroacetic acid for an etherification reaction to obtain a reaction solution;
(3) adding 12-15g of phosphorus source solution into the reaction solution, introducing protective gas, carrying out heat treatment reaction, cooling to room temperature, washing, and drying in vacuum to obtain phosphorus-doped carboxymethyl hemicellulose, wherein the phosphorus doping amount in the phosphorus-doped carboxymethyl hemicellulose is 10-25 wt%, and the time of the heat treatment reaction is 3-4 hours;
the cellulose solvent is selected from one or more of N-methylmorpholine-N-oxide/N-methylpyrrolidone/water, lithium chloride/N, N-dimethylacetamide and N-methylmorpholine-N-oxide/water.
2. The wet strength enhancer of claim 1, wherein the phosphorus source solution of step (3) is one or more of triphenylphosphine solution, sodium dihydrogen phosphate solution, and potassium dihydrogen phosphate solution.
3. The wet strength enhancer as claimed in claim 1, wherein the flow rate of the protective gas in step (3) is 150-160 ml/min; the protective gas is helium.
4. The method for using the wet strength enhancer containing the phosphorus-doped carboxymethyl hemicellulose as claimed in claim 1, wherein the wet strength enhancer containing the phosphorus-doped carboxymethyl hemicellulose is diluted by more than 15 times with clear water and is directly added into a post-mill chest or an outlet of the post-mill chest, and the wet strength agent is added at the outlet of the post-mill chest.
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| WO2015126468A1 (en) * | 2014-02-19 | 2015-08-27 | Celanese Acetate Llc | Hemicellulose compositions |
| CN108485660A (en) * | 2018-03-12 | 2018-09-04 | 大连工业大学 | A kind of preparation method and application of cellulose base N doping fluorescent carbon quantum dot |
| CN109162144B (en) * | 2018-08-15 | 2020-04-28 | 华南理工大学 | Preparation method and application of paper and paper product wet strength synergist |
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