AU2020103668A4 - Method for Surface Modification of Calcium Sulfate Whiskers - Google Patents
Method for Surface Modification of Calcium Sulfate Whiskers Download PDFInfo
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- AU2020103668A4 AU2020103668A4 AU2020103668A AU2020103668A AU2020103668A4 AU 2020103668 A4 AU2020103668 A4 AU 2020103668A4 AU 2020103668 A AU2020103668 A AU 2020103668A AU 2020103668 A AU2020103668 A AU 2020103668A AU 2020103668 A4 AU2020103668 A4 AU 2020103668A4
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- Prior art keywords
- calcium sulfate
- sulfate whisker
- surface modification
- solution
- whiskers
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Classifications
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- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B33/00—After-treatment of single crystals or homogeneous polycrystalline material with defined structure
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/46—Sulfur-, selenium- or tellurium-containing compounds
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/60—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape characterised by shape
- C30B29/62—Whiskers or needles
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Paper (AREA)
Abstract
The invention relates to the technical field of chemical material modification, in particular
to a surface modification method of calcium sulfate whiskers, which comprises the following
steps of: preparing anhydrous calcium sulfate whiskers; preparing a solution of a surface
modifier; slowly adding the anhydrous calcium sulfate whiskers into the solution of the surface
modifier while stirring, and slowly stirring and reacting; and performing solid-liquid
separation, washing and drying treatment on the modified calcium sulfate whiskers to obtain
an anhydrous calcium sulfate whisker product. The method is featured with simple processes
and steps, less raw materials, and can reduce the water treatment burden. The calcium sulfate
whisker product is featured with good performance, high paper-making retention rate, high
tensile strength, high tearing strength, high folding resistance and high pop strength.
Description
Method for Surface Modification of Calcium Sulfate Whiskers
The invention relates to the technical field of chemical material modification, in particular to a surface modification method of calcium sulfate whiskers.
Calcium sulfate whiskers, also known as gypsum whiskers, are fibrous mono crystals of calcium sulfate, which can be divided into calcium sulfate dihydrate, calcium sulfate hemihydrate or anhydrous calcium sulfate. The calcium sulfate whisker, integrated with the advantages of superfine inorganic materials and reinforced fibers, has excellent physical and chemical properties such as high mechanical strength, high modulus, high dielectric strength, wear resistance, high temperature resistance, corrosion resistance and no fatigue effect, and has good development prospect as a reinforcing material of paper. In addition, the calcium sulfate whiskers have incomparable cost performance of other whiskers, and the popularization and application of the calcium sulfate whiskers in the paper making industry are bound to bring considerable economic benefits. However, because the surface properties and forms of the whiskers and the fibers are different, there are significant differences in the surface polarity, the surface chemical composition and the surface energy, and as a result, the interaction force between the whiskers and the fibers is weak, the interface binding force is poor, and the binding force between the whiskers and the fibers is reduced along with the increase of the loading of the filler; furthermore, the calcium sulfate whiskers are easy to generate hydration reaction after being contacted with water, so that the crystal structure and the performance of the whiskers are unstable, and the strength, the bulk and the stiffness of the paper are reduced, as well as the abrasion of the paper machine and the hair slip and picking of the paper. When being directly used as a paper-making raw material, the calcium sulfate whisker can cause low retention rate and reduced paper strength in the paper-making process due to the characteristics of instability and less organic chemical bonds on the surface of the calcium sulfate whisker.
Based on the technical problems, the invention provides a method for the surface modification of calcium sulfate whiskers, which overcomes the technical problems of low retention rate of the calcium sulfate whiskers in the paper making process, low tensile strength, low tearing strength, low folding strength and pop strength of paper, large waste of raw materials and high cost of water treatment.
The invention is implemented by the following embodiment: a method for the surface modification of the calcium sulfate whiskers, which comprises the following steps:
Disperse anhydrous calcium sulfate whiskers in a surface modifier solution, heat it up, stir for reaction, and after reaction, filter it to obtain modified calcium sulfate whiskers;
The surface modifier comprises sodium hexametaphosphate, potassium tripolyphosphate and zinc sulfate in a mass ratio of 0.8-1.0:0.5-1.0:0.8-1.0.
Further, the addition amount of the surface modifier is 0.1-10% of the mass of the anhydrous calcium sulfate whisker.
Further, the heating and stirring reaction temperature is 80-90°C, and the stirring reaction time is 10-20 min.
Further, the pH of the surface modifier solution is 8-10.
Further, after heating and stirring the anhydrous calcium sulfate crystal whisker in the surface modifier solution for reaction, add gelatinized cationic starch and then continue to stir for reaction, and then apply the suction filtration and drying method to obtain the modified calcium sulfate crystal whisker.
Further, the addition amount of the gelatinized cationic starch is 0.5-1% of the mass of the anhydrous calcium sulfate whisker.
Further, the gelatinization point of the gelatinized cationic starch is 95°C, and the gelatinization time is 30 min.
Further, the temperature of adding the gelatinized cationic starch is 40-5 0 °Cand stirring time for continuous reaction is 3-5 min.
Further, the preparation method of the anhydrous calcium sulfate whisker comprises the following steps of: adding crystal growth substance into industrial waste water containing Ca2, heating up the solution, adding, dropwise, a sulfuric acid solution until Ca 2+is completely precipitated, aging the precipitate, then filtering, washing and drying to obtain the anhydrous calcium sulfate whisker.
Further, the crystal growth substance is MgCl2.6H20, the heating temperature of the solution is over 40°C, the concentration of the sulfuric acid solution is 10-40%, the aging time is 2-8 h, and the drying temperature is 200-450°C.
Compared with the prior art, the invention has the following beneficial effects:
(1) In the technical scheme of the invention, firstly place the calcium sulfate whiskers are in mixed solution of sodium hexametaphosphate, potassium tripolyphosphate and zinc sulfate, then stir it while heating for reaction. In the reaction process, the sodium hexametaphosphate will form a layer of calcium phosphate which is more difficult to dissolve on the surface of the calcium sulfate whiskers and can stop the dissolution of the internal calcium sulfate; when dissolving the potassium tripolyphosphate in water, polyphosphate exists in the form of medium- and long-chain, which makes it easy to connect the calcium phosphate formed on the surface of calcium sulfate via chemical bonds, and then form the medium- and long-chain organic layer rich in hydroxyl; meanwhile, the inorganic phosphate and zinc sulfate can also be used as the chelating agent of Ca2+ ligand, which can assist to achieve the full complexation of the modified whisker Ca2, form more stable combination of modifier and whisker. As a result, its addition into the paper can improve the tensile strength, tearing strength, folding strength, pop strength and others.
(2) After modifying the calcium sulfate whisker by placing it into the mixed solution of the sodium hexametaphosphate, the potassium tripolyphosphate and the zinc sulfate, further add gelatinized cationic starch to wrap the modified calcium sulfate, wherein the gelatinized cationic starch belongs to a long-chain organic compound. After being dissolved in water, the functional groups on the chain are easily combined with the polymerized phosphoric acid chain in the form of hydrogen bonds to complete grafting. After being grafted by cationic starch, the surface chemical property of the calcium sulfate whisker is basically consistent with the surface of the plant fiber. As a result, the modified calcium sulfate whisker can be used as a paper-making raw material to increase the retention rate of the modified calcium sulfate whisker in paper-making and the tensile strength of paper.
Various exemplary embodiments of the present invention will now be described in detail, which is not to be construed as limiting the invention, but rather is to be construed as a more detailed description of certain aspects, features and embodiments of the invention.
It is to be understood that the terminology described herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. each smaller range between intermediate values within any stated value or stated range and any other stated value or intermediate values within the stated range is also included within the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention relates. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention. all documents mentioned in this specification are incorporated by reference for the purpose of disclosing and describing methods and/or materials related to said documents. the contents of this specification prevail in conflict with any incorporated document.
It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present specification without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from the description of the invention. The specification and embodiments of the present application are exemplary only.
As used herein, terms "comprising,""consisting,""having,""containing," and the like, are intended to be open terms, i. e., intended to include, but not be limited to.
Embodiment 1
Prepare anhydrous calcium sulfate whisker: weigh 11.8 g of Ca (NO 3 ) 2.4H 2 0, dissolve it in 500 ml of tap water, prepare 0.1 mol/L calcium nitrate solution, add crystal growth substance MgCl2.6H20, wherein the molar ratio of calcium to magnesium is 13: 1; filter to remove insoluble impurities and then place it well for later use, which is labeled as Solution A. Heat the Solution A in water bath to keep the temperature of the Solution A being above 40°C, add, dropwise, a sulfuric acid solution with the concentration of 10% until Ca2+is completely precipitated, age it for 8 hours, then filter, wash and dry it at 450°C to obtain the anhydrous calcium sulfate whisker.
Embodiment 2
Preparation of the surface modifier solution: dissolve sodium hexametaphosphate, potassium tripolyphosphate and zincsulfate with the mass ratio of 1:1:1 in water to form a surface modifier solution with the total concentration of 5% and add sodium hydroxide to adjust the pH value to 10;
Modification of anhydrous calcium sulfate whisker: stir and heat up the solution of the surface modifier to 85°C, add the anhydrous calcium sulfate whisker prepared in the Embodiment 1, and the mass of surface modifier is 5% of the addition amount of the anhydrous calcium sulfate whisker; stir them for reaction, 15 min later, filter, wash and dry to obtain the modified calcium sulfate whisker.
Embodiment 3
Preparation of surface modifier solution as in Embodiment 2;
Stir and heat up the surface modifier solution to 85°C, and add the anhydrous calcium sulfate whisker prepared in Embodiment 1, and the mass of the surface modifier in the solution is 5% of the addition amount of the anhydrous calcium sulfate whisker; stir them for reaction, 15 min later, when the temperature cools down to 50°C, add gelatinized cationic starch, continuously stir for reaction for 3 min (the gelatinization point temperature of the gelatinized cationic starch is 95°C, the gelatinization time is 30 min, and the adding amount of the gelatinized cationic starch is 0.5% of the mass of the anhydrous calcium sulfate whisker), and then carry out suction filtration and drying treatment to obtain the modified calcium sulfate whisker.
Embodiment 4
As in Embodiment 3, the difference is that the 2-step modification reaction temperature is 50°C.
Embodiment 5
As in Embodiment 3, the difference is that the 2-step modification reaction temperature is 85°C.
Embodiment 6
As in Embodiment 3, the difference is that there is no sodium hexametaphosphate contained in surface modifier solution.
Embodiment 7
As in Embodiment 3, the difference is that there is no zinc sulfate contained in surface modifier solution.
Embodiment 8
As in Embodiment 3, the difference is that there is no potassium tripolyphosphate contained in surface modifier solution.
Effect Verification
Add the modified calcium sulfate crystal whisker prepared in Embodiments 2-8 into paper-making wood pulp, then obtain the reinforcing finished paper with the calcium sulfate crystal whisker through the processes of pressing and drying. Wherein the addition amount of the modified calcium sulfate is 40% of that of the wood pulp, and test the finished paper added with the modified calcium sulfate whiskers prepared in Embodiments 2-8, with the paper performance results shown in Table 1 below.
Table 1
Whisker retention Tensile index Tensile strength rate index ratio
Embodiment 2 90% 14.547 115.47%
Embodiment 3 95% 15.148 126.49%
Embodiment 4 85% 13.497 104.75%
Embodiment 5 82% 13.451 102.46%
Embodiment 6 75% 13.225 103.41%
Embodiment 7 77% 12.954 102.77%
Embodiment 8 75% 12.887 101.94%
Unmodified 18% 12.154 84.75% calcium sulfate whisker
Pure wood pulp 10.025 100%
As can be seen from the data in Table 1, when the modified calcium sulfate whisker prepared by the method of the invention is used for paper, the whisker retention rate and the paper quality can be remarkably improved.
The foregoing is to be considered as preferred embodiments of the invention and is not intended to be limiting of the invention, and any modifications, equivalents, and alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (10)
1. A method for surface modification of calcium sulfate whisker, comprising the steps of:
Dispersing anhydrous calcium sulfate whiskers in a surface modifier solution, heating it up, stirring for reaction, and filtering to obtain modified calcium sulfate whiskers;
The surface modifier comprises sodium hexametaphosphate, potassium tripolyphosphate and zinc sulfate in a mass ratio of 0.8-1.0:0.5-1.0:0.8-1.0.
2. The method for surface modification of calcium sulfate whisker according to Claim 1, which is characterized in that the surface modifier is added in an amount of 0.1 % by mass of anhydrous calcium sulfate whisker.
3. The method for surface modification of calcium sulfate whisker according to Claim 1, which is characterized in that the heating and stirring reaction temperature is 80 °C, and the stirring reaction time is 10-20 min.
4. The method for surface modification of calcium sulfate whisker according to Claim 1, which is characterized in that the pH value of the surface modifier solution is 8 10.
5. The method for surface modification of calcium sulfate whisker according to Claim 1, which is characterized in that after the anhydrous calcium sulfate whisker is heated and stirred in a surface modifier solution for reaction, add gelatinized cationic starch and stir for continuous reaction, and then obtain the modified calcium sulfate whisker is obtained via suction filtration and drying treatment.
6. The method for surface modification of calcium sulfate whiskers according to Claim 5, which is characterized in that the gelatinized cationic starch is added in an amount of 0.5-1% by mass of anhydrous calcium sulfate whiskers.
7. The method for surface modification of calcium sulfate whisker according to Claim 5, which is characterized in that the gelatinization point of the gelatinized cationic starch is 95°C, and the gelatinization time is 30 min.
8. The method for modifying the surface of a calcium sulfate whisker according to Claim 5, which is characterized in that the gelatinized cationic starch is added at a temperature of 40- 50°C and stirring time for continuous reaction is 3-5 min.
9. The method for surface modification of calcium sulfate whisker according to Claim 1, which is characterized in that the method for preparing the anhydrous calcium sulfate whisker comprises the following steps: add crystal growth substance into industrial waste water containing Ca2, heat up the solution, add, dropwise, the sulfuric acid solution until Ca2+is completely precipitated, age the precipitate, filter, wash and dry to obtain the anhydrous calcium sulfate whisker.
10. The method for surface modification of calcium sulfate whisker according to Claim 9, which is characterized in that the crystal growth substance is MgC2.6H20, the heating temperature of the solution is over 40°C, the concentration of the sulfuric acid solution is 10%-40%, the aging time is 2-8 h, and the drying temperature is 200-450°C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| AU2020103668A AU2020103668A4 (en) | 2020-11-25 | 2020-11-25 | Method for Surface Modification of Calcium Sulfate Whiskers |
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| AU2020103668A AU2020103668A4 (en) | 2020-11-25 | 2020-11-25 | Method for Surface Modification of Calcium Sulfate Whiskers |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113061972A (en) * | 2021-03-05 | 2021-07-02 | 宁夏鑫浩源生物科技股份有限公司 | Method for producing calcium sulfate whiskers by using high-chlorine-root wastewater generated in bone gelatin production |
| CN114292476A (en) * | 2021-12-31 | 2022-04-08 | 山东日科化学股份有限公司 | Multifunctional compound polarity modified inorganic micro-nano filler and preparation method thereof |
| CN114775059A (en) * | 2022-06-20 | 2022-07-22 | 国能龙源环保有限公司 | System and method for preparing gypsum whiskers by comprehensively utilizing concentrated salt wastewater and gypsum whiskers |
| CN115787970A (en) * | 2022-11-21 | 2023-03-14 | 常州华通新立地板有限公司 | Anti-static movable floor and preparation method thereof |
| CN115849426A (en) * | 2022-11-29 | 2023-03-28 | 四川青环达科技有限责任公司 | Method and system for purifying mud-containing natural gypsum and application of purified gypsum |
| CN116024848A (en) * | 2023-01-30 | 2023-04-28 | 大家智合(北京)网络科技股份有限公司 | Coffee grounds pulp packaging material for packaging coffee and preparation method thereof |
| CN116970242A (en) * | 2023-09-22 | 2023-10-31 | 一夫科技股份有限公司 | Calcium sulfate whisker reinforced polypropylene and preparation method thereof |
| CN117534396A (en) * | 2023-10-31 | 2024-02-09 | 广东合睿智造新材料有限公司 | Double-component-based adhesive for pasting large-size ceramic tiles and preparation method thereof |
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2020
- 2020-11-25 AU AU2020103668A patent/AU2020103668A4/en not_active Ceased
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113061972B (en) * | 2021-03-05 | 2022-06-28 | 宁夏鑫浩源生物科技股份有限公司 | Method for producing calcium sulfate whiskers by using high-chloride-content wastewater generated in bone gelatin production |
| CN113061972A (en) * | 2021-03-05 | 2021-07-02 | 宁夏鑫浩源生物科技股份有限公司 | Method for producing calcium sulfate whiskers by using high-chlorine-root wastewater generated in bone gelatin production |
| CN114292476A (en) * | 2021-12-31 | 2022-04-08 | 山东日科化学股份有限公司 | Multifunctional compound polarity modified inorganic micro-nano filler and preparation method thereof |
| CN114775059A (en) * | 2022-06-20 | 2022-07-22 | 国能龙源环保有限公司 | System and method for preparing gypsum whiskers by comprehensively utilizing concentrated salt wastewater and gypsum whiskers |
| CN115787970A (en) * | 2022-11-21 | 2023-03-14 | 常州华通新立地板有限公司 | Anti-static movable floor and preparation method thereof |
| CN115787970B (en) * | 2022-11-21 | 2024-06-25 | 常州华通新立地板有限公司 | Anti-static movable floor and preparation method thereof |
| CN115849426B (en) * | 2022-11-29 | 2024-05-07 | 桂明生 | Method for purifying natural gypsum containing mud, purifying system and application of purified gypsum |
| CN115849426A (en) * | 2022-11-29 | 2023-03-28 | 四川青环达科技有限责任公司 | Method and system for purifying mud-containing natural gypsum and application of purified gypsum |
| CN116024848A (en) * | 2023-01-30 | 2023-04-28 | 大家智合(北京)网络科技股份有限公司 | Coffee grounds pulp packaging material for packaging coffee and preparation method thereof |
| CN116024848B (en) * | 2023-01-30 | 2024-03-26 | 大家智合(北京)网络科技股份有限公司 | Coffee grounds pulp packaging material for packaging coffee and preparation method thereof |
| CN116970242B (en) * | 2023-09-22 | 2023-12-08 | 一夫科技股份有限公司 | Calcium sulfate whisker reinforced polypropylene and preparation method thereof |
| CN116970242A (en) * | 2023-09-22 | 2023-10-31 | 一夫科技股份有限公司 | Calcium sulfate whisker reinforced polypropylene and preparation method thereof |
| CN117534396A (en) * | 2023-10-31 | 2024-02-09 | 广东合睿智造新材料有限公司 | Double-component-based adhesive for pasting large-size ceramic tiles and preparation method thereof |
| CN117534396B (en) * | 2023-10-31 | 2024-04-19 | 广东合睿智造新材料有限公司 | Double-component-based adhesive for pasting large-size ceramic tiles and preparation method thereof |
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