Adsorption type paper as well as preparation method and application thereof

Abstract

The invention discloses adsorption type paper as well as a preparation method and application thereof. The adsorption type paper comprises oxidized cellulose, nano cellulose, zeolite powder, calcium salt, polyethylene glycol and chitosan, and the preparation method comprises the following steps: 1) preparing the zeolite powder, the calcium salt and the polyethylene glycol into slurry A, and preparing the oxidized cellulose and the nano cellulose into slurry B; 2) uniformly mixing the slurry A and the slurry B to obtain slurry C; and 3) dissolving chitosan in an acetic acid solution, adding the solution into the slurry C, uniformly mixing, and carrying out papermaking and molding. The adsorption type paper has the advantages of being high in adsorption efficiency, excellent in mechanical performance, uniform in pore structure, good in air permeability and the like, can effectively adsorb peculiar smell molecules emitted by durian when serving as a packaging material, can effectively avoid ripening deterioration of the durian in the transportation process, and is suitable for air transportation of the durian.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of packaging materials, in particular to an adsorption type paper and a preparation method and application thereof. BACKGROUND

[0002] Fresh durians (freshly picked durian fruits, not vacuum-packed durian fruits for cold storage, which need to maintain ventilation to ensure natural ripening) are usually placed in the belly of a passenger plane during air transportation, and the peculiar smell (mainly from ethanethiol) emitted by durians will disturb passengers on the plane. At present, the following methods are mainly used to eliminate the peculiar smell emitted by durians: 1) physical isolation of durians by using airtight packaging film, but long-term airtight packaging transportation is easy to cause durian ripening and deterioration; 2) neutralization of the peculiar smell molecules emitted by durians by using deodorizing agents, but this method is not suitable for air transportation, and the use of deodorizing agents has potential safety risks; 3) adsorption of the peculiar smell molecules emitted by durians by using adsorption materials, which can remove the pungent smell emitted by durians while ensuring ventilation and preservation of the package, and has good application prospect.

[0003] However, the current main way to eliminate the peculiar smell emitted by durians is to put the adsorption material into the box containing durians, which cannot guarantee that the peculiar smell molecules emitted by durians are completely adsorbed by the adsorption material in the process of thermal motion. Since the air circulation system of the narrow-body belly of the plane is connected to the passenger cabin, if the adsorption material cannot timely adsorb the peculiar smell molecules emitted by durians, it is easy to cause the peculiar smell molecules to leak out. Therefore, the adsorption material needs to be used for the outer packaging of the durian box, so as to ensure that the peculiar smell molecules emitted by durians are timely adsorbed by the adsorption material when they pass through the outer packaging into the cargo hold.

[0004] Japanese patent JP 4149066 B2 discloses a paper with odor adsorption capacity, which is obtained by loading zeolite in the interior of cellulose and then papermaking the cellulose to obtain a paper with odor adsorption capacity. However, since the zeolite is attached to the surface of the cellulose fiber by physical loading, the zeolite is easy to fall off and difficult to contact and adsorb gas molecules, which finally leads to unsatisfactory actual use effect of the paper with odor adsorption capacity.

[0005] Therefore, it is of great significance to develop a packaging material that can effectively intercept the peculiar smell emitted by durians, has excellent mechanical properties and good ventilation. SUMMARY

[0006] The present application aims to provide an adsorption type paper and a preparation method and application thereof.

[0007] The technical scheme adopted by the present application is as follows:

[0008] An adsorption type paper comprises the following components by weight:

[0009] Oxidized cellulose: 20 to 80 parts;

[0010] Nanocellulose: 1 part to 20 parts;

[0011] Zeolite powder: 10 to 60 parts;

[0012] Calcium salts: 1 to 20 parts;

[0013] Polyethylene glycol: 0.1 parts to 4 parts;

[0014] Chitosan: 0.1 to 2 parts.

[0015] Preferably, an absorbent paper comprises the following components in parts by weight:

[0016] Oxidized cellulose: 20 to 30 parts;

[0017] Nanocellulose: 2 to 6 parts;

[0018] Zeolite powder: 15 to 30 parts;

[0019] Calcium salt: 1 to 10 parts;

[0020] Polyethylene glycol: 0.3 parts to 1 part;

[0021] Chitosan: 0.3 to 1 part.

[0022] Preferably, the oxidized cellulose is oxidized cellulose with a carboxyl content of 0.1 mmol / g to 2 mmol / g.

[0023] Preferably, the nanocellulose has a length of 0.3 μm to 8 μm, a diameter of 1 nm to 50 nm, and a carboxyl content of 0.1 mmol / g to 2 mmol / g.

[0024] Preferably, the nanocellulose is obtained by treating plant fibers with TEMPO oxidation.

[0025] Preferably, the plant fiber is at least one of grass fiber, reed fiber, cotton fiber, bamboo fiber, hemp fiber, sugarcane fiber, and coniferous wood fiber.

[0026] Preferably, the zeolite powder has a particle size of 0.05 μm to 8 μm and a specific surface area of ​​300 m². 2 / g~2000m 2 / g.

[0027] Preferably, the calcium salt is at least one of calcium chloride, calcium bromide, calcium iodide, and calcium nitrate.

[0028] Preferably, the number average molecular weight of the polyethylene glycol is 4000g / mol-20000g / mol.

[0029] Preferably, the degree of deacetylation of the chitosan is 80%-95%.

[0030] Preferably, the thickness of the adsorptive paper is 0.1mm-2mm.

[0031] A preparation method of the adsorptive paper as described above comprises the following steps:

[0032] 1) Preparation of slurry A and slurry B:

[0033] Preparation of slurry A: zeolite powder is wet ball milled with water, and then calcium salt and polyethylene glycol are added and uniformly mixed to obtain slurry A;

[0034] Preparation of slurry B: oxidized cellulose and nanocellulose are dispersed in water to obtain slurry B;

[0035] 2) Uniformly mixing slurry A and slurry B to obtain slurry C;

[0036] 3) Chitosan is dissolved in an acetic acid solution, and then added to slurry C and uniformly mixed, followed by papermaking and molding to obtain the adsorptive paper.

[0037] Preferably, the wet ball milling in step 1) uses a planetary ball mill, the rotation speed of the planetary ball mill is 100rpm-500rpm, and the ball milling time is 1h-5h.

[0038] Preferably, the concentration of the acetic acid solution in step 3) is 0.5wt%-1.5wt%.

[0039] A packaging material comprising the adsorptive paper as described above.

[0040] The adsorptive paper of the present application has the advantages of high adsorption efficiency, excellent mechanical properties, uniform pore structure, good air permeability, etc., and when used as a packaging material, it can not only effectively adsorb the peculiar smell molecules emitted by durians, but also effectively prevent durians from ripening and deteriorating during transportation, and is suitable for the air transportation of durians.

[0041] Specifically:

[0042] 1) The adsorption type paper of the present application comprises a network structure formed by calcium ions, oxidized cellulose and nanocellulose, which not only can effectively intercept zeolite powder and has excellent loading capacity for zeolite powder, but also can provide sufficient tensile strength for the paper, in addition, the insertion of the oxidized cellulose in the paper retains part of the small pores of the paper and provides good flexibility and part of the tensile strength of the paper, finally makes the paper have high adsorption efficiency, excellent mechanical properties, uniform pore structure, good air permeability and other excellent properties;

[0043] 2) The preparation method of the adsorption type paper of the present application is simple, does not need large production equipment or precision production equipment, and the reaction condition is mild, which is suitable for large-scale industrial production;

[0044] 3) The adsorption type paper of the present application can be used for batch transportation of durians, which is beneficial to reduce the cost of air transportation of durians, and has low cost and high social and economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 Fig. 1 is a structural schematic diagram of an adsorption performance testing device in the present application.

[0046] Figure 2 Fig. 2 is a SEM diagram of the surface of the adsorption type paper of Examples 1-3 and Comparative Examples 1-3.

[0047] Figure 3 Fig. 3 is a SEM diagram of the cross section of the adsorption type paper of Examples 1-3 and Comparative Example 3. DETAILED DESCRIPTION

[0048] The present application will be further explained and described below in combination with specific examples.

[0049] Example 1:

[0050] An adsorption type paper, the composition of which is shown in the following table:

[0051] Table 1 Composition table of an adsorption type paper

[0052]

[0053]

[0054] Note: The nanocellulose is obtained by TEMPO oxidation method treatment of coniferous wood fibers.

[0055] The preparation method of the above adsorption type paper is as follows:

[0056] 1) Preparation of slurry A and slurry B:

[0057] Preparation of slurry A: zeolite powder was wet ball milled with water, the ball milling equipment was planetary ball mill, the weight ratio of zeolite powder, Zr02ball and water was 1:10:20, the rotation speed of planetary ball mill was 300 rpm, the ball milling time was 4 h, then the obtained zeolite suspension was stirred with anhydrous calcium chloride and polyethylene glycol for 30 min at a stirring speed of 450 rpm to obtain slurry A;

[0058] Preparation of slurry B: oxidized cellulose and nanocellulose were added into water, the amount of water was 100 times of the total weight of oxidized cellulose and nanocellulose, then the stirring speed was controlled at 500 rpm for 1 h to obtain slurry B;

[0059] 2) Slurry A and slurry B were mixed, and the stirring speed was controlled at 600 rpm for 1 h to obtain slurry C;

[0060] 3) Chitosan was dissolved in acetic acid solution with a concentration of 1 wt%, the weight ratio of chitosan and acetic acid solution was 1:100, then it was added into slurry C, and the stirring speed was controlled at 600 rpm for 0.5 h, then papermaking and molding were performed to obtain the adsorption type paper.

[0061] Example 2:

[0062] An adsorption type paper, the composition of which is shown in the following table:

[0063] Table 2 Composition table of an adsorption type paper

[0064]

[0065]

[0066] The preparation method of the above adsorption type paper is as follows:

[0067] 1) Preparation of slurry A and slurry B:

[0068] Preparation of slurry A: zeolite powder was wet ball milled with water, the ball milling equipment was planetary ball mill, the weight ratio of zeolite powder, Zr02ball and water was 1:20:50, the rotation speed of planetary ball mill was 300 rpm, the ball milling time was 4 h, then the obtained zeolite suspension was stirred with calcium chloride dihydrate and polyethylene glycol for 60 min at a stirring speed of 600 rpm to obtain slurry A;

[0069] Preparation of slurry B: oxidized cellulose and nanocellulose were added into water, the amount of water was 100 times of the total weight of oxidized cellulose and nanocellulose, then the stirring speed was controlled at 500 rpm for 1 h to obtain slurry B;

[0070] 2) Mix slurry A and slurry B, and stir for 1 h at 600 rpm to obtain slurry C;

[0071] 3) Dissolve chitosan in acetic acid solution with a concentration of 1 wt%, and the weight ratio of chitosan to acetic acid solution is 1:200, and then add to slurry C, and stir for 0.5 h at 600 rpm, and then perform papermaking and molding to obtain the adsorption type paper.

[0072] Example 3:

[0073] An adsorption type paper, except that the amount of calcium chloride dihydrate used in preparation is adjusted from "5 parts by weight" to "1 part by weight", and the rest is exactly the same as Example 2.

[0074] Comparative Example 1:

[0075] An adsorption type paper, except that no nanocellulose is added during preparation, and the rest is exactly the same as Example 2.

[0076] Comparative Example 2:

[0077] An adsorption type paper, except that the amount of calcium chloride dihydrate used in preparation is adjusted from "5 parts by weight" to "8 parts by weight", and no oxidized cellulose is added, and the rest is exactly the same as Example 2.

[0078] Comparative Example 3:

[0079] Adsorption type paper (Takarabussan's "deodorizing charcoal").

[0080] Performance test:

[0081] 1) The performance test data of the adsorption type paper of Examples 1-3 and Comparative Examples 1-3 are shown in the following table:

[0082] Table 3 Performance test data of adsorption type paper

[0083]

[0084]

[0085] Note:

[0086] Thickness: measured by paper thickness gauge.

[0087] Maximum load, maximum tensile stress and elastic modulus: tested by universal tensile testing machine (instron universal testing machine), sample width is 25 mm, and tensile rate is 10 mm / min.

[0088] Adsorption performance: 1 μL of ethanethiol was accurately taken by a microsyringe and placed in a 1000 mL headspace bottle, the bottle cap was quickly closed, and the bottle was left to stand for 1 h (until the ethanethiol was completely volatilized), then the concentration of ethanethiol in the headspace bottle was tested by a headspace gas chromatograph, and the function integral measured by the headspace gas chromatograph was recorded as C0; an adsorption performance testing device (structure diagram as shown in Figure 1

[0089] From Table 3, it can be seen that:

[0090] a) The adsorption performance of the adsorption type paper of Examples 1-3 for ethanethiol is very excellent, and the adsorption type paper of Examples 1-3 all has excellent mechanical properties;

[0091] b) The mechanical properties and adsorption performance of the adsorption type paper of Example 3 are slightly worse than those of the adsorption type paper of Examples 1 and 2, because: the addition amount of calcium salt in the adsorption type paper of Example 3 is reduced, the dispersion and condensation force of the whole system is reduced, which leads to a slight decrease in the mechanical properties of the paper, but the maximum tensile stress reaches 9.44 MPa ± 0.14 MPa, and the mechanical properties are still good enough, in addition, the reduction of calcium ions will lead to a decrease in the loading amount of zeolite powder in the paper, and the adsorption performance of the paper is slightly reduced, but the adsorption performance reaches 56.98%, and the adsorption performance is still good enough;

[0092] c) The adsorption type paper of Comparative Example 1 (without nanocellulose) has a decreased adsorption performance of 47.62% compared with the adsorption type paper of Comparative Example 2, and the maximum tensile stress is also reduced to 7.92 MPa ± 0.20 MPa, which shows that nanocellulose has an important contribution to the mechanical properties of the paper, especially the tensile properties and the adsorption performance;

[0093] d) The adsorption type paper of Comparative Example 2 (without oxidized cellulose) has a slight decrease in mechanical properties compared with the adsorption type paper of Comparative Example 2, and the adsorption performance is greatly reduced to 42.42%, which shows that oxidized cellulose has an important contribution to the adsorption performance of the paper; ​

[0094] e) The adsorptive paper of Comparative Example 3 is much worse than that of Comparative Example 2 in adsorption performance, which shows that the adsorptive paper of the present application is significantly better than the commercially available adsorptive paper.

[0095] 2) The adsorptive papers of Examples 1-3 and Comparative Examples 1-3 were cut into square shape with size of 0.8 cm x 0.8 cm, and then fixed on the surface of a metal carrier table with conductive glue, and then the zeolite distribution on the surface of the adsorptive paper and the microstructure of the adsorptive paper were observed by scanning electron microscope (SEM), and the SEM images obtained are shown in FIG. 2; Figure 2 The adsorptive papers of Examples 1-3 and Comparative Example 3 were cut by a quick cutter, and then the cross section was fixed on the side of a metal carrier table with conductive glue, and then the zeolite distribution on the cross section of the adsorptive paper and the microstructure of the adsorptive paper were observed by scanning electron microscope, and the SEM images obtained are shown in FIG. 3. Figure 3

[0096] From FIG. 2 and FIG. 3, it can be seen that: Figure 2 Figure 3

[0097] a) The surface of the adsorptive papers of Examples 1-3 does not have a large amount of zeolite powder, which shows that the zeolite powder is mainly loaded in the paper (the adsorptive paper of the present application has no powder dropping or powder feeling when touched), and the addition of polyethylene glycol and chitosan improves the uniformity of the paper and makes the surface partially film, and the wet ball milling enables the zeolite powder to be uniformly dispersed in the paper (although there are a small amount of concave or hole-like structures on the surface of the adsorptive paper, it can be seen that the zeolite powder fills and covers each concave or hole-like region);

[0098] b) The surface of the adsorptive papers of Examples 1-3 is very smooth and the thickness of the paper is uniform everywhere (which shows that the uniformity of the paper is good), and it can be observed that the inside of the adsorptive paper is filled with a large amount of zeolite powder, and the zeolite powder and the fibers together form the adsorptive paper (the inside of the paper is a layer-by-layer structure, and the layers of micron-sized oxidized cellulose are filled with zeolite powder);

[0099] c) The adsorptive paper of Comparative Example 1 (without nano-cellulose) can be observed to form larger agglomerates, which shows that the nano-cellulose not only strengthens the forming ability of the paper structure, but also plays a role in splitting the zeolite powder agglomerates by its own steric hindrance, and the zeolite powder agglomeration not only reduces the contact area between the zeolite powder and the gas to be adsorbed, but also causes the fibers to be not filled with zeolite powder, resulting in a large number of hole structures on the surface of the paper, which ultimately leads to the decrease of the adsorption performance of the paper;

[0100] ​​​d) The zeolite powder of the adsorption type paper of comparative example 2 (without oxidized cellulose) is dispersed uniformly, but almost no pore structure is observed on the surface of the paper, which makes it difficult for gas molecules to enter the interior of the paper, the effective contact area of the paper to the gas is reduced, and the adsorption performance is significantly reduced, which shows that the oxidized cellulose is necessary, and the steric hindrance of the oxidized cellulose can provide a small amount of pores for the gas to enter the interior of the paper and be effectively adsorbed;

[0101] e) The fibers in the adsorption type paper of comparative example 3 are not tightly packed, resulting in a large number of hole structures on the surface of the paper, and no adsorption material exists in the holes, so the gas can easily shuttle through such a large hole structure and easily pass through the paper, resulting in poor adsorption effect of the paper;

[0102] As can be seen from the above, the calcium salt, the oxidized cellulose and the nanocellulose in the adsorption type paper of the present application are essential, and the synergistic effect of the three significantly improves the forming effect and the gas adsorption performance of the paper.

[0103] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement methods and shall be included in the protection scope of the present application.

Claims

1. An absorbent paper, characterized in that, Includes the following components in parts by weight: Oxidized cellulose: 20 to 80 parts; Nanocellulose: 1 part to 20 parts; Zeolite powder: 10 to 60 parts; Calcium salts: 1 to 20 parts; Polyethylene glycol: 0.1 parts to 4 parts; Chitosan: 0.1 to 2 parts.

2. The absorbent paper according to claim 1, characterized in that: The oxidized cellulose is oxidized cellulose with a carboxyl content of 0.1 mmol / g to 2 mmol / g.

3. The absorbent paper according to claim 1, characterized in that: The nanocellulose has a length of 0.3 μm to 8 μm, a diameter of 1 nm to 50 nm, and a carboxyl content of 0.1 mmol / g to 2 mmol / g.

4. The absorbent paper according to any one of claims 1 to 3, characterized in that: The zeolite powder has a particle size of 0.05 μm to 8 μm and a specific surface area of ​​300 m². 2 / g~2000m 2 / g.

5. The absorbent paper according to any one of claims 1 to 3, characterized in that: The calcium salt is at least one of calcium chloride, calcium bromide, calcium iodide, and calcium nitrate.

6. The absorbent paper according to any one of claims 1 to 3, characterized in that: The number-average molecular weight of the polyethylene glycol is 4000 g / mol to 20000 g / mol.

7. The absorbent paper according to any one of claims 1 to 3, characterized in that: The degree of deacetylation of the chitosan is 80%–95%.

8. The absorbent paper according to any one of claims 1 to 3, characterized in that: The thickness of the absorbent paper is 0.1 mm to 2 mm.

9. A method for preparing absorbent paper as described in any one of claims 1 to 8, characterized in that, Includes the following steps: 1) Preparation of slurry A and slurry B: Preparation of slurry A: Zeolite powder is wet-milled with water, then calcium salt and polyethylene glycol are added and mixed evenly to obtain slurry A; Preparation of slurry B: Oxidized cellulose and nanocellulose were dispersed in water to obtain slurry B; 2) Mix slurry A and slurry B evenly to obtain slurry C; 3) Dissolve chitosan in acetic acid solution, add it to slurry C and mix well, then form and shape the paper to obtain absorbent paper.

10. A packaging material, characterized in that, It includes the absorbent paper as described in any one of claims 1 to 8.

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