Use of brine solutions in the degradation of cellulose acetate

Abstract

The application discloses a use of a brine solution in degrading cellulose acetate, and by simply immersing a cigarette filter which is difficult to degrade, cigarette filter production waste, waste cellulose acetate filter membrane or cellulose acetate fabric and the like in the brine solution, the biodegradability of the cigarette filter and the like can be remarkably improved, or the cellulose acetate fiber can be converted into cellulose fiber. The treatment agent used in the application for degrading cellulose acetate is simple in composition, safe and efficient, and provides a popular and practically valuable method for promoting degradation of the cigarette filter and the like and reducing pollutants in actual life, and can be practically applied to garbage cans in cities and waste treatment in families.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of environmental chemistry and material chemistry, and relates to a use of a salt water solution in degrading cellulose acetate. BACKGROUND

[0002] Cellulose acetate is a product obtained by acetylation of cellulose, and is often used as a cigarette filter. Since the hydroxyl groups on the cellulose chain are replaced by acetyl groups, cellulose acetate is more hydrophobic than pure cellulose, and it is difficult for microorganisms to adhere thereto. In addition, the acetyl groups mask the enzyme action sites, making it difficult for cellulose acetate to be biodegraded as easily as cellulose. Therefore, cigarette filters cannot be effectively biodegraded. Currently, the method widely used in industry to degrade cigarette filters is to add nano-titanium dioxide, but recent studies have shown that nano-titanium dioxide is carcinogenic, and therefore its use has been banned by the European Union. In order to overcome the above technical problems, researchers have developed methods for encapsulating phosphoric acid, sulfate ester, phosphate ester, sulfate, organic acid, etc. in cigarette filters to promote the hydrolytic degradation performance of the cigarette filters. However, the above methods are not conducive to the stability of the cigarette filters during storage. At the same time, due to the problems of migration and insufficient stability of small molecules, and the fact that no relevant research has been conducted on whether the chemical substances added to promote the hydrolytic degradation performance of the cigarette filters will cause health hazards during use, it is also necessary to consider the complex processing method and potential hazards of adding acidic or basic additives during the formation of the cigarette filters, which makes the actual use and industrial production of cigarette filters a long and rigorous evaluation process. Therefore, the development of a cheap, safe, easy-to-achieve and life-like treatment agent for degrading cigarette filters can enable it to be quickly and effectively applied in the industrial production of cigarette filters. SUMMARY

[0003] To solve the above problems, the present application provides a use of a salt water solution in degrading cellulose acetate, wherein the salt water solution comprises: an inorganic salt and water.

[0004] According to an embodiment of the present application, the inorganic salt is at least one of NaHCO3, Na2CO3, K2CO3 and K3PO4.

[0005] According to an embodiment of the present application, the mass concentration of the inorganic salt in the salt water solution is 1-10%. As an example, the mass concentration of the inorganic salt can be 1%, 2%, 4%, 8% or 10%.

[0006] According to an embodiment of the present application, the cellulose acetate can be derived from a cigarette filter, cigarette filter production waste, discarded cellulose acetate filter membrane or cellulose acetate fabric.

[0007] Those skilled in the art can understand that the cigarette filter can be a pre-smoking or post-smoking cigarette filter.

[0008] The present application also provides a method for degrading cellulose acetate by the above-mentioned salt solution, comprising soaking cellulose acetate in the salt solution and compost degradation.

[0009] According to embodiments of the present application, the cellulose acetate and the salt solution both have the definitions and selections described above.

[0010] According to embodiments of the present application, the soaking temperature is 20-100℃; exemplary temperatures are 20℃, 40℃, 60℃, 80℃, and 100℃.

[0011] According to embodiments of the present application, the soaking time is 2-48h; exemplary times are 2h, 4h, 8h, 12h, 24h, and 48h.

[0012] According to embodiments of the present application, the compost degradation conditions include a temperature of 50-70℃ (e.g., 60℃), a humidity of 30-60% (e.g., 50%), and a degradation time of 20-50 days (e.g., 28 days).

[0013] The present application also provides use of the above-mentioned salt solution in the preparation of regenerated cellulose fibers.

[0014] The present application also provides a method for preparing regenerated cellulose fibers, comprising soaking cellulose acetate (e.g., derived from cigarette filters, cigarette filter production waste, discarded cellulose acetate membranes, or cellulose acetate fabrics) in a salt solution, removing the product, and obtaining the regenerated cellulose fibers.

[0015] According to embodiments of the present application, the soaking temperature is 60-100℃; exemplary temperatures are 60℃, 80℃, and 100℃.

[0016] According to embodiments of the present application, the soaking time is 4-48h; exemplary times are 2h, 4h, 8h, 12h, 24h, and 48h.

[0017] According to embodiments of the present application, the method for preparing regenerated cellulose fibers further comprises washing and drying the product after removal.

[0018] The present application also provides use of the regenerated cellulose fibers prepared by the above-mentioned method in paper. Preferably, the regenerated cellulose fibers are used as papermaking additives.

[0019] The regenerated cellulose fibers of the present application can enhance paper strength when used as papermaking additives.

[0020] The present application also provides a paper containing the above-mentioned regenerated cellulose fibers.

[0021] According to an embodiment of the present application, the mass percentage of the regenerated cellulose fiber in the paper is 3-20% (for example, 10%).

[0022] According to an embodiment of the present application, the mechanical property of the paper is 4-7 MPa (for example, 6.5 MPa).

[0023] The present application also provides a method for preparing the above-mentioned paper, comprising mixing the paper pulp with the regenerated cellulose fiber, and suction filtering into paper.

[0024] According to an embodiment of the present application, the concentration of the paper pulp is 2-10% (for example, 5%).

[0025] According to an embodiment of the present application, the mass percentage of the regenerated cellulose fiber in the total solid content of the paper pulp is 5-15% (for example, 10%).

[0026] The present application has the following beneficial effects:

[0027] The present application surprisingly finds that the acetic cellulose substance or waste (for example, cigarette filter, cigarette filter production waste, waste acetic cellulose filter membrane or acetic cellulose fabric, etc.) which is difficult to degrade can be significantly improved in biodegradability by simply soaking in a salt water solution, or the acetic cellulose fiber is converted into cellulose fiber. Thus, not only the harm of these substances or wastes to human health can be reduced, but also these substances or wastes can be converted into available cellulose fiber, so as to realize the effective utilization of production and living wastes. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 For the observation of the industrial compost degradation process of the cigarette filter in Comparative Example 1.

[0029] Figure 2 For the mass loss in the industrial compost degradation process of the cigarette filter in Comparative Example 1.

[0030] Figure 3 For the observation of the industrial compost degradation process of the cigarette filter after the treatment of the Na2CO3 aqueous solution in Example 1.

[0031] Figure 4 For the mass loss in the industrial compost degradation process of the cigarette filter after the treatment of the Na2CO3 aqueous solution in Example 1.

[0032] Figure 5 For the observation of the industrial compost degradation process of the cigarette filter after the treatment of the K2CO3 aqueous solution in Example 3.

[0033] Figure 6The industrial compost degradation process of the cigarette filter treated with K3PO4 aqueous solution in Example 5 was observed.

[0034] Figure 7 The industrial compost degradation process of the cigarette filter treated with NaHCO3 aqueous solution in Example 6 was observed.

[0035] Figure 8 The infrared spectra of the cigarette filter before and after treatment with Na2CO3 aqueous solution in Example 7.

[0036] Figure 9 The mechanical property test results of the regenerated cellulose fiber obtained by treating the cigarette filter with Na2CO3 aqueous solution in Example 8 for reinforcing paper. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be further described in detail below in combination with specific examples. It should be understood that the following examples are only illustratively described and explained, and should not be interpreted as limiting the scope of protection of the present application. Any technology achieved based on the above description of the present application is covered within the scope of protection intended by the present application.

[0038] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0039] Comparative Example 1

[0040] After removing the surface paper layer (i.e., cellulose acetate) of the cigarette filter, a degradation experiment was conducted under industrial compost conditions (temperature: 60°C, humidity: 50%). The cigarette filter was taken out every 7 days and photographed. At the same time, one of the cigarette filters was washed with deionized water and then dried in a blast oven at 80°C for 24 h before weighing. The results are shown in Figs. Figure 1 and Figure 2 As can be seen from the figures, the appearance and weight of the cigarette filter did not change significantly within 28 days, indicating that the biodegradability of the cigarette filter was very poor.

[0041] Example 1

[0042] After removing the surface paper layer (i.e., cellulose acetate) of the cigarette filter, the cigarette filter was soaked in a 4% Na2CO3 aqueous solution at room temperature for 48 h. The cigarette filter was taken out and a degradation experiment was conducted under industrial compost conditions (temperature: 60°C, humidity: 50%). The cigarette filter was taken out every 7 days and photographed. At the same time, one of the cigarette filters was washed and dried before weighing. The results are shown in Figs. Figure 3 and Figure 4 As can be seen from the figures, the biodegradability of the cigarette filter treated with Na2CO3 aqueous solution was significantly improved, and it gradually degraded and was almost completely degraded within 28 days.

[0043] Example 2

[0044] After removing the surface paper layer (i.e. cellulose acetate) of the cigarette filter, it was soaked in 8% Na2CO3 aqueous solution at room temperature for 2h, taken out, and subjected to degradation experiment under industrial composting conditions (temperature: 60°C, humidity: 50%) for 28 days. Every 7 days, the cigarette filter was taken out, photographed, and washed and dried for weighing. The degradation of the cigarette filter treated with Na2CO3 aqueous solution was significantly improved, and it gradually degraded and almost completely degraded in 28 days.

[0045] Example 3

[0046] After removing the surface paper layer (i.e. cellulose acetate) of the cigarette filter, it was soaked in 4% K2CO3 aqueous solution at room temperature for 12h, taken out, and subjected to degradation experiment under industrial composting conditions (temperature: 60°C, humidity: 50%) for 28 days. Every 7 days, the cigarette filter was taken out, photographed, and washed and dried for weighing. The results are shown in Figure 5 Fig. 2. As can be seen from the figure, the degradation of the cigarette filter treated with K2CO3 aqueous solution was significantly improved, and it gradually degraded and almost completely degraded in 28 days.

[0047] Example 4

[0048] After removing the surface paper layer (i.e. cellulose acetate) of the cigarette filter, it was soaked in 6% K2CO3 aqueous solution at room temperature for 6h, taken out, and subjected to degradation experiment under industrial composting conditions (temperature: 60°C, humidity: 50%) for 28 days. Every 7 days, the cigarette filter was taken out, photographed, and washed and dried for weighing. The degradation of the cigarette filter treated with K2CO3 aqueous solution was significantly improved, and it gradually degraded and almost completely degraded in 28 days.

[0049] Example 5

[0050] After removing the surface paper layer (i.e. cellulose acetate) of the cigarette filter, it was soaked in 8% K3PO4 aqueous solution at room temperature for 2h, taken out, and subjected to degradation experiment under industrial composting conditions (temperature: 60°C, humidity: 50%) for 28 days. Every 7 days, the cigarette filter was taken out, photographed, and washed and dried for weighing. The results are shown in Figure 6 Fig. 5. As can be seen from the figure, the degradation of the cigarette filter treated with K3PO4 aqueous solution was significantly improved, and it gradually degraded and almost completely degraded in 28 days.

[0051] Example 6

[0052] The cigarette filter after removing the surface paper layer (i.e. cellulose acetate) was soaked in 4% NaHCO3 aqueous solution at 100°C for 8h, taken out, and subjected to degradation experiment under industrial composting conditions (temperature: 60°C, humidity: 50%) for 28 days. Every 7 days, the cigarette filter was taken out, photographed, and washed and dried to determine the weight. The results are shown in Figure 7 From the figure, it can be seen that the degradation of the cigarette filter treated with NaHCO3 aqueous solution was significantly improved, and it gradually degraded and almost completely degraded in 28 days.

[0053] Example 7

[0054] The cigarette filter after removing the surface paper layer (i.e. cellulose acetate) was soaked in 8% Na2CO3 aqueous solution at 60°C for 12h, taken out, washed with water, and dried to obtain regenerated cellulose fibers.

[0055] The infrared spectrum of the regenerated cellulose fiber material obtained in this example is shown in Figure 8 Compared with the spectrum of the cellulose acetate before treatment, the carbonyl stretching vibration peak at 1740cm-1 completely disappeared, thereby proving that the regenerated cellulose fiber was successfully obtained in this example. -1

[0056] Example 8

[0057] The cigarette filter after removing the surface paper layer (i.e. cellulose acetate) was soaked in 2% Na2CO3 aqueous solution at 100°C for 12h, taken out, washed with water, and dried to obtain regenerated cellulose fibers. The regenerated cellulose fibers were mixed with the paper pulp, and the regenerated cellulose fibers accounted for 10% of the total solid content of the paper pulp, and the pulp slurry concentration was 5%. The paper was made by suction filtration.

[0058] The mechanical properties of the paper prepared in this example were tested. Specifically, the paper was cut into a rectangular sample of 10mm x 100mm, and placed at 25°C and 30% humidity for 48h. Then, the tensile test was performed on a universal tensile testing machine at a tensile rate of 0.5mm / min. The results are shown in Figure 9 From the figure, it can be seen that the mechanical properties of the paper (10% regenerated cellulose fiber reinforced paper) prepared in this example were better than those of the paper (unreinforced paper) without adding regenerated cellulose fibers under the same conditions.

[0059] The above describes the embodiments of the present application. However, the present application is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.​

Claims

1. A method of degrading cellulose acetate with a brine solution, characterized by, The method comprises soaking cellulose acetate in a salt water solution, compost degradation; The salt water solution comprises: an inorganic salt and water; The inorganic salt is selected from at least one of Na2CO3 and K3PO4; The mass concentration of the inorganic salt in the salt water solution is 4-10%; The temperature of the soaking is 20-100 C; the time of the soaking is 2-48 h; The conditions for compost degradation include: temperature 50-70 C, humidity 30-60%, degradation time 20-28 days; The cellulose acetate is derived from a cigarette filter, cigarette filter production waste, waste cellulose acetate filter membrane or cellulose acetate fabric.

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