Full-biodegradable paper-plastic composite paper cup and preparation method thereof

Abstract

The invention discloses a full-biodegradable paper-plastic composite paper cup and a preparation method thereof. The preparation method of the full-biodegradable paper-plastic composite paper cup comprises the following steps: (1) adding modified konjac glucomannan, beewax, PHA, glycerol and Tween 80 into deionized water, heating and stirring to obtain a composite film solution; and (2) coating the surface of a food-grade paperboard with the composite film liquid through a coating machine, drying, cutting, and preparing the paper cup, so as to obtain the full-biodegradable paper-plastic composite paper cup. The composite paper cup obtained by the method has excellent full biodegradability, mechanical property and hydrophobicity, and a sample is tested according to a standard, the hydrophobic angle is 151.3 degrees, and the relative biological decomposition rate is greater than or equal to 90%.

Description

Technical Field

[0001] The invention belongs to the technical field of composite paper cups, and in particular relates to a fully biodegradable paper-plastic composite paper cup and a preparation method thereof. Background Art

[0002] As people's requirements for the quality of life are getting higher and higher, the quality and environmental protection of paper cups as consumables in daily life are receiving more and more attention. Fully biodegradable paper-plastic composite paper cups meet consumers' demand for high-quality, environmentally friendly products and have good market prospects and social value. At the same time, the government's support for the environmental protection industry has been continuously increased, providing policy guarantees for the development of biodegradable paper-plastic composite paper cups. With the advancement of science and technology, the research and application of biodegradable materials have developed rapidly, providing new ideas for solving environmental problems. Therefore, fully biodegradable paper-plastic composite paper cups are expected to become an important choice to replace traditional plastic products.

[0003] Patent CN 105966014 A discloses a fully biodegradable composite material, which is composed of the following components in weight: 30-90% paper, 10-70% fully biodegradable film, and the gram weight of paper is 20-120g / cm 2 The weight of the fully biodegradable film is 5-80g / cm 2 The composite material has the functions of water absorption and oil resistance on one side, and water resistance and oil absorption on the other side. The material is mainly used in disposable fully biodegradable paper bags, paper boxes, paper cups, paper bowls, tablecloths, masks, medical pads, aviation, catering tableware, etc., making catering products safer, healthier and more environmentally friendly. However, the biodegradability, waterproofness and mechanical properties of the composite material produced by this process need to be improved. Summary of the invention

[0004] The object of the present invention is to provide a fully biodegradable paper-plastic composite paper cup and a preparation method thereof, so as to solve the technical problems of poor biodegradability, waterproofness and mechanical properties of composite materials in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention provides a fully biodegradable paper-plastic composite paper cup, which is composed of the following components in parts by weight: 88-91 parts of food-grade paperboard, 1-2 parts of beeswax, 5-6 parts of PHA, 1-2 parts of modified konjac glucomannan, 0.5-1 parts of glycerol and 0.5-1 parts of Tween 80.

[0007] Preferably, the method for preparing the modified konjac glucomannan comprises the following steps:

[0008] S1: Add phosphoric acid to deionized water, mix well, adjust pH with hydrochloric acid, add konjac glucomannan during stirring, and react in a water bath;

[0009] S2: After the reaction is completed, washing is performed, and anhydrous ethanol is added to perform a dehydration reaction. After the reaction, filtering, drying, crushing, and sieving are performed to obtain modified konjac glucomannan.

[0010] In the above process, phosphoric acid is used to modify konjac glucomannan to improve the hydrophobicity of konjac glucomannan. The synthesis process of modified konjac glucomannan is as follows:

[0011]

[0012] Preferably, in S1, the purity of phosphoric acid is 98%, the dosage ratio of phosphoric acid, deionized water and konjac glucomannan is (0.5-1) mL: (10-20) mL: (4.5-9.0) g, the concentration of hydrochloric acid is 1 mol / L, the pH is adjusted to 2, the water bath temperature is 60-70° C., and the reaction time is 0.5-2 h.

[0013] Preferably, in S2, the number of washings is 2-5 times, the dehydration reaction time is 10-12 hours, the drying temperature is 40-50°C, the drying time is 8-10 hours, and the sieved particle size is 60-80 mesh.

[0014] Preferably, the method for preparing the fully biodegradable paper-plastic composite paper cup comprises the following steps:

[0015] Step (1): adding PHA, modified konjac glucomannan, beeswax, glycerol and Tween 80 to deionized water, stirring evenly, heating and stirring in a water bath until the liquid is fully swollen, and obtaining a composite membrane liquid;

[0016] Step (2): coating the composite film liquid onto the surface of food-grade paperboard through a coating machine, drying, cutting, and making cups to obtain fully biodegradable paper-plastic composite paper cups.

[0017] Preferably, in step (1), the water bath heating temperature is 70-80° C., and the stirring speed is 300-400 rpm.

[0018] Preferably, in step (2), the drying temperature is 100-110° C. and the drying time is 0.3-0.5 h.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0020] 1. The present invention first utilizes phosphoric acid to modify konjac glucomannan so that the modified konjac glucomannan obtained has excellent hydrophobicity, then utilizes modified konjac glucomannan, beeswax, PHA, glycerine and Tween 80 to prepare composite film liquid, and the composite film liquid is evenly coated on the paperboard surface to obtain a hydrophobic outer film with excellent hydrophobic effect, and the paper-plastic composite paper cup obtained by the method has excellent full biodegradability and hydrophobicity, solves the environmental pollution caused by the difficulty of degradation of plastic products, thereby improving the environmental protection and durable life of the product.

[0021] 2. The present invention modifies konjac glucomannan with phosphoric acid to change its chemical structure and introduces phosphoric acid groups to make it hydrophobic. When the modified konjac glucomannan is mixed with beeswax, PHA, glycerol and Tween 80, a dense film is formed on the surface of the composite paperboard, which effectively prevents moisture from entering the interior of the paper cup, keeps the composite paper cup dry and increases its reusability. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The following embodiments of the present invention are used:

[0024] Anhydrous ethanol was purchased from Jinan Shengrui Chemical Co., Ltd., CAS No.: 64-17-5;

[0025] Phosphoric acid was purchased from Shandong Taixi Chemical Co., Ltd., CAS No.: 7664-38-2;

[0026] Hydrochloric acid was purchased from Jiangsu Xuhong Environmental Protection Technology Co., Ltd., CAS No.: 7647-01-0;

[0027] Konjac glucomannan was purchased from Shaanxi Muyun Biotechnology Co., Ltd., CAS number: 37220-17-0;

[0028] Beeswax was purchased from Shaanxi Tangyao Biotechnology Co., Ltd., CAS number: 8012-89-3;

[0029] Glycerin was purchased from Shandong Huaye Trading Co., Ltd., CAS No.: 56-81-5;

[0030] Tween 80 was purchased from Guangzhou Tianjia Biotechnology Co., Ltd., CAS number: 9005-65-6.

[0031] Example 1

[0032] The present embodiment discloses a method for preparing modified konjac glucomannan, comprising the following steps:

[0033] S1: Add 0.5 mL of 98% pure phosphoric acid to 15 mL of deionized water, mix well, adjust pH to 2 with 1 mol / L hydrochloric acid, add 4.5 g of konjac glucomannan during stirring, and react in a water bath at 70°C for 2 h;

[0034] S2: After the reaction, wash three times, add anhydrous ethanol for dehydration for 12 hours, filter, dry at 50°C for 10 hours, crush, and pass through an 80-mesh sieve to obtain modified konjac glucomannan.

[0035] This embodiment discloses a fully biodegradable paper-plastic composite paper cup, which is composed of the following ingredients in parts by weight: 89 parts of food-grade paperboard, 1 part of beeswax, 6 parts of PHA, 2 parts of modified konjac glucomannan, 1 part of glycerol and 1 part of Tween 80.

[0036] This embodiment discloses a method for preparing a fully biodegradable paper-plastic composite paper cup, comprising the following steps:

[0037] Step (1): adding modified konjac glucomannan, PHA, beeswax, glycerol and Tween 80 to deionized water, stirring evenly, heating in a water bath at 75° C., and stirring at 400 rpm until the liquid is fully swollen to obtain a composite membrane liquid;

[0038] Step (2): coating the composite film liquid onto the surface of food-grade paperboard through a coating machine, drying, cutting, and making cups to obtain fully biodegradable paper-plastic composite paper cups.

[0039] Example 2

[0040] The present embodiment discloses a method for preparing modified konjac glucomannan, comprising the following steps:

[0041] S1: Add 0.8 mL of 98% pure phosphoric acid to 10 mL of deionized water, mix well, adjust pH to 2 with 1 mol / L hydrochloric acid, add 5 g of konjac glucomannan during stirring, and react in a water bath at 70°C for 2 h;

[0042] S2: After the reaction, wash three times, add anhydrous ethanol for dehydration for 12 hours, filter, dry at 50°C for 10 hours, crush, and pass through an 80-mesh sieve to obtain modified konjac glucomannan.

[0043] This embodiment discloses a fully biodegradable paper-plastic composite paper cup, which is composed of the following ingredients in parts by weight: 89 parts of food-grade paperboard, 1 part of beeswax, 6 parts of PHA, 2 parts of modified konjac glucomannan, 1 part of glycerol and 1 part of Tween 80.

[0044] This embodiment discloses a method for preparing a fully biodegradable paper-plastic composite paper cup, comprising the following steps:

[0045] Step (1): adding modified konjac glucomannan, PHA, beeswax, glycerol and Tween 80 to deionized water, stirring evenly, heating in a water bath at 75° C., and stirring at 400 rpm until the liquid is fully swollen to obtain a composite membrane liquid;

[0046] Step (2): coating the composite film liquid onto the surface of food-grade paperboard through a coating machine, drying, cutting, and making cups to obtain fully biodegradable paper-plastic composite paper cups.

[0047] Example 3

[0048] The present embodiment discloses a method for preparing modified konjac glucomannan, comprising the following steps:

[0049] S1: Add 0.5 mL of 98% pure phosphoric acid to 15 mL of deionized water, mix well, adjust pH to 2 with 1 mol / L hydrochloric acid, add 4.5 g of konjac glucomannan during stirring, and react in a water bath at 70°C for 2 h;

[0050] S2: After the reaction, wash three times, add anhydrous ethanol for dehydration for 12 hours, filter, dry at 50°C for 10 hours, crush, and pass through an 80-mesh sieve to obtain modified konjac glucomannan.

[0051] This embodiment discloses a fully biodegradable paper-plastic composite paper cup, which is composed of the following ingredients in parts by weight: 88 parts of food-grade paperboard, 2 parts of beeswax, 6 parts of PHA, 2 parts of modified konjac glucomannan, 1 part of glycerol and 1 part of Tween 80.

[0052] This embodiment discloses a method for preparing a fully biodegradable paper-plastic composite paper cup, comprising the following steps:

[0053] Step (1): adding modified konjac glucomannan, PHA, beeswax, glycerol and Tween 80 to deionized water, stirring evenly, heating in a water bath at 75° C., and stirring at 400 rpm until the liquid is fully swollen to obtain a composite membrane liquid;

[0054] Step (2): coating the composite film liquid onto the surface of food-grade paperboard through a coating machine, drying, cutting, and making cups to obtain fully biodegradable paper-plastic composite paper cups.

[0055] Example 4

[0056] The present embodiment discloses a method for preparing modified konjac glucomannan, comprising the following steps:

[0057] S1: Add 0.5 mL of 98% pure phosphoric acid to 15 mL of deionized water, mix well, adjust pH to 2 with 1 mol / L hydrochloric acid, add 4.5 g of konjac glucomannan during stirring, and react in a water bath at 70°C for 2 h;

[0058] S2: After the reaction, wash three times, add anhydrous ethanol for dehydration for 12 hours, filter, dry at 50°C for 10 hours, crush, and pass through an 80-mesh sieve to obtain modified konjac glucomannan.

[0059] This embodiment discloses a fully biodegradable paper-plastic composite paper cup, which is composed of the following ingredients in parts by weight: 90 parts of food-grade paperboard, 1 part of beeswax, 5 parts of PHA, 2 parts of modified konjac glucomannan, 1 part of glycerol and 1 part of Tween 80.

[0060] This embodiment discloses a method for preparing a fully biodegradable paper-plastic composite paper cup, comprising the following steps:

[0061] Step (1): adding modified konjac glucomannan, PHA, beeswax, glycerol and Tween 80 to deionized water, stirring evenly, heating in a water bath at 75° C., and stirring at 400 rpm until the liquid is fully swollen to obtain a composite membrane liquid;

[0062] Step (2): coating the composite film liquid onto the surface of food-grade paperboard through a coating machine, drying, cutting, and making cups to obtain fully biodegradable paper-plastic composite paper cups.

[0063] Example 5

[0064] The present embodiment discloses a method for preparing modified konjac glucomannan, comprising the following steps:

[0065] S1: Add 0.5 mL of 98% pure phosphoric acid to 15 mL of deionized water, mix well, adjust pH to 2 with 1 mol / L hydrochloric acid, add 4.5 g of konjac glucomannan during stirring, and react in a water bath at 70°C for 2 h;

[0066] S2: After the reaction, wash three times, add anhydrous ethanol for dehydration for 12 hours, filter, dry at 50°C for 10 hours, crush, and pass through an 80-mesh sieve to obtain modified konjac glucomannan.

[0067] This embodiment discloses a fully biodegradable paper-plastic composite paper cup, which is composed of the following ingredients in parts by weight: 90 parts of food-grade paperboard, 2 parts of beeswax, 5 parts of PHA, 2 parts of modified konjac glucomannan, 0.5 parts of glycerol and 0.5 parts of Tween 80.

[0068] This embodiment discloses a method for preparing a fully biodegradable paper-plastic composite paper cup, comprising the following steps:

[0069] Step (1): adding modified konjac glucomannan, PHA, beeswax, glycerol and Tween 80 to deionized water, stirring evenly, heating in a water bath at 75° C., and stirring at 400 rpm until the liquid is fully swollen to obtain a composite membrane liquid;

[0070] Step (2): coating the composite film liquid onto the surface of food-grade paperboard through a coating machine, drying, cutting, and making cups to obtain fully biodegradable paper-plastic composite paper cups.

[0071] Comparative Example 1

[0072] Comparative Example 1 Compared with Example 1, in the process of preparing the modified konjac glucomannan in Comparative Example 3, phosphoric acid was not added, and other conditions remained unchanged.

[0073] Comparative Example 2

[0074] Comparative Example 2 Compared with Example 1, in the process of preparing the fully biodegradable paper-plastic composite paper cup in Comparative Example 4, no beeswax was added, and other conditions remained unchanged.

[0075] Comparative Example 3

[0076] Comparative Example 3 Compared with Example 1, in the process of preparing the fully biodegradable paper-plastic composite paper cup in Comparative Example 3, modified konjac glucomannan glycerol is not added, and other conditions remain unchanged.

[0077] Experimental example

[0078] The properties of the fully biodegradable paper-plastic composite paper cups prepared in Examples 1-5 and Comparative Examples 1-3 were tested.

[0079] The contact angle of the sample was measured according to ASTM D724-99, and the degradation performance of the sample was measured according to GB / T 39951-2021. The test results are shown in Table 1:

[0080] Table 1

[0081] project Contact angle / ° Relative biodegradation rate / % Example 1 151.3 96 Example 2 148.2 93 Example 3 147.1 94 Example 4 148.9 92 Example 5 146.9 90 Comparative Example 1 126.8 86 Comparative Example 2 128.1 84 Comparative Example 3 124.7 83

[0082] From the test results in Table 1, it can be seen that the composite paper cups prepared in Examples 1-5 of the present invention have excellent biodegradability and hydrophobicity. From the comparison between Comparative Example 1 and Examples 1-5, it can be seen that the addition of phosphoric acid can effectively improve the hydrophobicity and biodegradability of the composite paper cup; from the comparison between Comparative Example 2 and Examples 1-5, it can be seen that the addition of beeswax can effectively improve the hydrophobicity and biodegradability of the composite paper cup; from the comparison between Comparative Example 3 and Examples 1-5, it can be seen that the addition of modified konjac glucomannan glycerol can effectively improve the hydrophobicity and biodegradability of the composite paper cup.

[0083] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0084] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Fully biodegradable paper-plastic composite paper cup, characterized in that: The invention comprises the following ingredients in parts by weight: 88-91 parts of food-grade paperboard, 1-2 parts of beeswax, 5-6 parts of PHA, 1-2 parts of modified konjac glucomannan, 0.5-1 parts of glycerol and 0.5-1 parts of Tween 80.

2. The fully biodegradable paper-plastic composite paper cup according to claim 1, characterized in that: The preparation method of the modified konjac glucomannan comprises the following steps: S1: Add phosphoric acid to deionized water, mix well, adjust pH with hydrochloric acid, add konjac glucomannan during stirring, and react in a water bath; S2: After the reaction is completed, washing is performed, and anhydrous ethanol is added to perform a dehydration reaction. After the reaction, filtering, drying, crushing, and sieving are performed to obtain modified konjac glucomannan.

3. The fully biodegradable paper-plastic composite paper cup according to claim 2, characterized in that: In the S1, the purity of phosphoric acid is 98%, the dosage ratio of phosphoric acid, deionized water and konjac glucomannan is (0.5-1) mL: (10-20) mL: (4.5-9.0) g, the concentration of hydrochloric acid is 1 mol / L, the pH is adjusted to 2, the water bath temperature is 60-70° C., and the reaction time is 0.5-2 h.

4. The method for preparing a fully biodegradable paper-plastic composite paper cup according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step (1): adding modified konjac glucomannan, beeswax, PHA, glycerol and Tween 80 to deionized water, stirring evenly, heating and stirring in a water bath until the liquid is fully swollen, and obtaining a composite membrane liquid; Step (2): coating the composite film liquid onto the surface of food-grade paperboard through a coating machine, drying, cutting, and preparing paper cups to obtain fully biodegradable paper-plastic composite paper cups.

5. The method for preparing a fully biodegradable paper-plastic composite paper cup according to claim 4, characterized in that: In the step (1), the water bath heating temperature is 70-80° C. and the stirring speed is 300-400 rpm.

6. The method for preparing a fully biodegradable paper-plastic composite paper cup according to claim 4, characterized in that: In the step (2), the drying temperature is 100-110° C. and the drying time is 0.3-0.5 h.

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