High-barrier degradable material and preparation method thereof

Abstract

The invention relates to a high-barrier degradable material and a preparation method thereof, and belongs to the technical field of high polymer materials. The high-barrier degradable material is prepared by using 1, 4-succinic acid, 1, 4-butanediol, a catalyst and a self-made ester exchange modified monomer as raw materials, and the preparation method comprises the following steps: firstly, carrying out esterification polymerization on the 1, 4-succinic acid and excessive 1, 4-butanediol under the action of the catalyst, then adding the ester exchange modified monomer and the 1, 4-butanediol into a reaction container, and carrying out esterification polymerization on the obtained product to obtain the high-barrier degradable material. The high-barrier degradable material is obtained through ester exchange polymerization of 1, 4-butanediol, the preparation method of the high-barrier degradable material is simple, large-scale production is easy, and the prepared high-barrier degradable material has good mechanical property and gas barrier property, further has flame retardance and can be widely applied to the field of food packaging.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular, relates to a high-barrier degradable material and a preparation method thereof. Background Art

[0002] As a new type of fully biodegradable polymer material, PBS has received extensive attention and research in recent years. PBS, or polybutylene succinate, is an important biodegradable polymer made from aliphatic diol 1,4-butanediol and aliphatic dibasic acid 1,4-succinic acid through polycondensation. PBS has good biodegradability and can be completely degraded by microorganisms in nature after use, eventually generating carbon dioxide and water, without causing pollution to the environment. This feature gives PBS a significant advantage in reducing the impact of plastic waste on the environment.

[0003] However, PBS still has the disadvantage of poor gas barrier properties. As a packaging material, its barrier performance cannot meet the requirements of high barrier materials, which will cause the product in the package to be affected by oxygen or moisture and deteriorate. Therefore, PBS is now used in the field of packaging materials. Based on this, the present invention provides a method for preparing a high barrier degradable material. Summary of the invention

[0004] The object of the present invention is to provide a high-barrier biodegradable material and a preparation method thereof, so as to solve the problems mentioned in the above background technology.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A high barrier biodegradable material, comprising the following raw materials in parts by weight: 28.6-42.9 parts of ester exchange modified monomer, 118 parts of 1,4-succinic acid, 240-260 parts of 1,4-butanediol, and 2.2-2.8 parts of a catalyst;

[0007] A method for preparing a high barrier degradable material comprises the following steps:

[0008] The first step is to weigh the raw materials according to the mass fractions: 28.6-42.9 parts of ester exchange modified monomer, 118 parts of 1,4-succinic acid, 240-260 parts of 1,4-butanediol, and 2.2-2.8 parts of catalyst;

[0009] Step 2: Add 1,4-butanediol, 1,4-butanediol and a catalyst into a reaction container, introduce nitrogen into the reaction container to exhaust the air in the reaction container, and then perform esterification polymerization under nitrogen protection conditions;

[0010] The third step is to cool the reaction system to 170°C, then add the ester exchange modified monomer and all the remaining 1,4-butanediol in the raw materials into the reaction vessel, and carry out ester exchange polymerization under nitrogen protection. After the reaction is completed, cool the reaction system to room temperature to obtain a high barrier biodegradable material.

[0011] Furthermore, the catalyst is one of stannous octoate, stannous chloride, and tetrabutyl titanate.

[0012] Furthermore, the mass ratio of 1,4-butanediol used in the second step is 118 parts:200-220 parts.

[0013] Furthermore, the esterification polymerization in the second step is carried out at a temperature of 185-195° C. for 4 hours.

[0014] Furthermore, the conditions for the transesterification polymerization in the third step are to react at a temperature of 170°C for 6 hours, then raise the system temperature to 200-210°C and react for 1 hour, and then raise the system temperature to 225-235°C and react for 4 hours.

[0015] Furthermore, the preparation method of the transesterification modified monomer comprises the following steps:

[0016] Step 1, 2,5-furandicarboxaldehyde, dimethyl malonate, piperidine and anhydrous ethanol were mixed in a three-necked flask, magnetic stirring was turned on, and the mixture was reacted at room temperature for 3 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and then chromatographed on a silica gel column to obtain an intermediate 1;

[0017] Step 2, the intermediate 1, dimethyl phosphite, 1,5,7-triazabicyclo-[4.4.0]dec-5-ene, and anhydrous ethanol are mixed in a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is turned on, and the reaction is carried out at a temperature of 50-60° C. for 1 hour. After the reaction is completed, the solvent is removed by rotary evaporation, and the remaining solid is subjected to silica gel column chromatography to obtain the ester exchange modified monomer;

[0018] Furthermore, the dosage ratio of 2,5-furandicarboxaldehyde, dimethyl malonate, piperidine and anhydrous ethanol used in step 1 is 0.05 mol: 0.1 mol: 0.02-0.03 mol: 50-60 mL.

[0019] Furthermore, the dosage ratio of intermediate 1, dimethyl phosphite, 1,5,7-triazabicyclo-[4.4.0]dec-5-ene, and anhydrous ethanol used in step 2 is 0.04 mol: 0.08 mol: 0.016-0.024 mol: 40-50 mL.

[0020] Beneficial effects of the present invention:

[0021] 1) The present invention uses 1,4-butanediol, 1,4-butanediol, a catalyst, and a self-made ester exchange modified monomer as raw materials to prepare a high-barrier degradable material. The present invention first esterifies and polymerizes 1,4-butanediol and an excess of 1,4-butanediol under the action of a catalyst, and then adds the ester exchange modified monomer and 1,4-butanediol into a reaction container for ester exchange polymerization to obtain a high-barrier degradable material. The raw materials used in the preparation method of the present invention can be degraded by microorganisms, and the prepared high-barrier degradable material has a higher degree of crosslinking than PBS, and therefore has better mechanical properties and gas barrier properties, and better heat resistance.

[0022] 2) The present invention uses 2,5-furandicarboxaldehyde and dimethyl malonate as raw materials, utilizes the aldehyde group of 2,5-furandicarboxaldehyde and the active methylene group of dimethyl malonate to undergo Knoevenagel reaction to obtain an intermediate 1 with two double bonds, and then uses the intermediate 1 and dimethyl phosphite as raw materials, utilizes the double bond of the intermediate 1 and dimethyl phosphite to undergo Michael addition reaction to obtain an ester exchange modified monomer; the ester exchange modified monomer preparation method of the present invention has good selectivity, although there is also a double bond on the furan ring of the intermediate 1 in step 2, the furan ring has aromaticity, and therefore has the advantages of "easy substitution and difficult addition". Characteristics will not affect the selection of addition reaction. The ester exchange modified monomer of the present invention has four ester groups, which can undergo ester exchange reaction with PBS polymer monomer to copolymerize and modify PBS, introduce a rigid furan ring structure and a phosphate structure with flame retardant effect into the PBS chain, and improve the cross-linking degree of the PBS molecular chain, thereby improving the gas barrier property and flame retardant property of PBS. In addition, the ester exchange modified monomer of the present invention does not contain benzene ring and other difficult-to-degrade elements, and the furan ring and phosphate structure can be degraded by microorganisms in nature, so it will not affect the biodegradability of the modified PBS.

[0023] 3) The preparation method of the high-barrier degradable material of the present invention is simple and easy to scale up for production. The prepared high-barrier degradable material has good mechanical properties and gas barrier properties, and is also flame retardant, and can be widely used in the field of food packaging. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0025] Example 1

[0026] A transesterification modified monomer is prepared by the following steps:

[0027] Step 1, 0.05 mol 2,5-furandicarboxaldehyde, 0.1 mol dimethyl malonate, 0.02 mol piperidine, and 50 mL anhydrous ethanol were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 3 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and then subjected to silica gel column chromatography to obtain intermediate 1;

[0028] Step 2: Mix 0.04 mol intermediate 1, 0.08 mol dimethyl phosphite, 0.016 mol 1,5,7-triazabicyclo-[4.4.0]dec-5-ene, and 40 mL of anhydrous ethanol in a three-necked flask, install a condenser and a thermometer, turn on the magnetic stirring, and react at a temperature of 50° C. for 1 h. After the reaction is completed, the solvent is removed by rotary evaporation, and the remaining solid is subjected to silica gel column chromatography to obtain the ester exchange modified monomer.

[0029] Example 2

[0030] A transesterification modified monomer is prepared by the following steps:

[0031] Step 1, 0.05 mol 2,5-furandicarboxaldehyde, 0.1 mol dimethyl malonate, 0.025 mol piperidine, and 55 mL anhydrous ethanol were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 3 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and then subjected to silica gel column chromatography to obtain intermediate 1;

[0032] Step 2: Mix 0.04 mol intermediate 1, 0.08 mol dimethyl phosphite, 0.02 mol 1,5,7-triazabicyclo-[4.4.0]dec-5-ene, and 45 mL of anhydrous ethanol in a three-necked flask, install a condenser and a thermometer, turn on the magnetic stirring, and react at a temperature of 55 ° C for 1 hour. After the reaction is completed, the solvent is removed by rotary evaporation, and the remaining solid is subjected to silica gel column chromatography to obtain the ester exchange modified monomer.

[0033] Example 3

[0034] A transesterification modified monomer is prepared by the following steps:

[0035] Step 1, 0.05 mol 2,5-furandicarboxaldehyde, 0.1 mol dimethyl malonate, 0.03 mol piperidine, and 60 mL anhydrous ethanol were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 3 hours. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and then subjected to silica gel column chromatography to obtain intermediate 1;

[0036] Step 2: Mix 0.04 mol intermediate 1, 0.08 mol dimethyl phosphite, 0.024 mol 1,5,7-triazabicyclo-[4.4.0]dec-5-ene, and 50 mL of anhydrous ethanol in a three-necked flask, install a condenser and a thermometer, turn on the magnetic stirring, and react at a temperature of 60° C. for 1 h. After the reaction is completed, the solvent is removed by rotary evaporation, and the remaining solid is subjected to silica gel column chromatography to obtain the ester exchange modified monomer.

[0037] Example 4

[0038] A high barrier biodegradable material, comprising the following raw materials in parts by weight: 28.6 parts of the transesterification modified monomer obtained in Example 1, 118 parts of 1,4-butanediol, 240 parts of 1,4-butanediol, and 2.2 parts of stannous octoate;

[0039] A method for preparing a high barrier degradable material comprises the following steps:

[0040] The first step is to weigh 28.6 parts of the ester exchange modified monomer obtained in Example 1, 118 parts of 1,4-butanediol, 240 parts of 1,4-butanediol, and 2.2 parts of stannous octoate according to their mass fractions;

[0041] Step 2: Add 1,4-butanediol, 1,4-butanediol and stannous octoate into a reaction container, introduce nitrogen into the reaction container to exhaust the air in the reaction container, and then react for 4 hours for esterification polymerization under nitrogen protection and temperature of 185°C. The mass ratio of 1,4-butanediol used in this step is 118 parts: 200 parts.

[0042] The third step is to cool the reaction system to 170°C, then add the ester exchange modified monomer obtained in Example 1 and all the remaining 1,4-butanediol in the raw materials into the reaction container, and react for 6 hours at 170°C under nitrogen protection, then increase the system temperature to 200°C and react for 1 hour, then increase the system temperature to 225°C and react for 4 hours. After the reaction, cool the reaction system to room temperature to obtain a high barrier biodegradable material.

[0043] Example 5

[0044] A high barrier biodegradable material, comprising the following raw materials in parts by weight: 35.75 parts of the transesterification modified monomer obtained in Example 2, 118 parts of 1,4-butanediol, 250 parts of 1,4-butanediol, and 2.5 parts of stannous chloride;

[0045] A method for preparing a high barrier degradable material comprises the following steps:

[0046] The first step is to weigh 35.75 parts of the ester exchange modified monomer obtained in Example 2, 118 parts of 1,4-butanediol, 250 parts of 1,4-butanediol, and 2.5 parts of stannous chloride according to their mass fractions;

[0047] Step 2: Add 1,4-butanediol, 1,4-butanediol and stannous chloride into a reaction container, introduce nitrogen into the reaction container to exhaust the air in the reaction container, and then react for 4 hours for esterification polymerization under nitrogen protection and a temperature of 190° C., and the mass ratio of 1,4-butanediol used in this step is 118 parts: 210 parts by mass;

[0048] The third step is to cool the reaction system to 170°C, then add the ester exchange modified monomer obtained in Example 2 and all the remaining 1,4-butanediol in the raw materials into the reaction container, and react for 6 hours at 170°C under nitrogen protection, then increase the system temperature to 205°C and react for 1 hour, then increase the system temperature to 230°C and react for 4 hours. After the reaction, cool the reaction system to room temperature to obtain a high barrier biodegradable material.

[0049] Example 6

[0050] A high barrier biodegradable material, comprising the following raw materials in parts by weight: 42.9 parts of the transesterification modified monomer obtained in Example 3, 118 parts of 1,4-succinic acid, 260 parts of 1,4-butanediol, and 2.8 parts of tetrabutyl titanate;

[0051] A method for preparing a high barrier degradable material comprises the following steps:

[0052] The first step is to weigh 42.9 parts of the ester exchange modified monomer obtained in Example 3, 118 parts of 1,4-butanediol, 260 parts of 1,4-butanediol, and 2.8 parts of tetrabutyl titanate according to their mass fractions;

[0053] Step 2: Add 1,4-butanediol, 1,4-butanediol and tetrabutyl titanate into a reaction container, introduce nitrogen into the reaction container to exhaust the air in the reaction container, and then react for 4 hours for esterification polymerization under nitrogen protection and a temperature of 195°C. The mass ratio of 1,4-butanediol used in this step is 118 parts: 220 parts.

[0054] The third step is to cool the reaction system to 170°C, then add the ester exchange modified monomer obtained in Example 3 and all the remaining 1,4-butanediol in the raw materials into the reaction container, and react for 6 hours at 170°C under nitrogen protection, then raise the system temperature to 210°C and react for 1 hour, then raise the system temperature to 235°C and react for 4 hours. After the reaction, cool the reaction system to room temperature to obtain a high barrier biodegradable material.

[0055] Comparative Example 1

[0056] A high barrier biodegradable material, comprising the following raw materials in parts by weight: 118 parts of 1,4-succinic acid, 260 parts of 1,4-butanediol, and 2.8 parts of tetrabutyl titanate;

[0057] A method for preparing a high barrier degradable material comprises the following steps:

[0058] The first step is to weigh the raw materials according to their mass fractions: 118 parts of 1,4-butanediol, 260 parts of 1,4-butanediol, and 2.8 parts of tetrabutyl titanate;

[0059] Step 2: Add 1,4-butanediol, 1,4-butanediol and tetrabutyl titanate into a reaction container, introduce nitrogen into the reaction container to exhaust the air in the reaction container, and then react for 4 hours for esterification polymerization under nitrogen protection and a temperature of 195°C. The mass ratio of 1,4-butanediol used in this step is 118 parts: 220 parts.

[0060] The third step is to cool the reaction system to 170°C, then add all the remaining 1,4-butanediol in the raw materials in the reaction container, and react for 6 hours at 170°C under nitrogen protection, then raise the system temperature to 210°C and react for 1 hour, then raise the system temperature to 235°C and react for 4 hours. After the reaction, cool the reaction system to room temperature to obtain a high barrier biodegradable material.

[0061] Comparative Example 2

[0062] This comparative example is a commercially available PBS packaging film.

[0063] After being made into films, a high barrier degradable material in Examples 4-6 and Comparative Example 1 was tested together with the commercially available PBS packaging film in Comparative Example 2 for performance. The gas barrier properties were tested with reference to the national standard GB / T19789-2005 "Oxygen permeability test for plastic films and sheets for packaging materials - coulometer test method", and the flame retardant properties were tested with reference to the national standard GB / T 2408-2021 "Determination of combustion performance of plastics - horizontal and vertical methods". The test results are shown in Table 1:

[0064] Table 1

[0065]

[0066] It can be seen from Table 1 that the high barrier degradable material of the present invention in Examples 4-6 has good gas barrier properties and flame retardancy compared with the commercially available PBS packaging film, while the high barrier degradable material in Comparative Example 1 has poor gas barrier properties and does not have a flame retardant effect. The reason is that the ester exchange modified monomer of the present invention is not used for modification during preparation. In summary, the high barrier degradable material of the present invention has good gas barrier effect and flame retardancy, and can be widely used in the field of food packaging.

[0067] A high barrier degradable material and a preparation method thereof provided by the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enables any technician in the field to practice the present invention, including the manufacture and use of any device or system, and the implementation of any combination method. It should be pointed out that for ordinary technicians in this technical field, the present invention can also be improved and modified in a number of ways without departing from the principles of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention can be used in combination with each other in any way. The fact that these combinations are not exhaustively described in this specification is only for the purpose of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A high barrier degradable material, characterized in that: The method comprises the following raw materials in parts by weight: 28.6-42.9 parts of ester exchange modified monomer, 118 parts of 1,4-succinic acid, 240-260 parts of 1,4-butanediol, and 2.2-2.8 parts of catalyst; Wherein, the transesterification modified monomer is prepared by the following steps: Step 1, 2,5-furandicarboxaldehyde, dimethyl malonate, piperidine and anhydrous ethanol are mixed in a container, stirred evenly, and reacted at room temperature for 3 hours to obtain intermediate 1; Step 2: Mix the intermediate 1, dimethyl phosphite, 1,5,7-triazabicyclo-[4.4.0]dec-5-ene and anhydrous ethanol in a container, stir evenly, and react at a temperature of 50-60° C. for 1 hour to obtain the ester exchange modified monomer.

2. A high barrier degradable material according to claim 1, characterized in that: The amount ratio of 2,5-furandicarboxaldehyde, dimethyl malonate, piperidine and anhydrous ethanol used in step 1 is 0.05 mol: 0.1 mol: 0.02-0.03 mol: 50-60 mL.

3. The high barrier degradable material according to claim 1, characterized in that: The amount ratio of intermediate 1, dimethyl phosphite, 1,5,7-triazabicyclo-[4.4.0]dec-5-ene and anhydrous ethanol used in step 2 is 0.04 mol: 0.08 mol: 0.016-0.024 mol: 40-50 mL.

4. A method for preparing a high barrier degradable material according to any one of claims 1 to 3, characterized in that: The following steps are involved: The first step is to weigh the raw materials according to the mass fractions: 28.6-42.9 parts of ester exchange modified monomer, 118 parts of 1,4-succinic acid, 240-260 parts of 1,4-butanediol, and 2.2-2.8 parts of catalyst; Step 2: Add 1,4-butanediol, 1,4-butanediol and a catalyst into a reaction container, introduce nitrogen into the reaction container to exhaust the air in the reaction container, and then perform esterification polymerization under nitrogen protection conditions; The third step is to cool the reaction system to 170°C, then add the ester exchange modified monomer and all the remaining 1,4-butanediol in the raw materials into the reaction vessel, and carry out ester exchange polymerization under nitrogen protection. After the reaction is completed, cool the reaction system to room temperature to obtain a high barrier biodegradable material.

5. The method for preparing a high barrier degradable material according to claim 4, characterized in that: The catalyst is one of stannous octoate, stannous chloride and tetrabutyl titanate.

6. The method for preparing a high barrier degradable material according to claim 4, characterized in that: In terms of mass fractions, the mass fraction ratio of 1,4-butanediol used in the second step is 118 parts: 200-220 parts.

7. The method for preparing a high barrier degradable material according to claim 4, characterized in that: The conditions for the esterification polymerization in the second step are to react at a temperature of 185-195°C for 4 hours.

8. The method for preparing a high barrier degradable material according to claim 4, characterized in that: The conditions of the ester exchange polymerization in the third step are to react at a temperature of 170°C for 6 hours, then raise the system temperature to 200-210°C and react for 1 hour, and then raise the system temperature to 225-235°C and react for 4 hours.

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