A high-barrier degradable material and preparation method thereof

Abstract

The present invention relates to a high-barrier degradable material and a preparation method thereof, belonging to the technical field of polymer materials. The present invention uses 1,4-succinic acid, 1,4-butanediol, a catalyst, and a self-made transesterification modified monomer as raw materials to prepare a high-barrier degradable material. The present invention first esterifies and polymerizes 1,4-succinic acid and an excess of 1,4-butanediol under the action of a catalyst, and then adds the transesterification modified monomer and 1,4-butanediol into a reaction vessel for transesterification polymerization to obtain a high-barrier degradable material. 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, is flame retardant, and can be widely used in 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, fully biodegradable polymer material, PBS has received extensive attention and research in recent years. PBS, or polybutylene succinate, is an important biodegradable polymer made through the polycondensation reaction of the aliphatic diol 1,4-butanediol and the aliphatic dibasic acid 1,4-butanedioic acid. PBS exhibits excellent biodegradability and is completely degraded by microorganisms in nature, ultimately producing carbon dioxide and water, without causing environmental pollution. This characteristic gives PBS a significant advantage in reducing the environmental impact of plastic waste.

[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 products in the package to be affected by oxygen or moisture and deteriorate. Therefore, PBS is currently 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 degradable 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 an ester exchange-modified monomer, 118 parts of 1,4-butanediol, 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 28.6-42.9 parts of the transesterification modified monomer, 118 parts of 1,4-butanediol, 240-260 parts of 1,4-butanediol, and 2.2-2.8 parts of the catalyst according to their mass fractions;

[0009] Step 2: Add 1,4-butanediol, 1,4-butanediol, and a catalyst into a reaction vessel, introduce nitrogen into the reaction vessel to exhaust the air in the reaction vessel, 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, the reaction system is cooled 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 to 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 started, and the mixture was reacted at room temperature for 3 hours. After the reaction, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and purified by silica gel column chromatography to obtain intermediate 1;

[0017] Step 2: Mix the intermediate 1, dimethyl phosphite, 1,5,7-triazabicyclo-[4.4.0]dec-5-ene, and anhydrous ethanol in a three-necked flask, install a condenser and a thermometer, turn on magnetic stirring, and react 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 transesterification 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 usage 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 homemade 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 vessel for ester exchange polymerization to obtain a high-barrier degradable material. The raw materials used in the preparation method of the present invention can all be degraded by microorganisms, and the prepared high-barrier degradable material has a higher degree of cross-linking 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 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 intermediate 1 in step 2, the furan ring is aromatic and therefore has the characteristics 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 and 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 increase the cross-linking degree of the PBS molecular chain, thereby improving the gas barrier performance and flame retardant performance of PBS. In addition, the ester exchange modified monomer of the present invention does not contain benzene rings and other difficult-to-degrade elements. The furan ring and phosphate structure can be degraded by microorganisms in nature, and therefore 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 embodiments described 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 making any creative efforts shall fall 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 of anhydrous ethanol were mixed in a three-necked flask, magnetic stirring was turned on, and the mixture was reacted at room temperature for 3 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and purified by 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 magnetic stirring, and react at a temperature of 50 ° 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.

[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 of anhydrous ethanol were mixed in a three-necked flask, magnetic stirring was turned on, and the mixture was reacted at room temperature for 3 h. After the reaction was completed, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and purified by 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 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 of anhydrous ethanol were mixed in a three-necked flask, magnetic stirring was turned on, and the mixture was reacted at room temperature for 3 h. After the reaction, the solvent was removed by rotary evaporation, and the remaining solid was washed with deionized water and purified by 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 magnetic stirring, and react at a temperature of 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.

[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] Step 1: Weigh 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 according to their mass fractions;

[0041] Step 2: 1,4-butanediol, 1,4-butanediol, and stannous octoate were added to a reaction vessel, nitrogen was introduced into the reaction vessel to exhaust the air in the reaction vessel, and then the reaction was carried out for 4 hours under nitrogen protection and a temperature of 185° C. for esterification polymerization. The mass ratio of 1,4-butanediol to 1,4-butanediol used in this step was 118 parts:200 parts by mass.

[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 vessel, and react at 170°C under nitrogen protection for 6 hours. Then, the system temperature is raised to 200°C and reacted for 1 hour, and then the system temperature is raised to 225°C and reacted for 4 hours. After the reaction is completed, the reaction system is cooled 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] Step 1: Weigh 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 according to their mass fractions;

[0047] Step 2: 1,4-butanediol, 1,4-butanediol, and stannous chloride were added to a reaction vessel, and nitrogen was introduced into the reaction vessel to exhaust the air in the reaction vessel. The reaction was then carried out under nitrogen protection at 190° C. for 4 hours for esterification polymerization. The mass ratio of 1,4-butanediol to 1,4-butanediol used in this step was 118 parts:210 parts.

[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 vessel, and react for 6 hours at 170°C under nitrogen protection, then raise the system temperature to 205°C and react for 1 hour, then raise the system temperature to 230°C and react for 4 hours. After the reaction is completed, 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-butanediol, 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] Step 1: Weigh 42.9 parts of the transesterification 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: 1,4-butanediol, 1,4-butanediol, and tetrabutyl titanate were added to a reaction vessel, and nitrogen was introduced into the reaction vessel to exhaust the air in the reaction vessel. The reaction was then carried out under nitrogen protection at a temperature of 195° C. for 4 hours for esterification polymerization. The mass ratio of 1,4-butanediol to 1,4-butanediol used in this step was 118 parts:220 parts by mass.

[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 vessel, 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 is completed, 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-butanediol, 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 118 parts of 1,4-butanediol, 260 parts of 1,4-butanediol, and 2.8 parts of tetrabutyl titanate according to their mass fractions;

[0059] Step 2: 1,4-butanediol, 1,4-butanediol, and tetrabutyl titanate were added to a reaction vessel, and nitrogen was introduced into the reaction vessel to exhaust the air in the reaction vessel. The reaction was then carried out under nitrogen protection at a temperature of 195° C. for 4 hours for esterification polymerization. The mass ratio of 1,4-butanediol to 1,4-butanediol used in this step was 118 parts:220 parts by mass.

[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 vessel, and react at 170°C under nitrogen protection for 6 hours. Then, raise the system temperature to 210°C and react for 1 hour, and then raise the system temperature to 235°C and react for 4 hours. After the reaction is completed, 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] The high-barrier biodegradable materials in Examples 4-6 and Comparative Example 1 were made into films and the commercially available PBS packaging film in Comparative Example 2 were tested for performance. The gas barrier properties were tested according to the national standard GB / T19789-2005 "Plastic Film and Sheeting for Packaging Materials - Oxygen Permeability - Coulometer Method" and the flame retardancy was tested according to the national standard GB / T 2408-2021 "Plastics - Determination of Combustion Properties - Horizontal and Vertical Methods". The test results are shown in Table 1:

[0064] Table 1

[0065]

[0066] As can be seen from Table 1, the high-barrier degradable material of the present invention in Examples 4-6 has good gas barrier properties and flame retardancy compared to 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] The above is a detailed introduction to a high barrier degradable material and a preparation method thereof provided by the present invention. 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 way, 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 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 combined with each other in any way. The fact that these combinations are not exhaustively described in this specification is simply for the sake 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 transesterification modified monomer, 118 parts of 1,4-butanediol, 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: Mix 2,5-furandicarboxaldehyde, dimethyl malonate, piperidine, and anhydrous ethanol in a container, stir evenly, and react 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 transesterification modified monomer.

2. The 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 28.6-42.9 parts of the transesterification modified monomer, 118 parts of 1,4-butanediol, 240-260 parts of 1,4-butanediol, and 2.2-2.8 parts of the catalyst according to their mass fractions; Step 2: Add 1,4-butanediol, 1,4-butanediol, and a catalyst into a reaction vessel, introduce nitrogen into the reaction vessel to exhaust the air in the reaction vessel, 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, the reaction system is cooled 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 parts, the mass 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 esterification polymerization in the second step is carried out 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: In the third step, the transesterification polymerization was carried out at 170° C. for 6 h, followed by raising the system temperature to 200-210° C. for 1 h, and then raising the system temperature to 225-235° C. for 4 h.

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