PBAT copolymer resin composition and preparation method thereof

Abstract

The invention relates to the technical field of polymerization of degradable high polymer materials, in particular to a PBAT copolymer resin composition and a preparation method thereof.The PBAT copolymer resin composition comprises 20%-33% of a component A, 20%-33% of a component B, 44%-59% of a component C, 0.2%-5% of a component D and a required amount of auxiliaries; in the preparation method, in a high-purity nitrogen atmosphere, uniformly stirring and mixing the component A, the component B and the component C in required amount to obtain mixed slurry, and performing primary and secondary esterification reaction on the mixed slurry to obtain an esterification product; and adding a required component D into the esterification product, adding an auxiliary agent, carrying out a condensation polymerization reaction to reach a specified melt index, and then carrying out water-cooling curing, pelletizing and drying treatment to obtain the PBAT copolymer resin composition, the obtained PBAT copolymer resin composition has low hardness and strong toughness, and the limitation of the existing PBAT resin application is broken through.

Description

Technical Field

[0001] The present invention relates to the technical field of biodegradable polymer material polymerization, and is a PBAT copolymer resin composition and a preparation method thereof. Background Art

[0002] Polybutylene terephthalate-co-adipate (PBAT) is a polymer that combines the properties of PBA (polybutylene adipate) and PBT (polybutylene terephthalate). It has good mechanical properties, as well as good heat and impact resistance. The ester bond characteristics in its structure make it biodegradable and will completely decompose in home composting without leaving any toxic residues. When PBAT is placed in the compost, it decomposes significantly faster than plastics, making it an excellent substitute for toxic or hazardous materials such as plastics and other non-biodegradable plastics.

[0003] As people's environmental awareness increases, the market demand for biodegradable plastics and their products continues to rise. However, traditional PBAT products have certain defects. When PBAT is injected, the product hardness (above 85A) is relatively high and the toughness is insufficient. The application effect is not good in some injection molding fields (soft shell packaging, mobile phone cases, etc.), which hinders the development of this resin material. In order to solve the above problems, modification processing methods such as physical blending are usually used to reduce the hardness of the resin and improve the toughness, but this method is costly, and the secondary processing materials are easy to degrade, which has a great impact on the back-end products.

[0004] Therefore, it is very necessary to study and invent a new type of PBAT copolymer resin composition and its preparation method. Summary of the invention

[0005] The present invention provides a PBAT copolymer resin composition and a preparation method thereof, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of existing PBAT injection molded products such as high hardness, insufficient toughness and limited application fields.

[0006] One of the technical solutions of the present invention is achieved through the following measures: the raw materials include, by mole percentage, 20% to 33% of component A, 20% to 33% of component B, 44% to 59% of component C, 0.2% to 5% of component D and a required amount of additives, wherein component A is terephthalic acid or terephthalic acid glycol ester, component B is adipic acid, component C is 1,4-butanediol, and component D is one or more of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone and polycaprolactone diol.

[0007] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The above-mentioned auxiliary agents include catalysts, antioxidants, stabilizers, and cross-linking agents, wherein the catalyst is one or more of a titanium catalyst, a germanium catalyst, an aluminum catalyst, and a magnesium catalyst; the antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 1098, antioxidant 445, antioxidant 1425, and antioxidant 1222; the stabilizer is one or more of triphenyl phosphate, disodium hydrogen phosphate, tricalcium phosphate, trisodium phosphate, and triethyl phosphate; and the cross-linking agent is one or more of tartaric acid, malic acid, citric acid, glycerol, pentaerythritol, and polyether triol.

[0008] The above-mentioned PBAT copolymer resin composition is prepared according to the following steps: The first step is to uniformly mix the required amounts of component A, component B, and component C under a high-purity nitrogen atmosphere to obtain a mixed slurry; The second step is to heat the mixed slurry to carry out esterification reaction to obtain an esterification product; The third step is to add the required amount of component D to the esterification product, mix them evenly, and obtain a mixed melt; The fourth step is to subject the mixed melt to an esterification reaction again to obtain a prepolymer; The fifth step is to add a required amount of additives to the prepolymer to carry out polycondensation reaction to obtain a fluid PBAT copolymer resin composition; The sixth step is to subject the fluid PBAT copolymer resin composition to water cooling, solidification, pelletizing, and drying to obtain a PBAT copolymer resin composition.

[0009] In the above second step, the reaction temperature is raised to 150°C to 200°C, stayed for 10 minutes to 30 minutes, and then continued to be raised to 220°C to 240°C.

[0010] In the fourth step, the reaction temperature is 220° C. to 260° C., and the residence time is 5 minutes to 15 minutes.

[0011] In the fifth step, the reaction pressure is 10 Pa to 200 Pa, the reaction temperature is 230° C. to 260° C., and when the reaction is finished, the melt index is specified to be 3 g / 10 min to 10 g / 10 min.

[0012] The second technical solution of the present invention is achieved by the following measures: A method for preparing a PBAT copolymer resin composition comprises the following steps: The first step is to uniformly mix the required amounts of component A, component B, and component C under a high-purity nitrogen atmosphere to obtain a mixed slurry; The second step is to heat the mixed slurry to carry out esterification reaction to obtain an esterification product; The third step is to add the required amount of component D to the esterification product, mix them evenly, and obtain a mixed melt; The fourth step is to subject the mixed melt to an esterification reaction again to obtain a prepolymer; The fifth step is to add a required amount of additives to the prepolymer to carry out polycondensation reaction to obtain a fluid PBAT copolymer resin composition; The sixth step is to subject the fluid PBAT copolymer resin composition to water cooling, solidification, pelletizing, and drying to obtain a PBAT copolymer resin composition.

[0013] The following is a further optimization and / or improvement of the second technical solution of the above invention: In the above second step, the reaction temperature is raised to 150°C to 200°C, stayed for 10 minutes to 30 minutes, and then continued to be raised to 220°C to 240°C.

[0014] In the fourth step, the reaction temperature is 220° C. to 260° C., and the residence time is 5 minutes to 15 minutes.

[0015] In the fifth step, the reaction pressure is 10 Pa to 200 Pa, the reaction temperature is 230° C. to 260° C., and when the reaction is finished, the melt index is specified to be 3 g / 10 min to 10 g / 10 min.

[0016] The PBAT copolymer resin composition of the present invention is synthesized by four-component melt copolymerization or block copolymerization, which is more difficult to polymerize and produces more by-products. Some additives are added to inhibit side reactions to obtain a PBAT copolymer resin composition with low strength and high toughness, thereby reducing the cost of the back-end modified products. DETAILED DESCRIPTION

[0017] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art; the percentages in the present invention are all mass percentages unless otherwise specified.

[0018] The present invention will be further described below in conjunction with embodiments: Embodiment 1: The raw materials of the PBAT copolymer resin composition are calculated according to the theoretical yield of the composition, and include, by mole percentage, 20% to 33% of component A, 20% to 33% of component B, 44% to 59% of component C, 0.2% to 5% of component D and the required amount of additives, wherein component A is terephthalic acid or terephthalic acid glycol ester, component B is adipic acid, component C is 1,4-butanediol, and component D is one or more of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone and polycaprolactone diol.

[0019] Introducing component D during the polymerization of PBAT resin and changing the type, dosage and addition stage of component D can effectively control the molecular chain structure and further adjust the material properties, so that the hardness of the PBAT resin composition is significantly reduced and the toughness is significantly improved, thereby reducing the cost of the back-end modified products. At the same time, it expands the application areas of PBAT resin so that it can be used in soft shell packaging, children's toys and other fields.

[0020] Example 2: As an optimization of the above example, the auxiliary agent includes a catalyst, an antioxidant, a stabilizer, and a cross-linking agent, wherein the catalyst is one or more of a titanium-based catalyst, a germanium-based catalyst, an aluminum-based catalyst, and a magnesium-based catalyst; the antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 1098, antioxidant 445, antioxidant 1425, and antioxidant 1222; the stabilizer is one or more of triphenyl phosphate, disodium hydrogen phosphate, tricalcium phosphate, trisodium phosphate, and triethyl phosphate; and the cross-linking agent is one or more of tartaric acid, malic acid, citric acid, glycerol, pentaerythritol, and polyether triol.

[0021] The amount of catalyst, antioxidant, stabilizer and cross-linking agent added is calculated based on the theoretical output of the composition, and the amount of auxiliary agent components added is 0.005% to 0.2% by mass percentage.

[0022] The PBAT copolymer resin composition described in the present invention is a four-component product synthesized by melt copolymerization or block copolymerization. The polymerization is more difficult and produces more by-products. Therefore, according to production needs, additives need to be added to inhibit side reactions. According to production needs, defoamers, colorants, fluorescent whitening agents, and plasticizers may also be added.

[0023] Example 3: As an optimization of the above example, the following steps were followed to prepare: The first step is to uniformly mix the required amounts of component A, component B, and component C under a high-purity nitrogen atmosphere to obtain a mixed slurry; The second step is to heat the mixed slurry to carry out esterification reaction to obtain an esterification product; The third step is to add the required amount of component D to the esterification product, mix them evenly, and obtain a mixed melt; The fourth step is to subject the mixed melt to an esterification reaction again to obtain a prepolymer; The fifth step is to add a required amount of additives to the prepolymer to carry out polycondensation reaction to obtain a fluid PBAT copolymer resin composition; The sixth step is to subject the fluid PBAT copolymer resin composition to water cooling, solidification, pelletizing, and drying to obtain a PBAT copolymer resin composition.

[0024] As required, the purity of high-purity nitrogen is 99.999%; component D can also be added during the pulping process.

[0025] In the present invention, the A component terephthalic acid and the C component 1,4-butanediol react to generate butylene terephthalate units, the weight content T% of the butylene terephthalate units in the PBAT copolymer resin composition is 25wt% to 60wt%, the melt index of the PBAT copolymer resin composition is 3g / 10min to 10g / 10min, the hardness is 70A to 85A, the tensile strength is 5MPa to 20MPa, and the elongation at break is 700% or more.

[0026] The melt index of the PBAT copolymer resin composition is tested according to ISO 1133 standard at a temperature of 190°C and a load of 2.16 kg. The Shore hardness (A) is tested according to ASTM D-2240. The tensile strength is tested according to ISO 527 standard, a standard A-type spline of 10 mm*4 mm, a gauge length of 50 mm, and a pulling speed of 50 mm / min at room temperature. The elongation at break is tested according to ISO 527 standard, a standard A-type spline of 10 mm*4 mm, a gauge length of 50 mm, and a pulling speed of 50 mm / min at room temperature.

[0027] Example 4: As an optimization of the above example, in the second step, the reaction temperature is raised to 150°C to 200°C, stayed for 10 minutes to 30 minutes, and then continued to be raised to 220°C to 240°C.

[0028] Example 5: As an optimization of the above example, in the fourth step, the reaction temperature is 220°C to 260°C, and the residence time is 5 minutes to 15 minutes.

[0029] The esterification water of the esterification reaction is removed as needed, and the reaction is terminated when the conversion rate of the esterification reaction reaches 80% to 99%.

[0030] Example 6: As an optimization of the above example, in the fifth step, the reaction pressure is 10Pa to 200Pa, the reaction temperature is 230°C to 260°C, and at the end of the reaction, the specified melt index is 3g / 10min to 10g / 10min.

[0031] The test conditions of the above melt index are: temperature 190° C., load 2.16 kg.

[0032] Embodiment 7: The preparation method of the PBAT copolymer resin composition comprises the following steps: The first step is to uniformly mix the required amounts of component A, component B, and component C under a high-purity nitrogen atmosphere to obtain a mixed slurry; The second step is to heat the mixed slurry to carry out esterification reaction to obtain an esterification product; The third step is to add the required amount of component D to the esterification product, mix them evenly, and obtain a mixed melt; The fourth step is to subject the mixed melt to an esterification reaction again to obtain a prepolymer; The fifth step is to add a required amount of additives to the prepolymer to carry out polycondensation reaction to obtain a fluid PBAT copolymer resin composition; The sixth step is to subject the fluid PBAT copolymer resin composition to water cooling, solidification, pelletizing, and drying to obtain a PBAT copolymer resin composition.

[0033] Example 8: The PBAT copolymer resin composition is prepared according to the following steps: In the first step, 2.3 kg of terephthalic acid, 2.32 kg of adipic acid, and 3.48 kg of 1,4-butanediol were mixed and stirred uniformly under a high-purity nitrogen atmosphere to obtain a mixed slurry; The second step is to heat the mixed slurry to a temperature of 145°C to 165°C, hold for 15 minutes, and then continue to heat to 230°C to perform an esterification reaction to obtain an esterification product. The third step is to add 0.31 kg of polyethylene glycol to the esterification product and mix them evenly to obtain a mixed melt; Step 4: The mixed melt temperature is maintained at 230°C for 10 minutes, and an esterification reaction is performed again to obtain a prepolymer; The fifth step is to add 6.5398g of tetrabutyl titanate, 13.0797g of antioxidant 1010, 2.3543g of triphenyl phosphate, and 2.4197g of glycerol to the prepolymer, control the pressure at 60Pa to 100Pa, and perform a polycondensation reaction at a temperature of 235°C to obtain a fluid PBAT copolymer resin composition; In the sixth step, the fluid PBAT copolymer resin composition is subjected to water cooling solidification, pelletizing, and drying treatment to obtain a PBAT copolymer resin composition sample 1.

[0034] Example 9: 2.3 kg of terephthalic acid, 2.32 kg of adipic acid, 3.48 kg of 1,4-butanediol, 0.62 kg of polyethylene glycol, 6.8513 g of tetrabutyl titanate, 13.7025 g of antioxidant 1010, 13.7025 g of antioxidant 1076, 2.4665 g of triphenyl phosphate, and 2.5350 g of glycerol were prepared according to the preparation method of Example 8 to obtain Sample 2.

[0035] Example 10: 2.3 kg of terephthalic acid, 2.32 kg of adipic acid, 3.48 kg of 1,4-butanediol, 0.62 kg of polypropylene glycol, 6.8513 g of tetrabutyl titanate, 13.7025 g of antioxidant 1076, 13.7025 g of antioxidant 168, 2.4665 g of triphenyl phosphate and 2.5350 g of glycerol were prepared according to the preparation method of Example 8 to obtain sample 3.

[0036] Example 11: 2.3 kg of terephthalic acid, 2.32 kg of adipic acid, 3.48 kg of 1,4-butanediol, 0.31 kg of polypropylene glycol and 0.93 kg of polytetramethylene glycol, 7.4741 g of tetrabutyl titanate, 14.9482 g of antioxidant 445, 2.6907 g of triphenyl phosphate and 1.4948 g of pentaerythritol were prepared according to the preparation method of Example 8 to obtain sample 4.

[0037] Example 12: 2.3 kg of terephthalic acid, 2.32 kg of adipic acid, 3.48 kg of 1,4-butanediol, 1.25 kg of polytetramethylene glycol, 7.4741 g of tetrabutyl titanate, 14.9482 g of antioxidant 1010, 14.9482 g of antioxidant 168, 2.6907 g of triphenyl phosphate and 1.4948 g of pentaerythritol were prepared according to the preparation method of Example 8 to obtain sample 5.

[0038] Comparative Example 1: The difference from Example 8 is that polyethylene glycol and antioxidant 1076 are not added, and 2.3 kg of terephthalic acid, 2.32 kg of adipic acid, 3.48 kg of 1,4-butanediol, 6.2284 g of tetrabutyl titanate, 12.4569 g of antioxidant 1010, 2.2422 g of triphenyl phosphate, and 2.3045 g of glycerol are added according to the preparation method of Example 8 to obtain Sample 6.

[0039] The PBAT copolymer resin compositions obtained in Examples 8 to 12 and the PBAT resin composition obtained in Comparative Example 1 were subjected to the following performance parameter test and analysis: Hue: Use the American hunterColor flex EZ (original import) colorimeter. Test method: Dry 50g sample in a drying oven at 45℃ to 55℃ for 4 hours, take it out and cool it to room temperature, then put the pre-treated sample into the sample cup. The sample should not be less than two-thirds of the height of the sample cup. Cover the sample cover, press the test button, and test the L, a, and b values. Test three times and take the arithmetic average of the three times for the same sample. Melt index: Chengde Jinjian MFI-1221 melt flow rate instrument is used. Test method: weigh 6g sample slices, add them into the die through the hopper, preheat at the set temperature for 4 minutes and then start the test. The load is 2.16kg. The test temperature is 190℃; End carboxyl group: Weigh 0.1000±0.0001g of sample, put it into a 150ml conical flask, use a 25mL pipette to transfer 25mL of solution, immerse the conical flask 1cm to 2cm below the surface of the 203±3℃ salt bath, and heat for 2 minutes and 30 seconds. Shake it gently to dissolve it completely, take it out and place it in a sink to cool to room temperature, take out the conical flask, and use a 5mL pipette to add 5mL of chloroform to the sample bottle, add 5 drops of 0.0002gmL phenolphthalein indicator, and titrate with 0.02mol / L potassium hydroxide-benzyl alcohol solution. The end point is when the solution color changes from yellow to light pink. Test a blank and two parallel samples in the same way; Mechanical properties are measured according to ISO 527 "Determination of tensile properties of plastics"; Hardness is measured according to ISO 868 "Plastics and hard rubber - Determination of indentation hardness by durometer".

[0040] The results are shown in Table 1. It can be seen from Table 1 that, compared with Comparative Example 1, the PBAT copolymer resin composition obtained by adjusting the amount of component D added and mixing in the proportions described in the above embodiment has low hardness, high toughness, and good processing fluidity.

[0041] In summary, in the present invention, by adding some auxiliary agents to inhibit side reactions, the preparation method can effectively reduce the hardness of PBAT resin, improve the toughness of PBAT resin, and obtain a PBAT copolymer resin composition with low strength and high toughness. The hardness of the obtained PBAT copolymer resin composition can reach as low as 78.5A, and it has fast cooling and molding, and is easy to demold, which is qualitatively different from conventional PBAT, reduces the cost of rear-end modified products, breaks the limitations of existing PBAT resin applications, and can be widely used in the field of flexible resins.

[0042] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A PBAT copolymer resin composition, characterized in that The raw materials include, by mole percentage, 20% to 33% of component A, 20% to 33% of component B, 44% to 59% of component C, 0.2% to 5% of component D and a required amount of additives, wherein component A is terephthalic acid or terephthalic acid glycol ester, component B is adipic acid, component C is 1,4-butanediol, and component D is one or more of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone and polycaprolactone diol.

2. The PBAT copolymer resin composition according to claim 1, characterized in that The auxiliary agents include catalysts, antioxidants, stabilizers, and cross-linking agents, wherein the catalyst is one or more of a titanium catalyst, a germanium catalyst, an aluminum catalyst, and a magnesium catalyst; the antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 1098, antioxidant 445, antioxidant 1425, and antioxidant 1222; the stabilizer is one or more of triphenyl phosphate, disodium hydrogen phosphate, tricalcium phosphate, trisodium phosphate, and triethyl phosphate; and the cross-linking agent is one or more of tartaric acid, malic acid, citric acid, glycerol, pentaerythritol, and polyether triol.

3. The PBAT copolymer resin composition according to claim 1 or 2, characterized in that Prepared according to the following steps: The first step is to uniformly mix the required amounts of component A, component B, and component C under a high-purity nitrogen atmosphere to obtain a mixed slurry; The second step is to heat the mixed slurry to carry out esterification reaction to obtain an esterification product; The third step is to add the required amount of component D to the esterification product, mix them evenly, and obtain a mixed melt; The fourth step is to subject the mixed melt to an esterification reaction again to obtain a prepolymer; The fifth step is to add a required amount of additives to the prepolymer to carry out polycondensation reaction to obtain a fluid PBAT copolymer resin composition; The sixth step is to subject the fluid PBAT copolymer resin composition to water cooling, solidification, pelletizing, and drying to obtain a PBAT copolymer resin composition.

4. The PBAT copolymer resin composition according to claim 3, characterized in that In the second step, the reaction temperature is raised to 150°C to 200°C, held for 10 minutes to 30 minutes, and then continued to rise to 220°C to 240°C.

5. The PBAT copolymer resin composition according to claim 3 or 4, characterized in that In the fourth step, the reaction temperature is 220° C. to 260° C., and the residence time is 5 minutes to 15 minutes.

6. The PBAT copolymer resin composition according to claim 3, 4 or 5, characterized in that In the fifth step, the reaction pressure is 10 Pa to 200 Pa, the reaction temperature is 230° C. to 260° C., and at the end of the reaction, the melt index is specified to be 3 g / 10 min to 10 g / 10 min.

7. A method for preparing the PBAT copolymer resin composition according to any one of claims 1 to 6, characterized in that The following steps are involved: The first step is to uniformly mix the required amounts of component A, component B, and component C under a high-purity nitrogen atmosphere to obtain a mixed slurry; The second step is to heat the mixed slurry to carry out esterification reaction to obtain an esterification product; The third step is to add the required amount of component D to the esterification product, mix them evenly, and obtain a mixed melt; The fourth step is to subject the mixed melt to an esterification reaction again to obtain a prepolymer; The fifth step is to add a required amount of additives to the prepolymer to carry out polycondensation reaction to obtain a fluid PBAT copolymer resin composition; The sixth step is to subject the fluid PBAT copolymer resin composition to water cooling, solidification, pelletizing, and drying to obtain a PBAT copolymer resin composition.

8. The method for preparing the PBAT copolymer resin composition according to claim 7, characterized in that In the second step, the reaction temperature is raised to 150°C to 200°C, held for 10 minutes to 30 minutes, and then continued to rise to 220°C to 240°C.

9. The method for preparing the PBAT copolymer resin composition according to claim 7 or 8, characterized in that In the fourth step, the reaction temperature is 220° C. to 260° C., and the residence time is 5 minutes to 15 minutes.

10. The method for preparing the PBAT copolymer resin composition according to claim 7, 8 or 9, characterized in that In the fifth step, the reaction pressure is 10 Pa to 200 Pa, the reaction temperature is 230° C. to 260° C., and at the end of the reaction, the melt index is specified to be 3 g / 10 min to 10 g / 10 min.

Images