CN118063943A

CN118063943A - High-toughness biodegradable polylactic acid composite material and preparation method thereof

Info

Publication number: CN118063943A
Application number: CN202311487583.0A
Authority: CN
Inventors: 姜伟; 鲍伟; 金晶; 高云宝; 张佳宁
Original assignee: Changchun Institute of Applied Chemistry of CAS
Current assignee: Changchun Institute of Applied Chemistry of CAS
Priority date: 2023-11-09
Filing date: 2023-11-09
Publication date: 2024-05-24

Abstract

The invention discloses a high-toughness biodegradable polylactic acid composite material and a preparation method thereof, and belongs to the technical field of biodegradable materials. Aiming at the characteristic of poor toughness of polylactic acid, the biodegradable high-performance polylactic acid composite material is prepared by blending biodegradable polyether amide copolymer (Pebax), polybutylene succinate (PBS) and PLA, and the composite material forms a core-shell structure with PBS as a core and Pebax as a shell. In addition, the notch impact strength of the polylactic acid composite material prepared by the synthetic method is greatly improved, the maximum is 53.59KJ/m ², which is 18 times that of pure polylactic acid, and the preparation process is simple and easy to operate.

Description

High-toughness biodegradable polylactic acid composite material and preparation method thereof

Technical Field

The invention belongs to the technical field of biodegradable materials, and particularly relates to a high-toughness biodegradable polylactic acid composite material and a preparation method thereof.

Background

Among the degradable biopolymers that have been commercialized at present, polylactic acid (PLA) is considered as one of the most promising applications, and has received extensive attention in academia and industry in recent years. PLA can be obtained from renewable resources such as sugarcane or straw, and the discarded polylactic acid can be completely decomposed into water and carbon dioxide by microorganisms in nature. Meanwhile, the polylactic acid has the advantages of high strength, good transparency, good biocompatibility and the like. Secondly, polylactic acid has good processability, and can be molded by adopting general processing methods such as extrusion, injection molding, blow molding, spinning and the like. Polylactic acid, however, has poor flexibility and impact resistance, which greatly limits its range of applications.

At present, the PLA toughening modification is divided into chemical modification and physical modification, wherein the chemical modification method is to copolymerize lactic acid or PLA oligomer with other polymers or react PLA with substances containing active functional groups, so as to improve the toughness of the PLA. The chemical modification method is relatively complex and its application in industrial scale-up is limited. The physical modification is to physically blend PLA with other polymeric materials to achieve toughened PLA. PLA is typically blended with materials such as elastomers, inorganic fillers, or plasticizers to improve the toughness of the PLA. The physical modification method is simple and convenient, and becomes the most common modification mode in the current industrial production.

Polyether amide copolymer (Pebax) is polyether amide thermoplastic elastomer, its hard segment is PA11, it is derived from the regenerated resource castor oil, the soft segment is polyether, pebax also has good biocompatibility. PLA/Pebax blending can change the processability and brittleness of PLA and expand the application of PLA in the field of general plastics. Secondly, PLA and Pebax are both derived from renewable resources, which is beneficial to meeting the current demand of sustainable development. Meanwhile, the PLA/Pebax blending system has good biocompatibility and can be widely applied to the biomedical field. However, pebax has poor compatibility with PLA, which limits to some extent the use of PLA/Pebax blends.

Polybutylene succinate (PBS) is an aliphatic thermoplastic polyester, is one of bioplastic with excellent comprehensive performance, and is a green and renewable environment-friendly plastic, wherein the main raw material of the polybutylene succinate (PBS) is from the nature. Due to their biodegradability, processability, heat and chemical resistance and similar mechanical properties to PP and PE, have been gradually considered as a biodegradable polymer promising alternatives to petrochemicals.

CN116535836a provides a full-biodegradable polylactic acid composite material and a preparation method thereof. This patent forms blend a and blend b by melt blending a copolymer of butylene adipate and butylene terephthalate (PBAT-g-GMA) with thermoplastic starch (TPS) and polylactic acid (PLA), respectively, in proportions to Glycidyl Methacrylate (GMA). And finally, carrying out melt blending on the blend a and the blend b again according to the proportion to obtain the high-toughness environment-friendly PLA/PBAT-g-GMA/TPS composite material taking TPS as a core and PBAT as a shell. Compared with the patent, the preparation process is simple, and the plasticizing process and the mixing process of the starch are reduced.

CN106916423a provides a high-toughness polylactic acid composite material and a preparation method thereof. The patent uses the grafted and modified elastomer to toughen the polylactic acid to improve the impact resistance of the composite material by carrying out grafting modification on the elastomer POE, SEBS, ABS. Compared with the elastomer POE, SEBS, ABS in the patent, the Pebax and PBS used in the invention are biodegradable polymers, and the fully biodegradable polylactic acid composite material is prepared.

CN103788605A provides a polylactic acid composite material and a preparation method thereof. The patent uses a component A (polyether amide copolymer grafted with glycidyl methacrylate (Pebax-g-GMA) and a component PLA) B (thermoplastic starch acetate (TPAS) and polylactic acid grafted with maleic anhydride (PLA-g-MA)) to prepare the high-impact and low-cost full-biodegradable polylactic acid composite material according to different proportions. Compared with the patent, the invention uses the synergistic effect of Pebax and PBS to toughen PLA, has simple preparation process and reduces the starch plasticizing process, grafting process and mixing process.

Polylactic acid (PLA) is a biodegradable polymer material with high strength, but its application is limited due to its inherent brittleness, poor toughness, etc., and needs to be improved by various modification methods. Most of the traditional modification methods can only improve the toughness single performance of PLA, and the mechanical performance and the degradation performance of PLA can be rarely considered.

Disclosure of Invention

This section is intended to outline some aspects of embodiments of the application and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description of the application and in the title of the application, which may not be used to limit the scope of the application.

The present invention has been made in view of the above and/or problems occurring in the prior art.

Therefore, the invention aims to overcome the defects in the prior art and provide a high-toughness biodegradable polylactic acid composite material, which comprises the following components in percentage by mass,

80 To 60 percent of polylactic acid, 10 to 20 percent of polyether amide copolymer or polyether amide copolymer grafted with glycidyl methacrylate, and 10 to 20 percent of polybutylene succinate.

The invention also aims to overcome the defects in the prior art and provide a preparation method of the high-toughness biodegradable polylactic acid composite material.

In order to solve the technical problems, the invention provides the following technical proposal, which comprises that,

And (3) drying and then melt blending the polylactic acid, polyether amide copolymer or polyether amide copolymer grafted with glycidyl methacrylate and polybutylene succinate to obtain the high-toughness biodegradable polylactic acid composite material.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the mass ratio of the polylactic acid to the polyether amide copolymer to the polybutylene succinate is 8-6:1-2:1-2.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the preparation method of the polyether amide copolymer grafted with glycidyl methacrylate comprises the following steps of,

And (3) drying and premixing the polyether amide copolymer, and then rapidly and simultaneously adding glycidyl methacrylate, 1-vinyl-2-pyrrolidone and dicumyl peroxide to carry out a grafting reaction to obtain the polyether amide copolymer grafted with the glycidyl methacrylate.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the drying temperature is 40-60 ℃.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the drying time is 8-12 h.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the temperature of the pre-mixing grafting reaction is 160-200 ℃.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the grafting reaction time is 2-5 min.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the mass ratio of the polyether amide copolymer to the glycidyl methacrylate to the 1-vinyl-2-pyrrolidone to the dicumyl peroxide is 100:3-5:3-5:0.3-0.5.

As a preferable scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method comprises the following steps: the blending temperature of the melt blending is 160-200 ℃, the rotating speed is 60-80 rpm, and the blending time is 4-6 min.

The invention has the beneficial effects that:

Aiming at the characteristic of poor toughness of polylactic acid, the biodegradable high-performance polylactic acid composite material is prepared by blending biodegradable polyether amide copolymer (Pebax), polybutylene succinate (PBS) and PLA, and the composite material forms a core-shell structure with PBS as a core and Pebax as a shell. Impact tests show that the notch impact strength of the prepared polylactic acid composite material is greatly improved, the maximum is 53.59KJ/m ², which is 18 times that of pure polylactic acid, and the prepared polylactic acid composite material has high toughness. Meanwhile, the polyether amide copolymer (Pebax-g-GMA) grafted with glycidyl methacrylate is utilized to further improve the interfacial compatibility of PLA/Pebax, so that the formation of a core-shell structure is facilitated, and the toughness of the polylactic acid composite material is effectively improved. The preparation method is simple and easy to operate, and the high-performance biodegradable polylactic acid composite material is successfully prepared in a simple blending mode.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:

FIG. 1 is a SEM image of a brittle fracture of the polylactic acid composite material prepared in example 1 of the present invention.

FIG. 2 is an SEM image of the polylactic acid composite material prepared in example 1 of the present invention after the liquid nitrogen brittle fracture surface is etched for 12 hours at 80 ℃ by n-butanol to remove Pebax.

FIG. 3 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in example 2.

Fig. 4 is an SEM image of the polylactic acid composite material prepared in example 2 after the Pebax is removed by etching with n-butanol at 80 ℃ for 12 hours.

FIG. 5 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in example 3.

FIG. 6 is an SEM image of a liquid nitrogen brittle fracture surface of the polylactic acid composite material prepared in example 3 after being etched for 12 hours at 80 ℃ by n-butanol to remove Pebax-g-GMA.

FIG. 7 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in example 4.

FIG. 8 is an SEM image of a liquid nitrogen brittle fracture surface of the polylactic acid composite material prepared in example 4 after being etched for 12 hours at 80 ℃ by n-butanol to remove Pebax-g-GMA.

FIG. 9 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in comparative example 1.

FIG. 10 is an SEM image of the polylactic acid composite material prepared in comparative example 1 after etching with n-butanol at 80℃for 12 hours to remove Pebax.

FIG. 11 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in comparative example 2.

FIG. 12 is an SEM image of the polylactic acid composite material prepared in comparative example 2 after etching with n-butanol at 80℃for 12 hours to remove Pebax.

FIG. 13 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in comparative example 3.

FIG. 14 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared according to comparative example 4.

FIG. 15 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in comparative example 5.

Detailed Description

In order that the above-recited objects, features and advantages of the present invention will become more apparent, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.

Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic can be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

The raw materials used in the invention are all commonly and commercially available without special description.

The material prepared by the embodiment of the invention is tested according to the following method:

according to GB/T1843-2008, the notched Izod impact strength test is carried out by using an impact tester (XJUD-5.5) manufactured by the company of Lede gold and Instrument manufacturing, the test temperature is 23+ -2 ℃.

According to GB/T1040.1-2006, a static tensile test is used for mechanical property testing by using a universal tester (Instron-1121, UK), the tensile rate is 10mm/min, and the testing temperature is 23+/-2 ℃.

The Chinese names and abbreviations of the substances used in the specific examples of the invention have the following corresponding relations:

polyether amide copolymer (Pebax)

Polylactic acid (PLA)

Polybutylene succinate (PBS)

Polyether amide copolymer grafted glycidyl methacrylate (Pebax-g-GMA)

Dicumyl peroxide (DCP)

1-Vinyl-2-pyrrolidone (NVP)

Glycidyl 2-methacrylate (GMA).

Example 1

The embodiment provides a preparation method of a high-toughness biodegradable polylactic acid composite material with Pebax as a raw material, which specifically comprises the following steps:

And (3) drying PLA, pebax and PBS in an oven at 50 ℃ for 12 hours, and then putting the mixture into an internal mixer according to the mass ratio of 8:1:1 for melt blending, wherein the melt blending temperature is 180 ℃, the rotating speed is 80rpm, and the mixture is blended for 6 minutes to obtain the polylactic acid composite material of the embodiment.

Fig. 1 is a liquid nitrogen brittle fracture SEM image of the polylactic acid composite material prepared in example 1, and it can be seen that the core-shell structure formed by PBS and Pebax is uniformly dispersed in matrix PLA in a small sphere shape, and the dispersed phase particles are smaller than 1 μm, but because of poor PLA/Pebax compatibility, there is a significant phase separation between matrix PLA and dispersed phase particles.

Fig. 2 is an SEM image of the polylactic acid composite material prepared in example 1 after the liquid nitrogen brittle fracture surface is etched by n-butanol at 80 ℃ for 12 hours to remove Pebax, a plurality of small holes appear on the polylactic acid composite material, and cores with irregular shapes exist in the holes, namely a core-shell structure taking PBS as the core and Pebax as the shell is formed, so that the high-toughness PLA/Pebax/PBS composite material with the core-shell structure is directly prepared through blending.

Example 2

The present example was different from example 1 in that the mass ratio of PLA, pebax and PBS was adjusted to 7:1.5:1.5, and the rest of the preparation process was the same as that of example 1, to obtain the polylactic acid composite material of the present example.

Fig. 3 is a liquid nitrogen brittle fracture SEM image of the polylactic acid composite material prepared in example 2, and it can be seen that the dispersed phase particles in PLA are significantly increased, and similarly, there is a significant phase separation between matrix PLA and the dispersed phase particles.

Fig. 4 is an SEM image of the polylactic acid composite material prepared in example 2 after the Pebax is removed by etching n-butanol at 80 ℃ for 12 hours, a plurality of small holes are formed, and irregularly shaped cores are present in the holes, but the holes are larger than those in example 1 and are unevenly distributed, and the dispersed phase is changed to the continuous phase, so that toughening of PLA cannot be realized.

The composite materials prepared in the above examples were subjected to performance test, and the results of comparison with example 1 are shown in table 1.

TABLE 1

As can be seen from examples 1 and 2, the toughness of PLA can be obviously enhanced by adding Pebax and PBS into PLA according to a proportion, a high-toughness polylactic acid composite material is prepared, the impact strength of the composite material is up to 44.52KJ/m ², which is 15 times that of pure PLA, and meanwhile, when the ratio of PLA, pebax and PBS is 8:1:1, the best technical effect is obtained, at the moment, the tensile modulus is 1245.2MPa, the elongation at break can reach 35.3%, and both high toughness and mechanical property are considered; the impact strength of the composite material was 10.60KJ/m ² at a ratio of PLA, pebax and PBS of 7:1.5:1.5, 3 times that of pure PLA. This is because PLA/Pebax interface compatibility is poor, too high a content of Pebax and PBS is unfavorable for preparing high toughness polylactic acid composite material.

Example 3

The embodiment provides a preparation method of a high-toughness biodegradable polylactic acid composite material with Pebax-g-GMA as a raw material, which specifically comprises the following steps:

1) The Pebax is dried for 12 hours in advance at 50 ℃, and is added into an internal mixer cavity at 180 ℃ for premixing for 2 minutes, then DCP, GMA, NVP is added quickly and simultaneously, and the first blending is continued for 5 minutes to carry out grafting reaction. The mass ratio of Pebax to GMA to NVP to DCP=100:3:3:0.3, polyether amide copolymer of grafted glycidyl methacrylate (Pebax-g-GMA) is obtained;

2) PLA, pebax-g-GMA and PBS are put into an internal mixer according to the mass ratio of 8:1:1, and are mixed for 6min at the temperature of 180 ℃ and the rotating speed of 80rpm, so as to obtain the polylactic acid composite material of the embodiment.

FIG. 5 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in example 3, and it can be found that the dispersed phase particles are uniformly distributed in the PLA matrix in the form of pellets, and the size of the dispersed phase particles is less than 1 μm.

FIG. 6 is an SEM image of a polylactic acid composite material prepared in example 3 after a liquid nitrogen brittle fracture surface is etched by n-butanol at 80 ℃ for 12 hours to remove Pebax-g-GMA, and it can be seen that a plurality of small holes appear after the Pebax-g-GMA is etched, and cores with irregular shapes exist in the holes, namely a core-shell structure taking PBS as a core and Pebax-g-GMA as a shell is formed. Compared with example 1, the core-shell structure is obviously more abundant, namely, the Pebax-g-GMA grafted with the GMA is more beneficial to forming the core-shell structure, the toughness of the composite material is improved, and meanwhile, the notch impact strength shows that example 3 is improved by 20% compared with example 1.

Example 4

The difference between this example and example 3 is that the mass ratio of PLA, pebax-g-GMA and PBS is adjusted to 7:1.5:1.5, and the rest of the preparation process is the same as that of example 3, so as to obtain the polylactic acid composite material.

Fig. 7 is a liquid nitrogen brittle fracture SEM image of the polylactic acid composite material prepared in example 4, and it can be seen that the particle size of the dispersed phase particles is larger than that of example 3.

FIG. 8 is an SEM image of a polylactic acid composite material prepared in example 4 after a liquid nitrogen brittle fracture surface is etched by n-butanol at 80 ℃ for 12 hours to remove Pebax-g-GMA, and it can be seen that a plurality of small holes appear after the Pebax-g-GMA is etched, and cores with irregular shapes exist in the holes, namely a core-shell structure taking PBS as a core and Pebax-g-GMA as a shell is formed. The toughening effect was slightly worse than in example 3 because of the larger particle size of the dispersed phase. However, compared with example 2 in the same proportion, the core-shell structure is obviously more, the particle size of the disperse phase is smaller, so that Pebax-g-GMA grafted with GMA is more beneficial to forming the core-shell structure, and the data show that the notch impact strength of example 4 is improved by 263% compared with that of example 2.

The composite materials prepared in the above examples were subjected to performance test, and the results of comparison with example 1 are shown in table 2.

TABLE 2

Examples 3-4 show that when PLA, pebax-g-GMA, and PBS are used to blend, the notched impact strength of the polylactic acid composite is improved by 20% and 263% respectively, compared to examples 1-2, and the modified polyether amide copolymer introduces more crosslinking points and branching structures, increasing the affinity and coexistence of the materials. This means that Pebax-g-GMA is better dispersed in PLA and PBS matrix, forming a more uniform composite structure. A more uniform dispersion may increase the interfacial bond strength and interpenetrating network of the material, thereby improving toughness and strength.

Example 5

The present example was different from example 1 in that the blending temperature was adjusted to 160℃and the rest of the preparation process was the same as in example to obtain a polylactic acid composite material.

Example 6

The present example was different from example 1 in that the blending temperature was adjusted to 200℃and the rest of the preparation process was the same as in example to obtain a polylactic acid composite material.

The composite materials prepared in the above examples were subjected to performance test, and the results of comparison with example 1 are shown in table 3.

TABLE 3 Table 3

Examples 5 to 6 show that varying the blending temperature has a significant effect on the toughness of the material, and that the choice of blending temperature can affect the crystallization behavior of the polylactic acid composite. Suitable blending temperatures may promote crystallization of Pebax-g-GMA and PBS and form fine and uniformly distributed crystals in the PLA matrix. This can increase the strength of the material and improve the mechanical properties. In addition, the blending temperature may also affect the morphology and crystal size of the crystals, further affecting the toughness of the material.

Comparative example 1

The difference between this example and example 1 is that the mass ratio of PLA and Pebax is adjusted to 8:2, and the rest of the preparation process is the same as that of example 1, so as to obtain the polylactic acid composite material.

Fig. 9 is a liquid nitrogen brittle fracture SEM image of the polylactic acid composite material prepared in comparative example 1, and fig. 10 is a SEM image after Pebax is removed, and it can be found that Pebax is uniformly dispersed in a matrix PLA in a small sphere shape, and the particle size is less than 1 μm, but because PLA/Pebax has large interfacial strength tension and poor compatibility, obvious phase separation exists, and a certain toughening effect is achieved.

Comparative example 2

The difference between this example and example 1 is that the mass ratio of PLA and Pebax is adjusted to 7:3, and the rest of the preparation process is the same as that of example 1, so as to obtain the polylactic acid composite material.

FIG. 11 is a SEM image of a brittle fracture of liquid nitrogen of the polylactic acid composite material prepared in comparative example 2, and FIG. 12 is a SEM image after removing Pebax, wherein it can be found that Pebax is uniformly dispersed in a matrix PLA in a small sphere shape, but the size of dispersed phase particles is obviously increased with the increase of the proportion, and an agglomeration phenomenon exists; and the particle size in the graph is obviously larger than 1 mu m, and the agglomeration phenomenon of the disperse phase is obvious, so that the toughening of PLA can not be realized.

Comparative example 3

The difference between this example and example 1 is that the mass ratio of PLA and PBS is adjusted to 8:2, and the rest of the preparation process is the same as that of example 1, so as to obtain the polylactic acid composite material.

FIG. 13 is a SEM image of a liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in comparative example 3, which shows that PLA/PBS has poor compatibility, and thus PLA cannot be toughened alone.

Comparative example 4

The difference between this example and example 3 is that the mass ratio of PLA and Pebax-g-GMA is adjusted to 8:2, and the rest of the preparation process is the same as that of example 3, so as to obtain the polylactic acid composite material.

FIG. 14 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in comparative example 3.

Comparative example 5

The difference between this example and example 3 is that the mass ratio of PLA and Pebax-g-GMA is adjusted to 7:3, and the rest of the preparation process is the same as that of example 3, so as to obtain the polylactic acid composite material.

FIG. 15 is a SEM image of a liquid nitrogen brittle fracture of the polylactic acid composite material prepared in comparative example 3.

It can be seen that the Pebax-g-GMA grafted with GMA improves the compatibility of PLA/Pebax because the GMA group on Pebax-g-GMA reacts with the terminal group (-OH, -COOH) of PLA during melt blending to form a graft copolymer between the two phases, and the copolymer can effectively reduce the interfacial tension between the two phases, improve the interfacial compatibility, and prevent agglomeration of the dispersed phases. Compared with the polylactic acid composite material prepared by ungrafted Pebax, the surface of the polylactic acid composite material is smoother, and no obvious phase separation exists. However, when the ratio of PLA/Pebax-g-GMA is 7:3, the content is too high, the dispersion is difficult to uniformly disperse, the dispersed phase tends to be changed into the continuous phase, and even if the interface compatibility is improved, the toughening is difficult.

The composite materials prepared in the above comparative examples were subjected to performance test, and the results of comparison with examples 1 and 3 are shown in table 4.

TABLE 4 Table 4

The comparative examples show that blending Pebax alone with PLA, PBS alone with PLA, or Pebax-g-GMA with PLA, none can produce polylactic acid composites that compromise both high toughness and mechanical properties.

In conclusion, the invention discloses a high-toughness biodegradable polylactic acid composite material and a preparation method thereof, and belongs to the technical field of biodegradable materials. Aiming at the characteristic of poor toughness of polylactic acid, the biodegradable high-performance polylactic acid composite material is prepared by blending biodegradable polyether amide copolymer (Pebax), polybutylene succinate (PBS) and PLA, and the composite material forms a core-shell structure with PBS as a core and Pebax as a shell. In addition, the notch impact strength of the polylactic acid composite material prepared by the synthetic method is greatly improved, the maximum is 53.59KJ/m ², which is 18 times that of pure polylactic acid, and the preparation process is simple and easy to operate.

It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered in the scope of the claims of the present invention.

Claims

1. A high-toughness biodegradable polylactic acid composite material is characterized in that: the composite material comprises, in mass percent,

2. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 1, which is characterized in that: comprising the steps of (a) a step of,

3. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 2, which is characterized in that: the mass ratio of the polylactic acid to the polyether amide copolymer or the polyether amide copolymer grafted with the glycidyl methacrylate to the polybutylene succinate is 8-6:1-2:1-2.

4. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 2, which is characterized in that: the blending temperature of the melt blending is 160-200 ℃, the rotating speed is 60-80 rpm, and the blending time is 4-6 min.

5. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 2, which is characterized in that: the preparation method of the polyether amide copolymer grafted with glycidyl methacrylate comprises the following steps of,

And (3) drying and premixing the polyether amide copolymer, and simultaneously adding glycidyl methacrylate, 1-vinyl-2-pyrrolidone and dicumyl peroxide for grafting reaction to obtain the polyether amide copolymer grafted with the glycidyl methacrylate.

6. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 5, which is characterized in that: the drying temperature is 40-60 ℃.

7. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 5, which is characterized in that: the drying time is 8-12 h.

8. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 5, which is characterized in that: the temperature of the pre-mixing grafting reaction is 160-200 ℃.

9. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 5, which is characterized in that: the grafting reaction time is 2-5 min.

10. The method for preparing the high-toughness biodegradable polylactic acid composite material according to claim 5, which is characterized in that: the mass ratio of the polyether amide copolymer to the glycidyl methacrylate to the 1-vinyl-2-pyrrolidone to the dicumyl peroxide is 100:3-5:3-5:0.3-0.5.