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

Abstract

The application 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 poor toughness of polylactic acid, the application prepares a biodegradable high-performance polylactic acid composite material by blending biodegradable polyether amide copolymer (Pebax) and polybutylene succinate (PBS) with PLA; the composite material forms a core-shell structure with PBS as the core and Pebax as the shell.In addition, the notched impact strength of the polylactic acid composite material prepared by the synthesis method is greatly improved, and the highest notched impact strength is 53.59 KJ / m 2 , which is 18 times that of pure polylactic acid, and the preparation process is simple and easy to operate.

Description

TECHNICAL FIELD

[0001] The application 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

[0002] Among the currently commercialized biodegradable polymers, polylactic acid (PLA) is considered to be the most promising one and has attracted extensive attention from the academic and industrial circles in recent years. PLA can be obtained from renewable resources such as sugar cane or straw, and after being discarded, it can be completely decomposed into water and carbon dioxide by microorganisms in nature. In addition, PLA has many advantages such as high strength, good transparency and good biocompatibility. Furthermore, PLA also has good processing performance and can be molded by common processing methods such as extrusion, injection molding, blow molding and spinning. However, the flexibility and impact resistance of PLA are poor, which to a large extent limits its application range.

[0003] At present, the toughening modification of PLA is divided into chemical modification and physical modification. The chemical modification method is to copolymerize lactic acid or PLA oligomer with other polymers, or to react PLA with substances containing active functional groups, so as to improve the toughness of PLA. The chemical modification method is relatively complex, and its application is limited in industrialization. The physical modification method is to physically blend PLA with other polymer materials, so as to toughen PLA. Usually, PLA is blended with elastomers, inorganic fillers or plasticizers and other materials to improve the toughness of PLA. The physical modification method is simple and convenient, and has become the most commonly used modification method in current industrial production.

[0004] Polyether amide copolymer (Pebax) is a polyether amide thermoplastic elastomer, and its hard segment is PA11, which is derived from renewable resources such as castor oil. The soft segment is a polyether, and Pebax also has good biocompatibility. The blending of PLA and Pebax can change the processability and brittleness of PLA and expand the application of PLA in the field of general plastics. In addition, both PLA and Pebax are derived from renewable resources, which is conducive to meeting the current demand for sustainable development. At the same time, the PLA / Pebax blending system has good biocompatibility and can be widely used in the field of biomedical materials. However, the compatibility of Pebax and PLA is poor, which to some extent limits the application of the PLA / Pebax blending system.

[0005] Polybutylene succinate (PBS) is an aliphatic thermoplastic polyester, which is one of the bioplastics with excellent comprehensive performance. Its main raw material comes from nature and is a green and renewable environment-friendly plastic. Due to its biodegradability, processability, heat resistance and chemical resistance as well as similar mechanical properties to PP and PE, it has gradually been considered as a biodegradable polymer that can replace petrochemical products.

[0006] CN116535836A provides a kind of full biodegradable polylactic acid composite material and its preparation method.The patent is by grafting glycidyl methacrylate (GMA) hexanedioate and terephthalate butylene glycol ester copolymer (PBAT-g-GMA) with thermoplastic starch (TPS) and polylactic acid (PLA) respectively according to proportion melt blending, form blend a and blend b.Finally, blend a and blend b are according to the proportion again melt blending, obtain the high toughness, environmental protection PLA / PBAT-g-GMA / TPS composite material with TPS as core, with PBAT as shell.Compared with the patent, the preparation process is simple, and the plasticizing process and mixing process of starch are reduced.

[0007] CN106916423A provides a kind of high toughness polylactic acid composite material and its preparation method.The patent is by grafting modification to elastomer POE, SEBS, ABS, using the elastomer toughened polylactic acid after grafting modification to improve the impact resistance of composite material.Compared with the elastomer POE, SEBS, ABS in the patent, the Pebax and PBS used in the application are biodegradable polymers, and the preparation is a full biodegradable polylactic acid composite material.

[0008] CN103788605A provides a kind of polylactic acid composite material and its preparation method.The patent uses A component (grafting glycidyl methacrylate polyether amide copolymer (Pebax-g-GMA) and PLA) B component (thermoplastic starch acetate (TPAS) and grafting maleic anhydride polylactic acid (PLA-g-MA)) is mixed according to different proportions to prepare high impact, low cost full biodegradable polylactic acid composite material.Compared with the patent, the Pebax and PBS used in the application synergistically toughen PLA, the preparation process is simple, and the plasticizing process, grafting process and mixing process of starch are reduced.

[0009] Polylactic acid (PLA) is a kind of biodegradable high molecular material with high strength, but due to its inherent brittleness, poor toughness and other shortcomings, it needs to be improved by various modification methods.The traditional modification method can only improve the single performance of PLA toughness, and rarely can consider the mechanical properties and degradation performance of PLA. SUMMARY

[0010] This section aims to summarize some aspects of the embodiments of the application and briefly introduce some preferred embodiments.Some simplifications or omissions may be made in this section, as well as the abstract and title of the specification, to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the application.

[0011] In view of the above and / or problems existing in the prior art, the present application is proposed.

[0012] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art, and provide a high-toughness biodegradable polylactic acid composite material, which comprises, in mass percentage,

[0013] 80% to 60% of polylactic acid, 10% to 20% of polyether amide copolymer or grafted glycidyl methacrylate polyether amide copolymer, and 10% to 20% of polybutylene succinate.

[0014] Another purpose of the present application is to overcome the deficiencies in the prior art, and provide a preparation method of the high-toughness biodegradable polylactic acid composite material.

[0015] To solve the above technical problems, the present application provides the following technical solutions, which comprise,

[0016] The polylactic acid, the polyether amide copolymer or the grafted glycidyl methacrylate polyether amide copolymer, and the polybutylene succinate are dried and then melt blended, so as to obtain the high-toughness biodegradable polylactic acid composite material.

[0017] As a preferred solution of the preparation method of the high-toughness biodegradable polylactic acid composite material, the mass ratio of the polylactic acid, the polyether amide copolymer, and the polybutylene succinate is 8 to 6:1 to 2:1 to 2.

[0018] As a preferred solution of the preparation method of the high-toughness biodegradable polylactic acid composite material, the preparation method of the grafted glycidyl methacrylate polyether amide copolymer comprises,

[0019] The polyether amide copolymer is premixed after drying, and then the glycidyl methacrylate, 1-vinyl-2-pyrrolidone, and dicumyl peroxide are quickly added at the same time to perform grafting reaction, so as to obtain the grafted glycidyl methacrylate polyether amide copolymer.

[0020] As a preferred solution of the preparation method of the high-toughness biodegradable polylactic acid composite material, the drying temperature is 40 to 60°C.

[0021] As a preferred solution of the preparation method of the high-toughness biodegradable polylactic acid composite material, the drying time is 8 to 12 hours.

[0022] As a preferred solution of the preparation method of the high-toughness biodegradable polylactic acid composite material, the premixing and grafting reaction temperature is 160 to 200°C.

[0023] As a preferred scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the grafting reaction time is 2-5 min.

[0024] As a preferred scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the mass ratio of the polyether amide copolymer, glycidyl methacrylate, 1-vinyl-2-pyrrolidone and dicumyl peroxide is 100:3-5:3-5:0.3-0.5.

[0025] As a preferred scheme of the preparation method of the high-toughness biodegradable polylactic acid composite material, the blending temperature of the melt blending is 160-200 DEG C, the rotation speed is 60-80 rpm, and the blending time is 4-6 min.

[0026] The present application has the following beneficial effects:

[0027] In view of the poor toughness of polylactic acid, a biodegradable high-performance polylactic acid composite material is prepared by blending biodegradable polyether amide copolymer (Pebax) and polybutylene succinate (PBS) with PLA, and the composite material forms a core-shell structure with PBS as the core and Pebax as the shell. Impact test shows that the notched impact strength of the prepared polylactic acid composite material is greatly improved, and the highest is 53.59 KJ / m 2 , which is 18 times that of pure polylactic acid, and the prepared polylactic acid composite material has high toughness. At the same time, the polyether amide copolymer (Pebax-g-GMA) grafted with glycidyl methacrylate is used to further improve the interfacial compatibility of PLA / Pebax, which is more conducive to the formation of the core-shell structure and effectively improves the toughness of the polylactic acid composite material. The preparation method of the present application is simple and easy to operate, and a high-performance biodegradable polylactic acid composite material is successfully prepared by simple blending. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0029] Figure 1 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in Example 1 of the present application.

[0030] Figure 2 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in Example 1 of the present application after etching the Pebax with n-butanol at 80 DEG C for 12 h.

[0031] Figure 3 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Example 2.

[0032] Figure 4 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Example 2 after removal of Pebax-g-GMA by n-butanol etching at 80°C for 12h.

[0033] Figure 5 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Example 3.

[0034] Figure 6 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Example 3 after removal of Pebax-g-GMA by n-butanol etching at 80°C for 12h.

[0035] Figure 7 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Example 4.

[0036] Figure 8 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Example 4 after removal of Pebax-g-GMA by n-butanol etching at 80°C for 12h.

[0037] Figure 9 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Comparative Example 1.

[0038] Figure 10 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Comparative Example 1 after removal of Pebax by n-butanol etching at 80°C for 12h.

[0039] Figure 11 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Comparative Example 2.

[0040] Figure 12 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Comparative Example 2 after removal of Pebax by n-butanol etching at 80°C for 12h.

[0041] Figure 13 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Comparative Example 3.

[0042] Figure 14 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Comparative Example 4.

[0043] Figure 15 SEM image of liquid nitrogen brittle fracture section of polylactic acid composite prepared in Comparative Example 5. DETAILED DESCRIPTION

[0044] In order to make the above objectives, features and advantages of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the embodiments of the present application.

[0045] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may, however, be practiced in a variety of ways beyond the specific details set forth herein without departing from the scope of the present application, and it is understood that the present application is not limited to the particular details described. It is also understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present application.

[0046] Secondly, the term "one embodiment" or "an embodiment" as used herein means that a particular implementation can include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Furthermore, the following terms, as used in the description and associated claims, shall not be limited to the specifically recited terms, but are intended to cover all derivatives and synonyms, unless the context explicitly dictates otherwise.

[0047] The raw materials used in the present application are commercially available unless otherwise specified.

[0048] The material prepared in the embodiments of the present application is tested by the following method:

[0049] According to GB / T 1843-2008, the Izod impact strength test is performed by using an impact testing machine (XJUD-5.5) produced by Chengde Jinhe Instrument Manufacturing Co., Ltd., and the test temperature is 23±2℃.

[0050] According to GB / T 1040.1-2006, the mechanical property test is performed by using a static tensile test with a universal testing machine (Instron-1121, UK), the tensile rate is 10mm / min, and the test temperature is 23±2℃.

[0051] The correspondence between the Chinese name and the abbreviation of the substances used in the specific examples of the present application is as follows:

[0052] Polyether amide copolymer (Pebax)

[0053] Polylactic acid (PLA)

[0054] Polybutylene succinate (PBS)

[0055] Graft glycidyl methacrylate polyether amide copolymer (Pebax-g-GMA)

[0056] Dicumyl peroxide (DCP)

[0057] 1-Vinyl-2-pyrrolidone (NVP)

[0058] 2-methylpropylene glycol methacrylate (GMA).

[0059] Example 1

[0060] The present example provides a method for preparing a high-toughness biodegradable polylactic acid composite material using Pebax as a raw material, specifically:

[0061] After drying PLA, Pebax and PBS in an oven at 50℃ for 12h, they were put into a mixer at a mass ratio of 8:1:1, and melt blended at a temperature of 180℃ and a rotation speed of 80rpm for 6min to obtain the polylactic acid composite material of the present example.

[0062] Figure 1 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in Example 1 shows that the core-shell structure formed by PBS and Pebax is uniformly dispersed in the form of small spheres in the matrix PLA, and the dispersed phase particles are less than 1μm, but there is obvious phase separation between the matrix PLA and the dispersed phase particles due to the poor compatibility of PLA / Pebax.

[0063] Figure 2 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in Example 1 after etching with n-butanol at 80℃ for 12h to remove Pebax shows that many small holes appear on the polylactic acid composite material, and irregular cores exist in the holes, i.e. a core-shell structure with PBS as the core and Pebax as the shell is formed, thus indicating that a high-toughness PLA / Pebax / PBS composite material with a core-shell structure is directly prepared by blending.

[0064] Example 2

[0065] The difference between the present example and Example 1 is that the mass ratio of PLA, Pebax and PBS is adjusted to 7:1.5:1.5, and the rest of the preparation process is the same as that of Example 1 to obtain the polylactic acid composite material of the present example.

[0066] Figure 3 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in Example 2 shows that the dispersed phase particles in PLA are significantly increased, and similarly, there is obvious phase separation between the matrix PLA and the dispersed phase particles.

[0067] Figure 4 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in Example 2 after etching with n-butanol at 80℃ for 12h to remove Pebax also shows that many small holes appear, and irregular cores exist in the holes, but the holes are larger and more unevenly distributed than those of Example 1, and there is a trend of the dispersed phase turning into the continuous phase, thus the toughening of PLA cannot be achieved.

[0068] The performance test was carried out on the composite material prepared in the above embodiment, and the comparison results of example 1 are shown in table 1.

[0069] Table 1

[0070]

[0071]

[0072] As can be seen from examples 1 and 2, adding Pebax and PBS into PLA in proportion can significantly enhance the toughness of PLA, and high-toughness polylactic acid composite material is prepared, and the impact strength of the composite material is up to 44.52KJ / m 2 , which is 15 times of that of pure PLA. It can be seen that when the proportion of PLA, Pebax and PBS is 8:1:1, the best technical effect is obtained, at this time the tensile modulus is 1245.2MPa, and the elongation at break is up to 35.3%, which takes into account high toughness and mechanical properties; when the proportion of PLA, Pebax and PBS is 7:1.5:1.5, the impact strength of the composite material is 10.60KJ / m 2 , which is 3 times of that of pure PLA. This is because the interface compatibility of PLA / Pebax is poor, and too high content of Pebax and PBS is not conducive to the preparation of high-toughness polylactic acid composite material.

[0073] Example 3

[0074] The embodiment provides a preparation method of high-toughness biodegradable polylactic acid composite material taking Pebax-g-GMA as raw material, specifically:

[0075] 1) Pebax is dried in advance at 50℃ for 12h, and then Pebax is added into the cavity of a 180℃ internal mixer for 2min of pre-mixing, and then DCP, GMA and NVP are quickly added at the same time, and the first blending is continued for 5min for grafting reaction. The mass ratio of Pebax:GMA:NVP:DCP is 100:3:3:0.3, and a polyether amide copolymer grafted with glycidyl methacrylate (Pebax-g-GMA) is obtained;

[0076] 2) PLA, Pebax-g-GMA and PBS are put into the internal mixer in a mass ratio of 8:1:1, the melt blending temperature is 180℃, the rotating speed is 80rpm, and the blending is carried out for 6min, so that the polylactic acid composite material of the embodiment is obtained.

[0077] Figure 5 The SEM diagram of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in example 3 can be found that the dispersed phase particles are uniformly distributed in the PLA matrix in the form of small spheres, and the size of the dispersed phase particles is less than 1μm.

[0078] Figure 6 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite prepared in Example 3 after etching the Pebax-g-GMA with n-butanol at 80°C for 12h can be seen that after etching the Pebax-g-GMA, many small holes appear, and irregular-shaped cores exist in the holes, that is, a core-shell structure with PBS as the core and Pebax-g-GMA as the shell is formed. Compared with Example 1, the core-shell structure is obviously more, that is, the Pebax-g-GMA grafted with GMA is more conducive to the formation of the core-shell structure, which is conducive to the increase of the toughness of the composite, and the notched impact strength shows that the notched impact strength of Example 3 is increased by 20% compared with Example 1.

[0079] Example 4

[0080] 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, and a polylactic acid composite is obtained.

[0081] Figure 7 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite prepared in Example 4 can be seen that the particle size of the dispersed phase is larger than that of Example 3.

[0082] Figure 8 The SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite prepared in Example 4 after etching the Pebax-g-GMA with n-butanol at 80°C for 12h can be seen that after etching the Pebax-g-GMA, many small holes appear, and irregular-shaped cores exist in the holes, that is, a core-shell structure with PBS as the core and Pebax-g-GMA as the shell is formed. Because the particle size of the dispersed phase is larger, the toughening effect is slightly worse than that of Example 3. However, compared with Example 2 with the same ratio, the core-shell structure is obviously more, and the particle size of the dispersed phase is smaller, so the Pebax-g-GMA grafted with GMA is more conducive to the formation of the core-shell structure, and the data shows that the notched impact strength of Example 4 is increased by 263% compared with Example 2.

[0083] The properties of the composite prepared in the above examples were tested, and the comparison results with Example 1 are shown in Table 2.

[0084] Table 2

[0085]

[0086] Examples 3-4 show that the notched impact strength of the polylactic acid composites is increased by 20% and 263% respectively compared to Examples 1-2 when PLA, Pebax-g-GMA and PBS are blended. The modified polyetheramide copolymer introduces more crosslinking points and branched structures, increasing the affinity and compatibility of the material. This means that Pebax-g-GMA is better dispersed in the PLA and PBS matrix, forming a more uniform composite structure. More uniform dispersion can increase the interfacial bonding strength and interpenetrating network of the material, thereby improving toughness and strength.

[0087] Example 5

[0088] The difference between this example and Example 1 is that the blending temperature is adjusted to 160°C, and the rest of the preparation process is the same as Example 1, obtaining a polylactic acid composite material.

[0089] Example 6

[0090] The difference between this example and Example 1 is that the blending temperature is adjusted to 200°C, and the rest of the preparation process is the same as Example 1, obtaining a polylactic acid composite material.

[0091] The performance of the composite materials prepared in the above examples was tested, and the comparison results with Example 1 are shown in Table 3.

[0092] Table 3

[0093]

[0094] Examples 5-6 show that changing the blending temperature has a significant effect on the toughness of the material, and the choice of blending temperature can affect the crystallization behavior of the polylactic acid composite material. A suitable blending temperature can promote the 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 can also affect the morphology and size of the crystals, further affecting the toughness of the material.

[0095] Comparative Example 1

[0096] The difference between this example and Example 1 is that the mass ratio of PLA to Pebax is adjusted to 8:2, and the rest of the preparation process is the same as Example 1, obtaining a polylactic acid composite material.

[0097] Figure 9 SEM image of the liquid nitrogen brittle fracture section of the polylactic acid composite material prepared in Comparative Example 1, Figure 10The SEM image of the poly-lactic acid composite material prepared in the comparative example 2 after removing the Pebax shows that the Pebax is uniformly dispersed in the PLA matrix in the form of small particles with a size less than 1 μm. However, the interface strength between the PLA and the Pebax is large and the compatibility is poor, and thus the phase separation is obvious and the toughening effect is not good.

[0098] Comparative Example 2

[0099] The difference between this example and the example 1 is that the mass ratio of the PLA and the Pebax is adjusted to 7:3, and the other preparation processes are the same as those in the example 1, and thus the poly-lactic acid composite material is obtained.

[0100] Figure 11 The SEM image of the poly-lactic acid composite material prepared in the comparative example 2 after removing the Pebax shows that the Pebax is uniformly dispersed in the PLA matrix in the form of small particles with a size less than 1 μm. However, the interface strength between the PLA and the Pebax is large and the compatibility is poor, and thus the phase separation is obvious and the toughening effect is not good. Figure 12 The SEM image of the poly-lactic acid composite material prepared in the comparative example 2 after removing the Pebax shows that the Pebax is uniformly dispersed in the PLA matrix in the form of small particles with a size less than 1 μm. However, the interface strength between the PLA and the Pebax is large and the compatibility is poor, and thus the phase separation is obvious and the toughening effect is not good.

[0101] Comparative Example 3

[0102] The difference between this example and the example 1 is that the mass ratio of the PLA and the PBS is adjusted to 8:2, and the other preparation processes are the same as those in the example 1, and thus the poly-lactic acid composite material is obtained.

[0103] Figure 13 The SEM image of the poly-lactic acid composite material prepared in the comparative example 3 shows that the compatibility between the PLA and the PBS is poor, and thus the PLA cannot be toughened by the PBS.

[0104] Comparative Example 4

[0105] The difference between this example and the example 3 is that the mass ratio of the PLA and the Pebax-g-GMA is adjusted to 8:2, and the other preparation processes are the same as those in the example 3, and thus the poly-lactic acid composite material is obtained.

[0106] Figure 14 The SEM image of the poly-lactic acid composite material prepared in the comparative example 3.

[0107] Comparative Example 5

[0108] The difference between this example and the example 3 is that the mass ratio of the PLA and the Pebax-g-GMA is adjusted to 7:3, and the other preparation processes are the same as those in the example 3, and thus the poly-lactic acid composite material is obtained.

[0109] Figure 15 The SEM image of the poly-lactic acid composite material prepared in the comparative example 3.

[0110] It can be seen that the PLA / Pebax-g-GMA composite material has improved compatibility, which is because the GMA groups on the Pebax-g-GMA react with the end groups (-OH, -COOH) of PLA during the melt blending process, and a graft copolymer is generated between the two phases, which can effectively reduce the interfacial tension between the two phases, improve the interfacial compatibility, and prevent the aggregation of the dispersed phase. Compared with the polylactic acid composite material prepared by the ungrafted Pebax, the surface is smoother and there is no obvious phase separation. However, when the ratio of PLA / Pebax-g-GMA is 7:3, the content is too high, and it is difficult to disperse uniformly, and there is a tendency for the dispersed phase to turn into a continuous phase. Even if the interfacial compatibility is improved, it is still difficult to toughen.

[0111] The performance of the composite material prepared in the above comparative example was tested, and the comparison results with examples 1 and 3 are shown in table 4.

[0112] Table 4

[0113]

[0114]

[0115] The comparative example shows that the polylactic acid composite material with high toughness and mechanical properties cannot be prepared by blending Pebax alone with PLA, blending PBS alone with PLA, or blending Pebax-g-GMA with PLA.

[0116] In summary, the present application discloses a kind of high toughness biodegradable polylactic acid composite material and preparation method thereof, belong to biodegradable material technical field.For the characteristics of poor toughness of polylactic acid, the present application is prepared by blending biodegradable polyether amide copolymer (Pebax) and polybutylene succinate (PBS) with PLA.A kind of biodegradable high-performance polylactic acid composite material is formed, which forms a core-shell structure with PBS as the core and Pebax as the shell.In addition, the notched impact strength of the polylactic acid composite material prepared by the synthesis method is greatly improved, and the highest is 53.59KJ / m 2 , which is 18 times that of pure polylactic acid, and the preparation process is simple and easy to operate.

[0117] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A high toughness biodegradable polylactic acid composite, characterized by: The composite material comprises, in mass percentage, 80% polylactic acid, 10% polyetheramide copolymer grafted with glycidyl methacrylate, and 10% polybutylene succinate; The mass ratio of the polylactic acid, the polyetheramide copolymer grafted with glycidyl methacrylate, and the polybutylene succinate is 8:1:

1. The preparation method of the high-toughness biodegradable polylactic acid composite material comprises, The polylactic acid, the polyetheramide copolymer grafted with glycidyl methacrylate, and the polybutylene succinate are dried and then melt blended, to obtain the high-toughness biodegradable polylactic acid composite material. The blending temperature of the melt blending is 180°C, the rotation speed is 80 rpm, and the blending time is 6 min.

2. The high-ductility biodegradable polylactic acid composite of claim 1, wherein: The preparation method of the polyetheramide copolymer grafted with glycidyl methacrylate comprises, The preparation method comprises, The dried polyetheramide copolymer is premixed, glycidyl methacrylate, 1-vinyl-2-pyrrolidone, and dicumyl peroxide are added simultaneously, and a grafting reaction is performed, to obtain the polyetheramide copolymer grafted with glycidyl methacrylate.

3. The high-ductility biodegradable polylactic acid composite of claim 2, wherein: The drying temperature is 40-60°C.

4. The high-ductility biodegradable polylactic acid composite of claim 2, wherein: The drying time is 8-12 h.

5. The high toughness biodegradable polylactic acid composite of claim 2, wherein: The premixing and grafting reaction temperature is 160-200°C.

6. The high toughness biodegradable polylactic acid composite of claim 2, wherein: The grafting reaction time is 2-5 min.

7. The high ductility biodegradable polylactic acid composite of claim 2, wherein: The mass ratio of the polyetheramide copolymer, glycidyl methacrylate, 1-vinyl-2-pyrrolidone, and dicumyl peroxide is 100:3-5:3-5:0.3-0.5.

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