An anti-compression deformation modified polylactic acid foaming material and its preparation method

Abstract

The present invention discloses a compression-resistant deformed modified polylactic acid foaming material and a preparation method thereof. The modified polylactic acid material is prepared from the following raw material components by weight percentage: polylactic acid, reactive monomer, polybutylene succinate, silane coupling agent, filler. The modified polylactic acid foaming material obtained by the present invention has the characteristics of strong compression-resistant deformation ability and good resilience effect after compression, and can be widely applied to packaging cushioning materials, disposable lunch boxes, etc.

Description

Technical Field

[0001] The present invention relates to the field of modified polylactic acid materials, and particularly to a compression-resistant deformation modified polylactic acid foaming material and a preparation method thereof. Background Art

[0002] Polylactic acid (PLA) is a polyester polymer obtained by polymerizing lactic acid and is a completely biodegradable material. Polylactic acid has good thermal stability, a wide processing window of 170 - 230 °C, good solvent resistance, and can be processed in various ways such as extrusion, spinning, biaxial stretching, injection blow molding, etc., and has broad application prospects in many fields such as daily necessities, packaging, medical treatment, textiles, electronic appliances, etc. However, due to the presence of side methyl groups in the PLA molecular structure, the polylactic acid molecular chains are not easily entangled with each other, resulting in low melt strength and difficulty in foaming, which limits its application in fields such as packaging materials and lunch boxes.

[0003] Common methods to solve the problem of low melt strength of polylactic acid include introducing side groups with long molecular chains, cross-linking polylactic acid molecular chains, blending with polymers with high melt strength, etc. However, the introduced long molecular chains are often difficult to degrade or the degradation rate is affected due to the increase in molecular weight. Cross-linking of polylactic acid molecular chains will slow down the degradation rate. Currently known polymers with high melt strength are mainly non-degradable materials, and the introduction of non-degradable materials will still lead to degradation problems. In addition, although the above methods can solve the problem of low melt strength of polylactic acid, they contribute little to improving the low compression-resistant deformation ability of foamed polylactic acid. Therefore, there is currently no good solution in the industry for how to solve the relatively good compression-resistant deformation required for degradable PLA materials used in fields such as packaging materials and lunch boxes.

[0004] Patent CN102453250A solves the problem of low melt strength of polycondensable lactic acid by introducing long branched chains into the polylactic acid molecular chain. However, due to the introduction of a large number of non-degradable branched chains, the degradability of polylactic acid products will also be reduced, and the problems of low compression-resistant deformation ability and low resilience ability after compression of the products are not solved.

[0005] Patent CN107722581A prepares a polylactic acid / polyethylene alloy by melt blending to improve the crystallization and rheological behavior of the blend and enhance the viscoelasticity of the alloy. The introduction of polyethylene seriously affects the degradation of polylactic acid materials.

[0006] Patent CN109280349A obtains a polylactic acid foam material with nano-voids by melt blending. After adding a chain extender, the degree of branching increases, the number of branch points increases, the crystallization nucleation points increase, the rheological properties of the blend are improved, and the foamability of the material is enhanced. After adding fillers, the fillers can act as heterogeneous nucleation points, increasing the crystallinity and void nucleation points of the material.

[0007] The modified polylactic acid material prepared by the above patent technology fails to solve the problem of poor compression deformation resistance of the foamed polylactic acid material after foaming, and new solutions need to be found for the above problems in order to meet the application of foamed polylactic acid materials in fields such as packaging buffer materials and disposable lunch boxes. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention proposes a modified polylactic acid foaming material with high compression deformation resistance and its preparation method, effectively solving the problem that the polylactic acid material has low melt strength and cannot be foamed, and the obtained modified polylactic acid material has the characteristic of strong compression deformation resistance after foaming.

[0009] In order to achieve the above object, the technical solutions adopted by the present invention are as follows:

[0010] A modified polylactic acid foaming material with compression deformation resistance is prepared from the following raw material components by weight percentage:

[0011] Polylactic acid, 65 - 93%, preferably 75 - 88%;

[0012] Polybutylene succinate, 5 - 25%, preferably 7 - 20%;

[0013] Reaction monomer, 0.5 - 3%, preferably 1 - 2%;

[0014] Silane coupling agent, 0.5 - 3%, preferably 1 - 2%;

[0015] Filler, 1 - 10%, preferably 2 - 8%.

[0016] Further, the melt index (190 °C, 2.16 kg) of the polylactic acid (PLA) material is 3 - 30 g / 10 min, preferably 5 - 25 g / 10 min.

[0017] Further, the melt index (190 °C, 2.16 kg) of the polybutylene succinate (PBS) is 3 - 25 g / 10 min, preferably 5 - 20 g / 10 min.

[0018] Further, the silane coupling agent is a silane coupling agent containing hydroxyl and / or carboxyl reactive functional groups, preferably one or more of 3 - isocyanatopropyltriethoxysilane, 3 - isocyanatopropyltrimethoxysilane, 3 - [(2,3) - epoxypropoxy]propylmethyldimethoxysilane, 3 - (2,3 - epoxypropoxy)propyltrimethoxysilane.

[0019] Further, the reaction monomer is a monomer containing a bis-epoxy group and a biphenyl group, preferably one or more of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene, and 9,9-bis(4-epoxypropyloxyphenyl)fluorene.

[0020] Further, the filler is silica, and its particle size is preferably 5 nm to 500 nm, more preferably 10 nm to 100 nm.

[0021] The present invention also provides a method for preparing the compression-resistant deformation-modified polylactic acid foamed material as described above, comprising the following steps:

[0022] 1) Mix polybutylene succinate and a silane coupling agent uniformly in a high-speed mixer;

[0023] 2) Extrude and pelletize the mixture obtained in step 1) through a twin-screw extruder to obtain the modified PBS;

[0024] 3) Mix the modified PBS, polylactic acid, reaction monomer, and filler obtained in step 2) uniformly in a high-speed mixer;

[0025] 4) Extrude and pelletize the mixture obtained in step 3) through a twin-screw extruder to obtain the modified polylactic acid foamed material.

[0026] Further, the mixing conditions of the high-speed mixer in step 1) are: temperature is 10 to 40 °C, rotation speed is 50 to 400 rpm, preferably 100 to 300 rpm, and mixing time is 3 to 8 min, preferably 4 to 7 min.

[0027] Further, in step 2), the operating conditions of the twin-screw extruder are: screw temperature is 170 to 200 °C, preferably 175 to 190 °C, rotation speed is 150 to 500 rpm, preferably 200 to 400 rpm.

[0028] Further, the mixing conditions of the high-speed mixer in step 3) are: temperature is 10 to 40 °C, rotation speed is 50 to 400 rpm, preferably 100 to 300 rpm, and mixing time is 3 to 8 min, preferably 4 to 7 min.

[0029] Further, in step 4), the operating conditions of the twin-screw extruder are: screw temperature is 170 to 200 °C, preferably 175 to 190 °C, rotation speed is 150 to 500 rpm, preferably 200 to 400 rpm.

[0030] The present invention utilizes polybutylene succinate to form a network structure with fillers. On the one hand, it improves the melt strength of the modified polylactic acid. On the other hand, the formation of the network structure endows the prepared modified polylactic acid material with strong anti-compression deformation ability and good resilience after compression. By using a reaction monomer with double epoxy groups and a biphenyl structure, on the one hand, the molecular weight of polylactic acid is increased to enhance the melt strength. On the other hand, the introduction of the biphenyl structure enhances the strength of the foamed polylactic acid, further improving the anti-compression deformation ability of the foamed polylactic acid. In order to fully utilize the strong anti-deformation ability of the biphenyl structure and avoid introducing excessive biphenyl structure that may affect the degradation performance of the material, it is necessary to introduce the biphenyl structure into the molecular chain. The choice of double epoxy groups places the biphenyl structure in the middle of the connection between two polylactic acid molecular chains, facilitating uniform dispersion and conducive to maximizing the anti-deformation ability of the modified polylactic acid material with the least amount. In addition, the degree of crystallization of polybutylene succinate is improved under the action of filler stretching, further enhancing the anti-compression deformation ability and compression resilience of the foamed modified polylactic acid material. It is easy to foam, and after foaming, it has characteristics such as strong anti-compression deformation ability and good compression resilience effect.

[0031] Description of the drawings

[0032] Figure 1 The cell structure of the foamed modified polylactic acid. Detailed implementation manners

[0033] The present invention will be further described below through specific examples. The examples described in the present invention are only for the illustration of the present invention and do not limit the scope of the present invention.

[0034] The information of the raw materials used in the examples and comparative examples is shown in Table 1:

[0035] Table 1. Information of main raw materials

[0036]

[0037]

[0038] The test methods adopted in the present invention are as follows:

[0039] (1) Foaming ratio test: The foaming ratio is calculated by density, and the density is tested according to the standard ISO 1183; (2) Compression deformation strength: The test is carried out with reference to GB / T8813-2020.

[0040] The equipment adopted in the present invention:

[0041] High-speed mixer: 120L pot-type high-speed mixer, Suzhou Songyuan Environmental Protection Technology Co., Ltd.

[0042] Twin-screw extruder: The twin-screw extruder used is a product of Coperion GmbH, with the model ZSK32Mc;

[0043] Extrusion foaming equipment: A product of Shandong Tongjia Machinery Co., Ltd., with the model TJ-PLA35 / 65.

[0044] Example 1

[0045] Prepare raw materials with a total mass of 100 kg according to the following weight percentages:

[0046] Polylactic acid PLA L130, 78.5%;

[0047] Polybutylene succinate TH803S-2, 13%;

[0048] Reaction monomer 4,4′-bis(2,3-epoxypropoxy)biphenyl, 1.5%;

[0049] Silane coupling agent 3-isocyanatopropyltriethoxysilane, 1.5%;

[0050] Silica YM-SiO2-20, 5.5%.

[0051] Mix the weighed polybutylene succinate and silane coupling agent evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 25°C, the rotation speed is 200 rpm, and the mixing time is 6 min to obtain a PBS mixture;

[0052] Extrude the above PBS mixture through a twin-screw extruder and pelletize it to obtain a modified PBS material. Among them, the screw temperature is set in sections from the feed port to the head as 170°C, 170°C, 200°C, 200°C, 180°C, 180°C, 175°C, 175°C, 175°C, 170°C, 190°C, and the rotation speed is 300 rpm.

[0053] Mix the weighed polylactic acid, modified PBS, reaction monomer, and silica evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 25°C, the rotation speed is 200 rpm, and the mixing time is 6 min to obtain a PLA mixture;

[0054] Extrude the above PLA mixture through a twin-screw extruder and pelletize it to obtain a modified polylactic acid foaming material. Among them, the screw temperature is set in sections from the feed port to the head as 170°C, 170°C, 200°C, 200°C, 180°C, 180°C, 175°C, 175°C, 175°C, 170°C, 190°C, and the rotation speed is 300 rpm.

[0055] Example 2

[0056] Prepare raw materials with a total mass of 100 kg according to the following weight percentages:

[0057] Polylactic acid PLA FY401, 71.5%;

[0058] Polybutylene succinate TH803S-3, 18%;

[0059] Reaction monomer 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene, 1.5%;

[0060] Silane coupling agent 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, 2%;

[0061] Silica A200, 7%.

[0062] Mix the weighed polybutylene succinate and silane coupling agent evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 30 °C, the rotation speed is 300 rpm, and the mixing time is 7 min to obtain a PBS mixture;

[0063] Extrude the above PBS mixture through a twin-screw extruder and pelletize it to obtain a modified PBS material. Among them, the screw temperature is set in sections from the feed port to the head as 170 °C, 170 °C, 200 °C, 200 °C, 185 °C, 180 °C, 180 °C, 175 °C, 175 °C, 170 °C, 190 °C, and the rotation speed is 400 rpm.

[0064] Mix the weighed polylactic acid, modified PBS, reaction monomer, and silica evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 30 °C, the rotation speed is 300 rpm, and the mixing time is 7 min to obtain a PLA mixture;

[0065] Extrude the above PLA mixture through a twin-screw extruder and pelletize it to obtain a modified polylactic acid foaming material. Among them, the screw temperature is set in sections from the feed port to the head as 170 °C, 170 °C, 200 °C, 200 °C, 185 °C, 180 °C, 180 °C, 175 °C, 175 °C, 170 °C, 190 °C, and the rotation speed is 400 rpm.

[0066] Example 3

[0067] Prepare raw materials with a total mass of 100 kg according to the following weight percentages:

[0068] Polylactic acid PLA REVODE110, 86.5%;

[0069] Polybutylene succinate TH803S-1, 8%;

[0070] Reaction monomer 4,4′-bis(2,3-epoxypropoxy)biphenyl, 1.5%;

[0071] Silane coupling agent 3-isocyanatopropyltrimethoxysilane, 1%;

[0072] Silica XFF31, 3%.

[0073] Weigh the polybutylene succinate and the silane coupling agent, and mix them evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 20 °C, the rotation speed is 100 rpm, and the mixing time is 4 min to obtain a PBS mixture;

[0074] Extrude the above PBS mixture through a twin-screw extruder and pelletize it to obtain a modified PBS material. Among them, the screw temperature is set in sections from the feed port to the head as 170 °C, 170 °C, 190 °C, 190 °C, 190 °C, 190 °C, 175 °C, 175 °C, 175 °C, 170 °C, 180 °C, and the rotation speed is 200 rpm.

[0075] Weigh the polylactic acid, the modified PBS, the reaction monomer, and the silica, and mix them evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 20 °C, the rotation speed is 100 rpm, and the mixing time is 4 min to obtain a PLA mixture;

[0076] Extrude the above PLA mixture through a twin-screw extruder and pelletize it to obtain a modified polylactic acid foaming material. Among them, the screw temperature is set in sections from the feed port to the head as 170 °C, 170 °C, 190 °C, 190 °C, 190 °C, 190 °C, 175 °C, 175 °C, 175 °C, 170 °C, 180 °C, and the rotation speed is 200 rpm.

[0077] Example 4

[0078] Prepare raw materials with a total mass of 100 kg according to the following weight percentages:

[0079] Polylactic acid PLA LX575, 91.5%;

[0080] Polybutylene succinate PZ91PB, 5%;

[0081] Reaction monomer 9,9-bis(4-glycidyloxyphenyl)fluorene, 1.5%;

[0082] Silane coupling agent 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 0.5%;

[0083] Silica YM-SiO2-500, 1.5%.

[0084] Weigh the polybutylene succinate and the silane coupling agent, and mix them evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 10 °C, the rotation speed is 50 rpm, and the mixing time is 3 min to obtain a PBS mixture;

[0085] The above PBS mixture is extruded through a twin-screw extruder and granulated to obtain a modified PBS material. Among them, the screw temperature is set in sections from the feed inlet to the die head as 170 °C, 170 °C, 190 °C, 190 °C, 190 °C, 180 °C, 175 °C, 175 °C, 175 °C, 170 °C, 175 °C, and the rotation speed is 150 rpm.

[0086] Weigh the polylactic acid, modified PBS, reaction monomer, and silica, and mix them evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 10 °C, the rotation speed is 50 rpm, and the mixing time is 3 min to obtain a PLA mixture;

[0087] The above PLA mixture is extruded through a twin-screw extruder and granulated to obtain a modified polylactic acid foaming material. Among them, the screw temperature is set in sections from the feed inlet to the die head as 170 °C, 170 °C, 190 °C, 190 °C, 190 °C, 180 °C, 175 °C, 175 °C, 175 °C, 170 °C, 175 °C, and the rotation speed is 150 rpm.

[0088] Example 5

[0089] Prepare raw materials with a total mass of 100 kg according to the following weight percentages:

[0090] Polylactic acid PLA L105, 65%;

[0091] Polybutylene succinate TH803S-4, 24.5%;

[0092] Reaction monomer 4,4′-bis(2,3-epoxypropoxy)biphenyl, 1.0%;

[0093] Silane coupling agent 3-isocyanatopropyltriethoxysilane, 2.5%;

[0094] Silica A380, 9%.

[0095] Weigh the polybutylene succinate and the silane coupling agent, and mix them evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 40 °C, the rotation speed is 400 rpm, and the mixing time is 8 min to obtain a PBS mixture;

[0096] The above PBS mixture is extruded through a twin-screw extruder and granulated to obtain a modified PBS material. Among them, the screw temperature is set in sections from the feed inlet to the die head as 170 °C, 170 °C, 200 °C, 200 °C, 200 °C, 180 °C, 175 °C, 175 °C, 175 °C, 170 °C, 200 °C, and the rotation speed is 500 rpm.

[0097] Weigh the polylactic acid, modified PBS, reactive monomer, and silica, and mix them evenly in a high-speed mixer. The operating temperature of the high-speed mixer is 40°C, the rotation speed is 400 rpm, and the mixing time is 8 minutes to obtain a PLA mixture.

[0098] Extrude the above PLA mixture through a twin-screw extruder and pelletize it to obtain a modified polylactic acid foaming material. Among them, the screw temperature is set in sections from the feed port to the head as 170°C, 170°C, 200°C, 200°C, 200°C, 180°C, 175°C, 175°C, 175°C, 170°C, 200°C, and the rotation speed is 500 rpm.

[0099] Comparative Example 1

[0100] Prepare the modified polylactic acid foaming material according to the method basically the same as that in Example 1, with the only difference being that no silane coupling agent is added during the preparation process, that is, the raw materials only include the same mass of PLA, PBS, reactive monomer, and silica as in the example.

[0101] Comparative Example 2

[0102] Prepare the modified polylactic acid foaming material according to the method basically the same as that in Example 1, with the only difference being that no silica is added during the preparation process, that is, the raw materials only include the same mass of PLA, PBS, reactive monomer, and silane coupling agent as in the example.

[0103] Comparative Example 3

[0104] Prepare the modified polylactic acid foaming material according to the method basically the same as that in Example 1, with the only difference being that no PBS is added during the preparation process, that is, the raw materials only include the same mass of PLA, reactive monomer, silane coupling agent, and silica as in the example.

[0105] Comparative Example 4

[0106] Prepare the modified polylactic acid foaming material according to the method basically the same as that in Example 1, with the only difference being that no reactive monomer is added during the preparation process, that is, the raw materials only include the same mass of PLA, PBS, silane coupling agent, and silica as in the example.

[0107] Conduct various performance tests on the modified polylactic acid foaming materials prepared in Examples 1 - 5 and Comparative Examples 1 - 5 respectively. The test results are as follows:

[0108] Table 2. Test Results of Product Performance

[0109]

[0110] From the test results of each performance in Table 2, it can be seen that the modified polylactic acid foaming material prepared by the present invention has the characteristics of easy foaming, high foaming ratio, and high compression deformation strength after foaming.

[0111] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the method of the present invention, several improvements and supplements can be made, and these improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A compression-resistant deformation-modified polylactic acid foamed material, characterized in that, Prepared from the following raw material components by weight percentage: Polylactic acid, 65 - 93%; Polybutylene succinate, 5 - 25%; Reaction monomer, 0.5 - 3%; Silane coupling agent, 0.5 - 3%; Filler, 1 - 10%; The reaction monomer is a monomer containing bis - epoxy groups and biphenyl groups; The silane coupling agent is a silane coupling agent containing hydroxyl and / or carboxyl reactive functional groups; The filler is silica.

2. The anti-compression deformation modified polylactic acid foamed material according to claim 1, wherein Prepared from the following raw material components by weight percentage: Polylactic acid, 75 - 88%; Polybutylene succinate, 7 - 20%; Reaction monomer, 1 - 2%; Silane coupling agent, 1 - 2%; Filler, 2 - 8%.

3. The compression-resistant and deformation-modified polylactic acid foamed material according to claim 1, wherein, The melt index of the polylactic acid at 190 °C and 2.16 kg is 3 - 30 g / 10 min.

4. The anti-compression deformation modified polylactic acid foam material according to claim 3, characterized in that The melt index of the polylactic acid at 190 °C and 2.16 kg is 5 - 25 g / 10 min.

5. The anti-compression deformation modified polylactic acid foamed material according to claim 1, wherein, The melt index of the polybutylene succinate at 190 °C and 2.16 kg is 3 - 25 g / 10 min.

6. The anti-compression deformation modified polylactic acid foamed material according to claim 5, characterized in that, The melt index of the polybutylene succinate at 190 °C and 2.16 kg is 5 - 20 g / 10 min.

7. The anti-compression deformation modified polylactic acid foamed material according to claim 1, wherein The reaction monomer is one or more of 4,4′ - bis(2,3 - epoxypropoxy)biphenyl, 9,9 - bis[4-(2,3 - epoxypropoxyethoxy)phenyl]fluorene, 9,9 - bis(4 - epoxypropyloxyphenyl)fluorene.

8. The anti-compression deformation modified polylactic acid foaming material according to claim 1, characterized in that, The silane coupling agent is one or more of 3 - isocyanatopropyltriethoxysilane, 3 - isocyanatopropyltrimethoxysilane, 3 - [(2,3)-epoxypropoxy]propylmethyldimethoxysilane, 3-(2,3 - epoxypropoxy)propyltrimethoxysilane.

9. The anti-compression deformation modified polylactic acid foamed material according to claim 1, wherein The particle size of the filler is 5 nm - 500 nm.

10. The compression-resistant deformation modified polylactic acid foamed material according to claim 9, characterized in that, The particle size of the filler is 10 nm - 100 nm.

11. A method for preparing a compression-resistant deformation-modified polylactic acid foam material as described in any one of claims 1 to 10, characterized in that, Including the following steps: 1) Mix the polybutylene succinate and the silane coupling agent evenly in a high - speed mixer; 2) Extrude and pelletize the mixture obtained in step 1) through a twin - screw extruder to obtain modified PBS; 3) Mix the modified PBS, polylactic acid, reaction monomer, and filler evenly in a high - speed mixer; 4) Extrude and pelletize the mixture obtained in step 3) through a twin - screw extruder to obtain the modified polylactic acid foaming material.

12. The preparation method of the compression-resistant deformation modified polylactic acid foam material according to claim 11, wherein In step 1), the mixing conditions of the high - speed mixer are: temperature is 10 - 40 °C, rotation speed is 50 - 400 rpm, and mixing time is 3 - 8 min.

13. The preparation method of the compression-resistant deformation modified polylactic acid foaming material according to claim 12, characterized in that, In step 1), the mixing conditions of the high - speed mixer are: temperature is 10 - 40 °C, rotation speed is 100 - 300 rpm, and mixing time is 4 - 7 min.

14. The preparation method of the compression-resistant deformation modified polylactic acid foaming material according to claim 11, characterized in that, In step 2), the operating conditions of the twin - screw extruder are: screw temperature is 170 - 200 °C, rotation speed is 150 - 500 rpm.

15. The preparation method of the compression-resistant deformation modified polylactic acid foaming material according to claim 14, wherein In step 2), the operating conditions of the twin - screw extruder are: screw temperature is 175 - 190 °C, rotation speed is 200 - 400 rpm.

16. The preparation method of the compression-resistant deformation modified polylactic acid foam material according to claim 11, wherein In step 3), the mixing conditions of the high - speed mixer are: temperature is 10 - 40 °C, rotation speed is 50 - 400 rpm, and mixing time is 3 - 8 min.

17. The preparation method of the compression-resistant and deformation-modified polylactic acid foamed material according to claim 16, wherein, In step 3), the mixing conditions of the high-speed mixer are as follows: the temperature is 10 - 40°C, the rotation speed is 100 - 300 rpm, and the mixing time is 4 - 7 min.

18. The preparation method of the compression-resistant deformation modified polylactic acid foam material according to claim 11, characterized in that, In step 4), the operating conditions of the twin-screw extruder are as follows: the screw temperature is 170 - 200°C, and the rotation speed is 150 - 500 rpm.

19. The preparation method of the compression-resistant deformation modified polylactic acid foam material according to claim 18, characterized in that, In step 4), the operating conditions of the twin-screw extruder are as follows: the screw temperature is 175 - 190°C, and the rotation speed is 200 - 400 rpm.

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