Preparation method and application of PLA / PBS composite material

Abstract

The invention provides a preparation method and application of a PLAPBS composite material. The PLA / PBS composite material is obtained by melt blending of raw materials including PLA, PBS and a chain extender. The raw materials comprise the following components in parts by weight: 50-90 parts of PLA, 10-50 parts of PBS, 1-9 parts of a chain extender and 0.2-0.8 part of a catalyst; the chain extender is dicyclopentadiene dioxide and / or 4, 4 '-bis (2, 3-epoxypropoxy) biphenyl, and the chain extender is dicyclopentadiene dioxide and / or 4, 4'-bis (2, 3-epoxypropoxy) biphenyl. The PLA / PBS composite material disclosed by the invention has excellent mechanical properties such as tensile strength, impact strength and elongation at break. In addition, the preparation method of the PLA / PBS composite material is simple in process, mild in condition and environment-friendly, and has a very good industrial prospect.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a preparation method and application of a PLA / PBS composite material. Background Art

[0002] Polymer materials have the advantages of low cost, rich functions, and large-scale production, and are widely used in aviation, automobiles, medical care, food and other fields. However, the polymer materials commonly used in production and life currently cause environmental pollution problems due to their difficulty in degradation, so the development of environmentally friendly biodegradable materials is of great significance.

[0003] PLA (polylactic acid) is a biodegradable synthetic polymer material that can be completely degraded into CO2 and H2O by microorganisms in nature after use. At the same time, PLA has excellent biocompatibility and can be processed in a variety of ways, such as extrusion, spinning, biaxial stretching, injection blow molding and other processing techniques. However, PLA has certain defects in performance, such as brittleness, poor impact resistance, poor processing thermal stability and poor gas barrier properties.

[0004] PBS (polybutylene succinate) contains easily hydrolyzed ester groups in its structural units, which are easily decomposed and metabolized by various microorganisms or enzymes in animals and plants in nature, and finally form CO2 and H2O. It is a typical fully biodegradable polymer material with good biocompatibility and bioabsorbability. At the same time, the chain structure of PBS determines its mechanical and physical properties. It is suitable for blown film and hollow containers, extrusion processing sheets, spinning, injection molding and other processing technologies, and can be used to prepare various fully biodegradable polymer products. However, the common PBS has a low molecular weight, low processing temperature and low viscosity, which makes the mechanical properties of the material poor.

[0005] PLA and PBS are blended to prepare PLA / PBS composite materials. On the one hand, the material does not lose its biodegradable properties. On the other hand, PBS will have a certain toughening effect on PLA. Moreover, the processing operation is simple when PBS is blended with PLA, and the instrument is easy to clean. In addition, PLA / PBS composite materials also have certain advantages in tensile strength. Therefore, PLA / PBS composite materials are a very popular research direction at present. However, PLA and PBS have extremely poor compatibility, which affects the processability of the material. At present, the most widely used compatibilizer for PLA and PBS is polycyclic epoxy chain extender (ADR), which contains active epoxy functional groups in its structure. However, the monomers of ADR are all derived from petroleum monomers and are non-renewable. Excessive addition will make the degradable properties of PLA / PBS composite materials worse, and the choice of chain extender has a greater impact on the performance of the composite material. It is impossible to achieve the simultaneous improvement of tensile strength and toughness (impact strength and elongation at break) of PLA / PBS composite materials. Therefore, how to balance tensile strength and toughness to meet the performance requirements of the application is also a considerable challenge. Therefore, further optimization research on PLA / PBS composite materials is needed. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problems of poor compatibility and poor mechanical properties of PLA and PBS materials, and further provide a preparation method and application of a PLA / PBS composite material.

[0007] In order to achieve the above technical objectives, the technical solutions adopted in this application are as follows:

[0008] In a first aspect, the present invention provides a PLA / PBS composite material, which is obtained by melt blending raw materials PLA, PBS and a chain extender; the raw materials comprise, by weight, 50-90 parts of PLA, 10-50 parts of PBS, 1-9 parts of a chain extender, and 0.2-0.8 parts of a catalyst; the chain extender is dicyclopentadiene dioxide and / or 4,4'-bis(2,3-epoxypropoxy)biphenyl.

[0009] Preferably, the chain extender is dicyclopentadiene dioxide, and the raw materials of the composite material are composed of 65-75 parts of PLA, 30-35 parts of PBS, 3-4 parts of chain extender, and 0.6-0.7 parts of catalyst in parts by weight; more preferably, the raw materials of the composite material are composed of 70 parts of PLA, 30 parts of PBS, 4 parts of chain extender, and 0.6 parts of catalyst in parts by weight.

[0010] Preferably, the chain extender is 4,4'-bis(2,3-epoxypropoxy)biphenyl, and the raw materials of the composite material are composed of 65-75 parts of PLA, 30-35 parts of PBS, 6-7 parts of chain extender, and 0.3-0.4 parts of catalyst in parts by weight; more preferably, the raw materials of the composite material are composed of 70 parts of PLA, 30 parts of PBS, 6 parts of chain extender, and 0.6 parts of catalyst in parts by weight.

[0011] Preferably, the chain extender is dicyclopentadiene dioxide and 4,4'-bis(2,3-epoxypropoxy)biphenyl, and the raw materials of the composite material are composed of 65-75 parts of PLA, 30-35 parts of PBS, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, and 0.5-0.6 parts of catalyst; more preferably, the raw materials of the composite material are composed of 70 parts of PLA, 30 parts of PBS, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, and 0.6 parts of catalyst.

[0012] Preferably, the raw material further comprises 1 to 5 parts of an auxiliary compatibilizer, more preferably 1 to 2 parts, and the auxiliary compatibilizer is propylene glycol diacetate (PGDA).

[0013] Preferably, the catalyst is stannous octoate.

[0014] In a second aspect, the present invention provides a method for preparing the PLA / PBS composite material described in the first aspect, characterized by comprising: blending ingredients according to the raw material composition of the PLA / PBS composite material and then extruding.

[0015] Preferably, the control parameters of the blending are: blending temperature is 160-220° C., blending speed is 40-100 rpm, and blending time is 1-10 min.

[0016] More preferably, the control parameters of the blending are: blending temperature is 180±5° C., blending speed is 60-80 rpm, and blending time is 4-6 min.

[0017] In a third aspect, the present invention provides use of the PLA / PBS composite material described in the first aspect in preparing a film product.

[0018] The film product belongs to the packaging field, the agricultural field and the biomedical field.

[0019] The present invention has the following advantages:

[0020] The PLA / PBS composite material provided by the present invention adopts 4,4'-bis(2,3-epoxypropoxy)biphenyl and / or dicyclopentadiene dioxide as a composite chain extender during its preparation process. The functional groups on the molecular chains of the two chain extenders react with the terminal functional groups of PLA and PBS to form chain extension polymers of PLA and PBS at both ends, which can improve the mechanical properties and process properties of the material in the composite system, and can also greatly increase the compatibility between the two phases of PLA and PBS. In addition, the present invention preferably adopts propylene glycol diacetate (PGDA) as an auxiliary compatibilizer, which helps to further increase the compatibilization between the two phases of PLA and PBS. The obtained PLA / PBS composite material has excellent tensile strength, impact strength, and mechanical properties such as elongation at break. In addition, the preparation method of the PLA / PBS composite material is simple in process, mild in conditions, environmentally friendly, and has good industrial prospects. DETAILED DESCRIPTION

[0021] In the description of the present invention, it should be noted that, if the specific conditions are not specified in the examples, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0022] In a specific embodiment of the present invention, when 4,4'-bis(2,3-epoxypropoxy)biphenyl is used as a chain extender in a PLA / PBS composite material, the main reaction between PLA, PBS and the chain extender is shown in the following reaction equation 1. The components that may exist in the PLA / PBS composite material are:

[0023] 1) PLA;

[0024] 2) PBS;

[0025]

[0026]

[0027] Reaction equation 1:

[0028]

[0029] When dicyclopentadiene dioxide is used as a chain extender in the PLA / PBS composite material, the main reaction between PLA, PBS and the chain extender is shown in the following reaction equation 2. The possible components in the PLA / PBS composite material are:

[0030] 1) PLA;

[0031] 2) PBS;

[0032]

[0033] Reaction equation 2:

[0034]

[0035] When dicyclopentadiene dioxide and 4,4'-bis(2,3-epoxypropoxy)biphenyl are used as chain extenders at the same time, the possible components in the PLA / PBS composite material are:

[0036]

[0037]

[0038] The present invention is further illustrated below through the description of specific implementation modes, but this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not deviate from the basic idea of ​​the present invention, they are all within the scope of the present invention.

[0039] Example 1

[0040] The present embodiment provides a PLA / PBS composite material, and the following raw materials are selected in parts by weight: 90 parts of PLA material, 10 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate.

[0041] The above materials are mixed in a mixer and granulated by twin-screw extrusion. The control parameters of the blending are: blending temperature is 180±5°C, blending speed is 70rpm, and blending time is 5min.

[0042] Example 2

[0043] This embodiment provides a PLA / PBS composite material, and the following raw materials are selected in parts by weight: 90 parts of PLA material, 10 parts of PBS material, 1 part of dicyclopentadiene dioxide, 6 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0044] Example 3

[0045] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 90 parts of PLA material, 10 parts of PBS material, 3 parts of dicyclopentadiene dioxide, 4 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0046] Example 4

[0047] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 90 parts of PLA material, 10 parts of PBS material, 4 parts of dicyclopentadiene dioxide, 3 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0048] Example 5

[0049] This embodiment provides a PLA / PBS composite material, wherein the raw materials are selected in the following weight proportions: 70 parts of PLA material, 30 parts of PBS material, 4 parts of dicyclopentadiene dioxide, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of embodiment 1.

[0050] Example 6

[0051] This embodiment provides a PLA / PBS composite material, wherein the raw materials are selected in the following weight proportions: 70 parts of PLA material, 30 parts of PBS material, 3 parts of dicyclopentadiene dioxide, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of embodiment 1.

[0052] Example 7

[0053] This embodiment provides a PLA / PBS composite material, wherein the raw materials are selected in the following weight proportions: 70 parts of PLA material, 30 parts of PBS material, 5 parts of dicyclopentadiene dioxide, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of embodiment 1.

[0054] Example 8

[0055] This embodiment provides a PLA / PBS composite material, wherein the raw materials are selected in the following weight proportions: 70 parts of PLA material, 30 parts of PBS material, 6 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of embodiment 1.

[0056] Example 9

[0057] This embodiment provides a PLA / PBS composite material, wherein the raw materials are selected in the following weight proportions: 70 parts of PLA material, 30 parts of PBS material, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of embodiment 1.

[0058] Example 10

[0059] This embodiment provides a PLA / PBS composite material, wherein the raw materials are selected in the following weight proportions: 70 parts of PLA material, 30 parts of PBS material, 7 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of embodiment 1.

[0060] Embodiment 11

[0061] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 80 parts of PLA material, 20 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0062] Example 12

[0063] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 70 parts of PLA material, 30 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0064] Example 13

[0065] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 60 parts of PLA material, 40 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 2 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0066] Embodiment 14

[0067] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 70 parts of PLA material, 30 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 1 part of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0068] Embodiment 15

[0069] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 70 parts of PLA material, 30 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 3 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0070] Example 16

[0071] This embodiment provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 70 parts of PLA material, 30 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, 4 parts of PGDA material, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0072] Comparative Example 1

[0073] This comparative example provides a PLA / PBS composite material, wherein the raw materials are selected in the following weight proportions: 70 parts of PLA material and 30 parts of PBS material. The preparation method is the same as that of Example 1.

[0074] Comparative Example 2

[0075] This comparative example provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 70 parts of PLA material, 30 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, and 0.6 parts of stannous octoate. The preparation method is the same as that of Example 1.

[0076] Comparative Example 3

[0077] This comparative example provides a PLA / PBS composite material, which is prepared by selecting the following raw materials in parts by weight: 70 parts of PLA material, 30 parts of PBS material, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, and 2 parts of PGDA material. The preparation method is the same as that of Example 1.

[0078] The tensile strength, impact strength and elongation at break of the PLA / PBS composite materials of Examples 1 to 16 and Comparative Examples 1 to 3 were tested. The results are shown in Table 1.

[0079] Table 1 Test results of PLA / PBS composite materials of Examples 1 to 16 and Comparative Examples 1 to 3

[0080]

[0081]

[0082] It can be seen from the data in Table 1 that the PLA / PBS composite material obtained in the embodiment of the present invention has better toughness (impact strength and elongation at break) than the existing simply compounded PLA / PBS composite material (Comparative Example 1) and the PLA / PBS composite material without adding the auxiliary compatibilizer PGDA (Comparative Example 2), and the tensile strength of the PLA / PBS composite material obtained in all embodiments can reach more than 40MPa, and the impact strength can reach 4.5kJ / m 2Above, the elongation at break reaches more than 250%, and the tensile strength and toughness are well balanced to meet the performance requirements of the application. Comparative Example 3 is a PLA / PBS composite material obtained by directly mixing PLA, PBS, chain extender, and compatibilizer in the absence of a catalyst. It can be seen from its performance data that the comprehensive performance of the PLA / PBS composite material has not been improved in the absence of a catalyst. In addition, in all embodiments of the present invention, it can be seen that the PLA / PBS composite material obtained when two chain extenders, dicyclopentadiene dioxide and 4,4'-bis(2,3-epoxypropoxy)biphenyl, are used at the same time has better performance, wherein the ratio of PLA and PBS is controlled at 70 parts: 30 parts, dicyclopentadiene dioxide and 4,4'-bis(2,3-epoxypropoxy)biphenyl are 2 parts and 5 parts respectively to obtain the optimal performance results. In addition, the amount of PGDA used also has a certain effect on the performance of the PLA / PBS composite material, and it is better to control it at 1 to 2 parts.

[0083] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A PLA / PBS composite material, characterized in that: The PLA / PBS composite material is obtained by melt blending raw materials of PLA, PBS and a chain extender; the raw materials comprise, by weight, 50 to 90 parts of PLA, 10 to 50 parts of PBS, 1 to 9 parts of a chain extender and 0.2 to 0.8 parts of a catalyst; the chain extender is dicyclopentadiene dioxide and / or 4,4'-bis(2,3-epoxypropoxy)biphenyl.

2. The PLA / PBS composite material according to claim 1, characterized in that: The chain extender is dicyclopentadiene dioxide, and the raw materials of the composite material are composed of 65-75 parts of PLA, 30-35 parts of PBS, 3-4 parts of chain extender, and 0.6-0.7 parts of catalyst in parts by weight; preferably, the raw materials of the composite material are composed of 70 parts of PLA, 30 parts of PBS, 4 parts of chain extender, and 0.6 parts of catalyst in parts by weight.

3. The PLA / PBS composite material according to claim 1, characterized in that: The chain extender is 4,4'-bis(2,3-epoxypropoxy)biphenyl, and the raw materials of the composite material are composed of 65-75 parts of PLA, 30-35 parts of PBS, 6-7 parts of chain extender, and 0.3-0.4 parts of catalyst in parts by weight; preferably, the raw materials of the composite material are composed of 70 parts of PLA, 30 parts of PBS, 6 parts of chain extender, and 0.6 parts of catalyst in parts by weight.

4. The PLA / PBS composite material according to claim 1, characterized in that: The chain extender is dicyclopentadiene dioxide and 4,4'-bis(2,3-epoxypropoxy)biphenyl, and the raw materials of the composite material are composed of 65-75 parts of PLA, 30-35 parts of PBS, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, and 0.5-0.6 parts of catalyst in parts by weight; preferably, the raw materials of the composite material are composed of 70 parts of PLA, 30 parts of PBS, 2 parts of dicyclopentadiene dioxide, 5 parts of 4,4'-bis(2,3-epoxypropoxy)biphenyl, and 0.6 parts of catalyst in parts by weight.

5. The PLA / PBS composite material according to any one of claims 1 to 4, characterized in that: The raw material also includes 1 to 5 parts of an auxiliary compatibilizer, preferably 1 to 2 parts, and the auxiliary compatibilizer is propylene glycol diacetate (PGDA).

6. The PLA / PBS composite material according to any one of claims 1 to 5, characterized in that: The catalyst is stannous octoate.

7. The method for preparing the PLA / PBS composite material according to any one of claims 1 to 6, characterized in that: include: The raw materials of the PLA / PBS composite material are mixed and then extruded.

8. The preparation method according to claim 7, characterized in that: The control parameters of the blending are: blending temperature is 160-220° C., blending speed is 40-100 rpm, and blending time is 1-10 min.

9. The preparation method according to claim 8, characterized in that: The control parameters of the blending are: blending temperature is 180±5° C., blending speed is 60-80 rpm, and blending time is 4-6 min.

10. Use of the PLA / PBS composite material according to any one of claims 1 to 6 in preparing film products.

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