A compatibilized modified PBAT / PLA / plasticized starch composite material and a preparation method thereof

Abstract

The application belongs to the technical field of high polymer materials, and particularly discloses a compatilized modified PBAT / PLA / plasticized starch composite material and a preparation method thereof.The preparation raw material of the compatilized modified PBAT / PLA / plasticized starch composite material comprises PBAT, PLA, plasticized starch and a compatilizer.The plasticized starch is oxamide modified starch.The compatilizer is a 3,4-epoxy-1-butene graft of PBAT.The compatilized modified PBAT / PLA / plasticized starch composite material has high tensile strength and elastic modulus, and excellent mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and particularly relates to a compatibly modified PBAT / PLA / plasticized starch composite material and a preparation method thereof. BACKGROUND

[0002] Polybutylene adipate terephthalate (PBAT) is a kind of completely biodegradable high polymer material with butylene terephthalate (BT) and butylene adipate (BA) as random repeating units. PBAT has high elongation at break, good processability, and good toughness, etc. However, the melt strength, elastic modulus and tensile strength of PBAT are poor, which limits its application. Poly lactic acid (PLA) has sufficient strength and rigidity, and by adding PLA into PBAT, the strength and rigidity and other mechanical properties of PBAT can be improved. Starch has a low price and can be biodegraded, so by blending starch with PBAT and PLA, the production cost of the material can be reduced. By blending PBAT, PLA and starch, the respective advantages of them can be fully exerted.

[0003] However, there are still problems in preparing the PBAT / PLA / starch composite material. For example, the decomposition temperature of starch is much lower than the melting temperature, and when heated, the starch is decomposed before reaching the melting point of the starch, and the processability is poor. Therefore, the starch needs to be plasticized and modified to form plasticized starch, so that the crystallization performance of the starch is reduced and the melting temperature is lowered, so that the starch can be melted before decomposition and thus can be processed and formed. In addition, the starch contains a large number of hydroxyl groups and is hydrophilic, and PLA and PBAT only have a small amount of hydroxyl groups and are hydrophobic, so the compatibility of starch with PLA and PBAT is poor, and the solubility parameters of PLA and PBAT differ by more than 10, so the compatibility of PLA and PBAT is also poor. How to improve the compatibility of PBAT, PLA and starch to fully exert the excellent performance of PLA, PBAT and starch is still a problem to be solved.

[0004] Based on the above problems, the present application provides a compatibly modified PBAT / PLA / plasticized starch composite material to improve the performance of the PBAT / PLA / plasticized starch composite material. SUMMARY

[0005] The present application aims to provide a compatibly modified PBAT / PLA / plasticized starch composite material and a preparation method thereof.

[0006] To achieve the above object, the present application adopts the following technical solutions.

[0007] In a first aspect, the application provides a compatibilized modified PBAT / PLA / plasticized starch composite material, and the preparation raw materials include: PBAT, PLA, plasticized starch, and a compatibilizer.

[0008] The plasticized starch is oxamide-modified starch.

[0009] The compatibilizer is a 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB), and the structural formula of PBAT-g-EPB is as follows:

[0010]

[0011] The grafting rate of the 3,4-epoxy-1-butene graft of PBAT is 0.5-1.2.

[0012] As an embodiment of the application, in the preparation raw materials, the weight fractions of PBAT, PLA, plasticized starch, and the compatibilizer are as follows:

[0013] PBAT 50-90 parts

[0014] PLA 10-50 parts

[0015] Plasticized starch 10-40 parts

[0016] Compatibilizer 0.01-2.0 parts.

[0017] As an embodiment of the application, in the preparation raw materials, the amount of plasticized starch is 10-30 parts.

[0018] As an embodiment of the application, in the preparation raw materials, the amount of the compatibilizer is 0.01-0.10 parts.

[0019] As an embodiment of the application, the preparation method of the plasticized starch includes: mixing starch and oxamide, and then extruding by a double-screw extruder to obtain the plasticized starch. The mass ratio of the starch to the oxamide is 100:(15-35).

[0020] As an embodiment of the application, in the preparation process of the plasticized starch, the mixing temperature of the starch and the oxamide is 70-90°C, and the extrusion temperature of the double-screw extruder is 140-160°C.

[0021] As an embodiment of the application, after the starch and the oxamide are mixed, the mixture is first dried, and then extruded by a double-screw extruder. The drying temperature is 75-90°C, and the drying is performed under vacuum conditions.

[0022] As an embodiment of the present application, the preparation method of the 3,4-epoxy-1-butene graft of the PBAT comprises: melt blending the PBAT with 3,4-epoxy-1-butene and an initiator to obtain the 3,4-epoxy-1-butene graft of the PBAT.

[0023] As an embodiment of the present application, the initiator is dicumyl peroxide (DCP) and / or dibenzoyl peroxide (BPO).

[0024] As an embodiment of the present application, the temperature of the melt blending in the preparation process of the 3,4-epoxy-1-butene graft of the PBAT is 130-170℃.

[0025] As an embodiment of the present application, the number average molecular weight of the PBAT is 40000-60000.

[0026] As an embodiment of the present application, the number average molecular weight of the PLA is 50000-80000.

[0027] In a second aspect, the present application provides a preparation method of a compatibilized modified PBAT / PLA / plasticized starch composite material, comprising the step of: melt blending PBAT, PLA, plasticized starch and a compatibilizer to obtain the compatibilized modified PBAT / PLA / plasticized starch composite material.

[0028] In a third aspect, the present application provides an application of a compatibilized modified PBAT / PLA / plasticized starch composite material. The compatibilized modified PBAT / PLA / plasticized starch composite material provided by the present application has high tensile strength and elastic modulus, and excellent mechanical properties, and can be used in blown film products such as preservative films, mulching films and various packaging films.

[0029] The compatibilized modified PBAT / PLA / plasticized starch composite material provided by the present application uses a PBAT-g-EPB graft prepared by a melt method as a compatibilizer, uses oxamide modified starch as plasticized starch, and melt blends with PBAT and PLA to obtain a compatibilized modified PBAT / PLA / plasticized starch composite material.

[0030] In the present application, the adopted compatibilizer PBAT-g-EPB graft is a degradable compatibilizer, which contains a large number of epoxy side groups. The epoxy groups on the compatibilizer can react with the terminal carboxyl groups and terminal hydroxyl groups of PBAT and PLA, effectively improving the compatibility between PBAT, PLA and plasticized starch, and realizing the improvement of the mechanical properties such as elastic modulus and tensile strength of the composite material. The oxamide is used for plasticizing modification of starch to improve the processability of starch, and the starch is applied to the PBAT / PLA composite system, which not only effectively reduces the production cost of the composite material, but also plays a compatibilizing role in the PLA, PBAT and starch composite system. The compatibilized and modified PBAT / PLA / plasticized starch composite material provided by the present application has high tensile strength and elastic modulus, and excellent mechanical properties. DETAILED DESCRIPTION

[0031] The technical solutions of the present application are described in detail below. Those skilled in the art should understand that the specific embodiments are only to help understand the present application, and should not be regarded as a specific limitation of the present application.

[0032] It should be noted that, unless specifically indicated, the technical means used in the following examples is the conventional means familiar to those skilled in the art. When not specifically stated, the raw materials used in the present application are all conventional commercial goods, which can be obtained by purchase.

[0033] The present application provides a compatibilized and modified PBAT / PLA / plasticized starch composite material, and the preparation raw materials include: PBAT, PLA, plasticized starch and compatibilizer; the plasticized starch is oxamide modified starch; and the compatibilizer is a 3,4-epoxy-1-butene graft of PBAT.

[0034] Preferably, in the compatibilized and modified PBAT / PLA / plasticized starch composite material, the weight fractions of PBAT, PLA, plasticized starch and compatibilizer in the preparation raw materials are respectively:

[0035] PBAT 50-90 parts

[0036] PLA 10-50 parts

[0037] Plasticized starch 10-40 parts

[0038] Compatibilizer 0.01-2.0 parts.

[0039] In the present application, the preparation method of the plasticized starch comprises: mixing starch and oxalylamide, and then extruding by a double screw extruder to obtain the plasticized starch. The starch and the oxalylamide are mixed at a mass ratio of 100:(15-35). Specifically, the starch and the oxalylamide can be mixed at a mass ratio of 100:15, 100:20, 100:25, 100:30, 100:35 or any other ratio within the range of 100:(15-35).

[0040] In the present application, the mixing temperature of the starch and the oxalylamide is 70-90℃. Specifically, the mixing temperature can be 70℃, 75℃, 80℃, 85℃, 90℃ or any other temperature within the range of 70-90℃.

[0041] In the present application, the extrusion temperature of the double screw extruder during the preparation of the plasticized starch is 140-160℃. Specifically, the extrusion temperature can be 140℃, 145℃, 150℃, 155℃, 160℃ or any other temperature within the range of 140-160℃.

[0042] In the present application, after the starch and the oxalylamide are mixed, they are first dried and then extruded by a double screw extruder. The drying temperature is 75-90℃, and the drying is carried out under vacuum conditions, and the drying time is 8-12h. Specifically, the drying temperature can be 75℃, 80℃, 85℃, 90℃ or any other temperature within the range of 75-90℃.

[0043] In the present application, the preparation method of the 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB) comprises: melt blending PBAT, 3,4-epoxy-1-butene and an initiator to prepare the 3,4-epoxy-1-butene graft of PBAT.

[0044] In the present application, the preparation method of the 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB) comprises: melt blending PBAT, 3,4-epoxy-1-butene and an initiator to prepare the 3,4-epoxy-1-butene graft of PBAT.

[0045] In the present application, the preparation method of the 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB) comprises: melt blending PBAT, 3,4-epoxy-1-butene and an initiator to prepare the 3,4-epoxy-1-butene graft of PBAT.

[0046] The initiator used in the application is dicumyl peroxide (DCP) and / or dibenzoyl peroxide (BPO).

[0047] In the application, the temperature of melt blending is 130-170℃ when preparing the 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB).

[0048] In the application, the number average molecular weight of the PBAT used is 40000-60000.

[0049] In the application, the number average molecular weight of the PLA used is 50000-80000.

[0050] The application provides a preparation method of the composite material, which comprises the following steps: melt blending PBAT, PLA, plasticized starch and a compatibilizer to obtain a compatibly modified PBAT / PLA / plasticized starch composite material.

[0051] The application will be described in detail below through specific examples.

[0052] Example 1

[0053] The example provides a compatibly modified PBAT / PLA / plasticized starch composite material, and the preparation raw materials are PBAT, PLA, plasticized starch and a compatibilizer.

[0054] In the preparation raw materials, the weight parts of the PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0055]

[0056] The number average molecular weight of the raw material PLA is 50000.

[0057] The raw material PBAT for preparing the composite material is the same as the raw material PBAT for preparing the compatibilizer, and the number average molecular weight is 50000.

[0058] The preparation method of the plasticized starch is as follows: starch and oxalamide are weighed according to a mass ratio of 100:30, then added into a high-speed blender for mixing, the temperature of the high-speed blender is 80 DEG C, and the rotating speed is 1200 r / min; then the mixture is sealed with a sealed bag and placed in a vacuum drying box at 80 DEG C for 12 hours, and then added into a double-screw extruder for melt blending, the temperature of the double-screw extruder is 150 DEG C, and the rotating speed is 50 r / min, to obtain the plasticized starch.

[0059] The preparation method of the compatibilizer PBAT-g-EPB is as follows: 100 parts by weight of PBAT, 0.7 parts by weight of 3,4-epoxy-1-butene, and 1.4 parts by weight of initiator dicumyl peroxide (DCP) are weighed; the PBAT, 3,4-epoxy-1-butene, and DCP are added into a double-screw extruder for melt blending, the temperature of the melt blending is 150 DEG C, and the rotating speed of the double-screw extruder is 50 r / min, to obtain the PBAT-g-EPB with a grafting rate of 0.53.

[0060]

[0061] The preparation method of the compatibilized modified PBAT / PLA / plasticized starch composite material provided in the embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added into a double-screw extruder for melt blending, the temperature of the melt blending of the double-screw extruder is 150 DEG C, and the rotating speed is 50 r / min, to obtain the PBAT-g-EPB compatibilized modified PBAT / PLA / plasticized starch composite material.

[0062] Example 2

[0063] The embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, and the preparation raw materials are as follows: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide modified starch; and the compatibilizer is a 3,4-epoxy-1-butene grafting product (PBAT-g-EPB) of PBAT.

[0064] In the preparation raw materials, the parts by weight of PBAT, PLA, plasticized starch, and the compatibilizer are as follows:

[0065]

[0066] The raw materials PLA, PBAT, and plasticized starch are the same as those in the embodiment 1.

[0067] The preparation method of the compatibilizer PBAT-g-EPB is as follows: 100 parts by weight of PBAT, 0.7 parts by weight of 3,4-epoxy-1-butene and 1.4 parts by weight of initiator benzoyl peroxide (BPO) are weighed; the PBAT, 3,4-epoxy-1-butene and BPO are added to a twin-screw extruder for melt blending, the temperature for melt blending is 150 DEG C, the rotating speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is extruded, with a grafting rate of 0.61. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Embodiment 1.

[0068] The compatibly modified PBAT / PLA / plasticized starch composite material provided in the embodiment is prepared by adding PBAT, PLA, plasticized starch and PBAT-g-EPB into a twin-screw extruder for melt blending, the temperature for melt blending of the twin-screw extruder is 150 DEG C, and the rotating speed is 50 r / min.

[0069] Embodiment 3

[0070] The compatibly modified PBAT / PLA / plasticized starch composite material provided in the embodiment is prepared by adding PBAT, PLA, plasticized starch and PBAT-g-EPB into a twin-screw extruder for melt blending, the temperature for melt blending of the twin-screw extruder is 150 DEG C, and the rotating speed is 50 r / min.

[0071] In the preparation raw materials, the parts by weight of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0072]

[0073] The raw materials PLA, PBAT and plasticized starch are the same as those in Embodiment 1.

[0074] The preparation method of the compatibilizer PBAT-g-EPB is as follows: 100 parts by weight of PBAT, 0.7 parts by weight of 3,4-epoxy-1-butene and 1.4 parts by weight of initiator benzoyl peroxide (BPO) are weighed; the PBAT, 3,4-epoxy-1-butene and BPO are added to a twin-screw extruder for melt blending, the temperature for melt blending is 150 DEG C, the rotating speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is extruded, with a grafting rate of 0.61. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Embodiment 1.

[0075] The compounding modified PBAT / PLA / plasticized starch composite material provided in the embodiment has a preparation method that: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added into a double screw extruder in weight fractions, melt blending is performed, the temperature of the melt blending of the double screw extruder is 150 DEG C, and the rotating speed is 50 r / min, and a PBAT-g-EPB compounding modified PBAT / PLA / plasticized starch composite material is prepared.

[0076] Embodiment 4

[0077] The compounding modified PBAT / PLA / plasticized starch composite material provided in the embodiment has a preparation method that: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added into a double screw extruder in weight fractions, melt blending is performed, the temperature of the melt blending of the double screw extruder is 150 DEG C, and the rotating speed is 50 r / min, and a PBAT-g-EPB compounding modified PBAT / PLA / plasticized starch composite material is prepared.

[0078] In the preparation raw materials, the weight fractions of PBAT, PLA, plasticized starch, and compounding agent are respectively:

[0079]

[0080] The raw materials PLA, PBAT, and plasticized starch are the same as in Embodiment 1.

[0081] The preparation method of the compounding agent PBAT-g-EPB is: 100 weight parts of PBAT, 0.7 weight parts of 3,4-epoxy-1-butene, and 2.8 weight parts of initiator BPO are weighed; the PBAT, 3,4-epoxy-1-butene, and BPO are added into a double screw extruder, melt blending is performed, the temperature of the melt blending is 150 DEG C, the rotating speed of the double screw extruder is 50 r / min, PBAT-g-EPB is extruded, and the grafting rate is 0.84. The reaction formula involved in the preparation of the compounding agent PBAT-g-EPB is the same as in Embodiment 1.

[0082] The compounding modified PBAT / PLA / plasticized starch composite material provided in the embodiment has a preparation method that: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added into a double screw extruder in weight fractions, melt blending is performed, the temperature of the melt blending of the double screw extruder is 150 DEG C, and the rotating speed is 50 r / min, and a PBAT-g-EPB compounding modified PBAT / PLA / plasticized starch composite material is prepared.

[0083] Embodiment 5

[0084] The embodiment provides a compatilization modified PBAT / PLA / plasticized starch composite material, and preparation raw materials are as follows: PBAT, PLA, plasticized starch and a compatilization agent; the plasticized starch is oxamide modified starch; and the compatilization agent is a 3,4-epoxy-1-butene graft (PBAT-g-EPB) of PBAT.

[0085] In the preparation raw materials, the weight parts of PBAT, PLA, plasticized starch and the compatilization agent are respectively as follows:

[0086]

[0087] The raw materials PLA, PBAT and plasticized starch are the same as those in the embodiment 1.

[0088] The preparation method of the compatilization agent PBAT-g-EPB is as follows: 100 parts by weight of PBAT, 1.4 parts by weight of 3,4-epoxy-1-butene and 2.8 parts by weight of an initiator DCP are weighed; the PBAT, 3,4-epoxy-1-butene and DCP are added into a double-screw extruder to perform melt blending, the temperature of melt blending is 150 DEG C, the rotating speed of the double-screw extruder is 50 r / min, and PBAT-g-EPB is obtained through extrusion, and the grafting rate is 1.15. The reaction formula related to the preparation of the compatilization agent PBAT-g-EPB is the same as that in the embodiment 1.

[0089] The preparation method of the compatilization modified PBAT / PLA / plasticized starch composite material provided in the embodiment is as follows: the PBAT, PLA, plasticized starch and PBAT-g-EPB are added into a double-screw extruder according to weight parts, melt blending is performed, the temperature of melt blending of the double-screw extruder is 150 DEG C, and the rotating speed is 50 r / min, and the compatilization modified PBAT / PLA / plasticized starch composite material is prepared.

[0090] Embodiment 6

[0091] The embodiment provides a compatilization modified PBAT / PLA / plasticized starch composite material, and preparation raw materials are as follows: PBAT, PLA, plasticized starch and a compatilization agent; the plasticized starch is oxamide modified starch; and the compatilization agent is a 3,4-epoxy-1-butene graft (PBAT-g-EPB) of PBAT.

[0092] In the preparation raw materials, the weight parts of PBAT, PLA, plasticized starch and the compatilization agent are respectively as follows:

[0093]

[0094]

[0095] The raw materials PLA, PBAT and plasticized starch are the same as those in the embodiment 1.

[0096] The preparation method of the compatibilizer PBAT-g-EPB is as follows: 100 parts by weight of PBAT, 1.4 parts by weight of 3,4-epoxy-1-butene, and 2.8 parts by weight of initiator BPO are weighed; the PBAT, 3,4-epoxy-1-butene, and BPO are added to a twin-screw extruder for melt blending, the temperature for melt blending is 150°C, the rotating speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is obtained by extrusion, with a grafting rate of 1.19. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Embodiment 1.

[0097] The compatibly modified PBAT / PLA / plasticized starch composite material provided in the embodiment is prepared by adding PBAT, PLA, plasticized starch, and PBAT-g-EPB into a twin-screw extruder for melt blending, the temperature for melt blending of the twin-screw extruder is 150°C, and the rotating speed is 50 r / min.

[0098] Embodiment 7

[0099] The compatibly modified PBAT / PLA / plasticized starch composite material provided in the embodiment is prepared by adding PBAT, PLA, plasticized starch, and PBAT-g-EPB into a twin-screw extruder for melt blending, the temperature for melt blending of the twin-screw extruder is 150°C, and the rotating speed is 50 r / min.

[0100] In the preparation raw materials, the parts by weight of PBAT, PLA, plasticized starch, and compatibilizer are respectively:

[0101]

[0102]

[0103] The raw materials PLA, PBAT, and plasticized starch are the same as in Embodiment 1.

[0104] The compatibilizer PBAT-g-EPB is the same as in Embodiment 6.

[0105] The compatibly modified PBAT / PLA / plasticized starch composite material provided in the embodiment is prepared by adding PBAT, PLA, plasticized starch, and PBAT-g-EPB into a twin-screw extruder for melt blending, the temperature for melt blending of the twin-screw extruder is 150°C, and the rotating speed is 50 r / min.

[0106] Embodiment 8

[0107] The embodiment provides a compatilized modified PBAT / PLA / plasticized starch composite material, and preparation raw materials are as follows: PBAT, PLA, plasticized starch and a compatilizer; the plasticized starch is oxamide modified starch; and the compatilizer is a 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB).

[0108] In the preparation raw materials, the weight parts of PBAT, PLA, plasticized starch and the compatilizer are respectively as follows:

[0109]

[0110] The raw materials PLA, PBAT and plasticized starch are the same as those in the embodiment 1.

[0111] The compatilizer PBAT-g-EPB is the same as that in the embodiment 6.

[0112] The preparation method of the compatilized modified PBAT / PLA / plasticized starch composite material provided in the embodiment is as follows: the PBAT, PLA, plasticized starch and PBAT-g-EPB are added into a double-screw extruder according to weight parts, melt blending is carried out, the temperature of melt blending of the double-screw extruder is 150 DEG C, and the rotating speed is 50 r / min, so that the PBAT-g-EPB compatilized modified PBAT / PLA / plasticized starch composite material is prepared.

[0113] Embodiment 9

[0114] The embodiment provides a compatilized modified PBAT / PLA / plasticized starch composite material, and preparation raw materials are as follows: PBAT, PLA, plasticized starch and a compatilizer; the plasticized starch is oxamide modified starch; and the compatilizer is a 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB).

[0115] In the preparation raw materials, the weight parts of PBAT, PLA, plasticized starch and the compatilizer are respectively as follows:

[0116]

[0117] The raw materials PLA, PBAT and plasticized starch are the same as those in the embodiment 1.

[0118] The compatilizer PBAT-g-EPB is the same as that in the embodiment 6.

[0119] The preparation method of the compatilized modified PBAT / PLA / plasticized starch composite material provided in the embodiment is as follows: the PBAT, PLA, plasticized starch and PBAT-g-EPB are added into a double-screw extruder according to weight parts, melt blending is carried out, the temperature of melt blending of the double-screw extruder is 150 DEG C, and the rotating speed is 50 r / min, so that the PBAT-g-EPB compatilized modified PBAT / PLA / plasticized starch composite material is prepared.

[0120] Example 10

[0121] The embodiment provides a compatilized modified PBAT / PLA / plasticized starch composite material, and raw materials for preparation are as follows: PBAT, PLA, plasticized starch and a compatilizer; the plasticized starch is oxamide modified starch; and the compatilizer is a 3,4-epoxy-1-butene graft of PBAT (PBAT-g-EPB).

[0122] In the raw materials for preparation, the weight parts of the PBAT, the PLA, the plasticized starch and the compatilizer are respectively as follows:

[0123] PBAT 70 parts

[0124] PLA 30 parts

[0125] Plasticized starch 20 parts

[0126] Compatilizer 0.01 part.

[0127] The raw materials of the PLA, the PBAT and the plasticized starch are the same as those in Example 1.

[0128] The compatilizer PBAT-g-EPB is the same as that in Example 6.

[0129] The compatilized modified PBAT / PLA / plasticized starch composite material provided in the embodiment has a preparation method that: the PBAT, the PLA, the plasticized starch and the PBAT-g-EPB are added into a double-screw extruder according to weight parts, melt blending is performed, the temperature of melt blending of the double-screw extruder is 150 DEG C, and the rotation speed is 50 r / min, so that the compatilized modified PBAT / PLA / plasticized starch composite material is prepared.

[0130] Comparative Example 1

[0131] The comparative example provides a PBAT / PLA / plasticized starch composite material, and raw materials for preparation are as follows: PBAT, PLA and plasticized starch; and the plasticized starch is oxamide modified starch.

[0132] In the raw materials for preparation, the weight parts of the PBAT, the PLA and the plasticized starch are respectively as follows:

[0133] PBAT 70 parts

[0134] PLA 30 parts

[0135] Plasticized starch 20 parts.

[0136] The raw materials of the PLA, the PBAT and the plasticized starch are the same as those in Example 1.

[0137] The PBAT / PLA / plasticized starch composite material provided by the present comparative example is prepared by adding PBAT, PLA and plasticized starch into a double screw extruder for melt blending, wherein the temperature of the melt blending of the double screw extruder is 150°C, and the rotating speed is 50 r / min.

[0138] Comparative Example 2

[0139] The present comparative example provides a compatibilized modified PBAT / PLA / plasticized starch composite material, and the raw materials are PBAT, PLA, plasticized starch and a compatibilizer.

[0140] In the raw materials, the weight fractions of PBAT, PLA, plasticized starch and the compatibilizer are respectively:

[0141]

[0142] The raw materials PLA and PBAT are the same as in Example 1.

[0143] The compatibilizer PBAT-g-EPB is the same as in Example 6.

[0144] The preparation method of the plasticized starch is as follows: starch and glycerol are weighed according to a mass ratio of 100:30, and then mixed uniformly in a high-speed mixer, wherein the temperature of the high-speed mixer is 80°C, and the rotating speed is 1200 r / min; then the mixture is sealed in a sealed bag and placed in a vacuum drying box at 80°C for 12 hours, and then melt blended in a double screw extruder, wherein the temperature of the double screw extruder is 150°C, and the rotating speed is 50 r / min, to obtain the plasticized starch.

[0145] The preparation method of the compatibilized modified PBAT / PLA / plasticized starch composite material provided by the present comparative example is as follows: PBAT, PLA, plasticized starch and PBAT-g-EPB are added into a double screw extruder for melt blending, wherein the temperature of the melt blending of the double screw extruder is 150°C, and the rotating speed is 50 r / min, to prepare the PBAT-g-EPB compatibilized modified PBAT / PLA / plasticized starch composite material.

[0146] Performance detection

[0147] The composite materials provided by the above examples and comparative examples are subjected to performance detection. The tests mainly include tensile strength and elastic modulus. The test method is as follows: a universal electronic testing machine (DF-101S, Gao Tie Testing Instrument Co., Ltd.) is used to test the tensile strength and elastic modulus according to the standard GB / T 1040.3-2006, and the tensile rate is 50 mm / min.

[0148] The test results are shown in Table 1.

[0149] Table 1

[0150]

[0151]

[0152] As can be seen from Table 1, the tensile strength and elastic modulus of the composite material prepared by the composite materials provided by Examples 1-10 are significantly improved compared with the comparative example 1 without adding the compatibilizer, and the composite material of the present application has excellent mechanical properties.

[0153] It can also be seen from the analysis of Examples 1-6 that, when preparing the compatibilizer PBAT-g-EPB, by increasing the ratio of the raw material 3,4-epoxy-1-butene and / or the initiator to the raw material PBAT, i.e. with the increase of the amount of the raw material 3,4-epoxy-1-butene and / or the initiator, the grafting rate of PBAT grafted with EPB can be increased, thereby improving the compatibility of the PBAT / PLA / plasticized starch composite system, and further improving the tensile strength and elastic modulus of the prepared composite material.

[0154] As can be seen from the comparison of Example 6 and Comparative Example 2, the tensile strength and elastic modulus of the prepared composite material are obviously better when using the oxamide modified starch as the plasticized starch than using the traditional glycerol modified starch.

[0155] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which do not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict, provided that the combinations do not conflict.

Claims

1. A compatibilized modified PBAT / PLA / plasticized starch composite material, characterized in that, The preparation raw materials include: PBAT, PLA, plasticized starch, and compatibilizer; the plasticized starch is oxamide modified starch; and the compatibilizer is 3,4-epoxy-1-butene graft of PBAT. In the preparation raw materials, the weight fractions of PBAT, PLA, plasticized starch, and compatibilizer are respectively: PBAT 50-90 parts PLA 10-50 parts Plasticized starch 10-40 parts Compatibilizer 0.01-2.0 parts.

2. The composite material of claim 1, wherein, The preparation method of the plasticized starch includes: mixing starch with oxamide, and then extruding by a twin-screw extruder to obtain the plasticized starch; wherein the mass ratio of the starch to the oxamide is 100: (15-35).

3. The composite material of claim 2, wherein, The mixing temperature of the starch and the oxamide is 70-90℃; the extrusion temperature of the twin-screw extruder is 140-160℃; and / or, After the mixing of the starch and the oxamide, the mixture is first dried, and then extruded by a twin-screw extruder; the drying temperature is 75-90℃, and the drying is performed under vacuum condition.

4. The composite material of claim 1, wherein, The preparation method of the 3,4-epoxy-1-butene graft of PBAT includes: melt blending PBAT with 3,4-epoxy-1-butene and initiator to prepare the 3,4-epoxy-1-butene graft of PBAT; Wherein, the mass ratio of the PBAT to the 3,4-epoxy-1-butene is 100: (0.1-1.5) in feeding; and / or, The mass ratio of the PBAT to the initiator is 100: (1.2-3.0) in feeding.

5. The composite material of claim 4, wherein, The initiator is dicumyl peroxide and / or dibenzoyl peroxide.

6. The composite material of claim 4, wherein, The melt blending temperature is 130-170℃.

7. The composite material of claim 1, wherein, The number average molecular weight of the PBAT is 40000-60000; and / or, the number average molecular weight of the PLA is 50000-80000.

8. A method of producing the composite material according to any one of claims 1 to 7, characterized in that, The method includes the step of: melt blending PBAT, PLA, plasticized starch, and compatibilizer to obtain a compatibilized and modified PBAT / PLA / plasticized starch composite material; wherein the melt blending temperature is 140-160℃.

9. Use of the composite material of any one of claims 1-7 in a preservative film, mulch film, or packaging film.

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