Compatibilization modified PBAT / PLA / plasticized starch composite material and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly discloses a compatibilization modified PBAT / PLA / plasticized starch composite material and a preparation method thereof. The compatibilization modified PBAT / PLA / plasticized starch composite material provided by the invention is prepared from the following raw materials: PBAT, PLA, plasticized starch and a compatibilizer. The plasticized starch is starch modified by oxamide; the compatibilizer is a 3, 4-epoxy-1-butene graft of PBAT (poly (butylene adipate-co-terephthalate)). The compatibilization modified PBAT / PLA / plasticized starch composite material provided by the invention has high tensile strength and elasticity modulus, and excellent mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a volume-enhanced modified PBAT / PLA / plasticized starch composite material, and also relates to a preparation method thereof. Background Art

[0002] Polybutylene terephthalate (PBAT) is a completely biodegradable polymer material with butylene terephthalate segments (BT) and butylene adipate segments (BA) as random repeating units. PBAT has the advantages of high elongation at break, good processability, good toughness, etc., but the melt strength, elastic modulus and tensile strength of PBAT are poor, which limits its application. Polylactic acid (PLA) has sufficient strength and rigidity. By adding PLA to PABT, the mechanical properties such as strength and rigidity of PBAT can be improved. Starch is low in price and can be biodegraded, so blending starch with PBAT and PLA can reduce the production cost of the material. Blending PBAT, PLA and starch can give full play to their respective advantages.

[0003] However, there are still problems in the preparation of PBAT, PLA and starch composite materials. For example, the decomposition temperature of starch is much lower than the melting temperature. When heated, the starch decomposes before reaching the melting point of starch, and the processing performance is poor. Therefore, it is necessary to plasticize the starch to make plasticized starch, so that the starch crystallization performance decreases, the melting temperature decreases, and the starch is melted before decomposition, so that the starch can be processed and formed. In addition, starch contains a large number of hydroxyl groups and is hydrophilic, while PLA and PBAT have only a small amount of hydroxyl groups, and PLA and PBAT are hydrophobic. Therefore, the compatibility of starch with PLA and PBAT is poor, and the solubility parameters of PLA and PBAT differ by more than 10, and the compatibility of PLA and PBAT is also poor. How to improve the compatibility of PBAT, PLA and starch to give full play to the excellent performance of PLA, PBAT and starch is still a problem that needs to be solved now.

[0004] Based on the above problems, the present invention intends to provide a PBAT / PLA / plasticized starch composite material with a capacity increase and modification to improve the performance of the PBAT / PLA / plasticized starch composite material. Summary of the invention

[0005] The object of the present invention is to provide a compatibilized PBAT / PLA / plasticized starch composite material, and also provides a preparation method thereof.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions.

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

[0008] Wherein, the plasticized starch is starch modified with oxalamide;

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

[0010]

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

[0012] As an embodiment of the present invention, in the preparation raw materials, the weight proportions of PBAT, PLA, plasticized starch, and compatibilizer are respectively:

[0013] PBAT 50-90 copies

[0014] PLA 10-50 parts

[0015] 10-40 parts of plasticized starch

[0016] Compatibilizer 0.01-2.0 parts.

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

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

[0019] As an embodiment of the present invention, the preparation method of the plasticized starch comprises: mixing starch with oxamide, and then extruding with a twin-screw extruder to obtain the plasticized starch. The starch and the oxamide are mixed in a mass ratio of 100:(15-35).

[0020] As an embodiment of the present invention, during the preparation of plasticized starch, the mixing temperature of the starch and the oxamide is 70-90°C; and the extrusion temperature of the twin-screw extruder is 140-160°C.

[0021] As an embodiment of the present invention, after the starch and oxalamide are mixed, they are first dried and then extruded using a twin-screw extruder. The drying temperature is 75-90° C. and the drying is performed under vacuum conditions.

[0022] As an embodiment of the present invention, the preparation method of the 3,4-epoxy-1-butene graft of PBAT includes: melt blending PBAT, 3,4-epoxy-1-butene and an initiator to obtain the 3,4-epoxy-1-butene graft of PBAT. The PBAT and the 3,4-epoxy-1-butene are fed in a mass ratio of 100: (0.1-1.5). The PBAT and the initiator are fed in a mass ratio of 100: (1.2-3.0).

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

[0024] As an embodiment of the present invention, during the preparation of the 3,4-epoxy-1-butene graft of PBAT, the temperature of the melt blending is 130-170°C.

[0025] As an embodiment of the present invention, the number average molecular weight of the PBAT is 40,000-60,000.

[0026] As an embodiment of the present invention, the number average molecular weight of the PLA is 50,000-80,000.

[0027] In a second aspect, the present invention provides a method for preparing a compatibilized PBAT / PLA / plasticized starch composite material, comprising the steps of: melt blending PBAT, PLA, plasticized starch, and a compatibilizer to obtain a compatibilized PBAT / PLA / plasticized starch composite material, wherein the melt blending temperature is 140-160°C.

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

[0029] The present invention provides a volume-enhanced modified PBAT / PLA / plasticized starch composite material, wherein a PBAT-g-EPB graft prepared by a melting method is used as a volume-enhancing agent, and starch modified by oxalamide is used as a plasticized starch, which is melt-blended with PBAT and PLA to prepare a volume-enhanced modified PBAT / PLA / plasticized starch composite material.

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

[0031] The technical solution of the present invention is further described in detail below. It should be understood by those skilled in the art that the specific implementation is only to help understand the present invention and should not be regarded as a specific limitation of the present invention.

[0032] It should be noted that, unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art. Unless otherwise specified, the raw materials used in the present invention are all commercially available conventional commodities and can be purchased.

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

[0034] Preferably, the volume-enhanced modified PBAT / PLA / plasticized starch composite material, in the preparation raw materials, the weight proportions of PBAT, PLA, plasticized starch, and volume-enhancing agent are respectively:

[0035] PBAT 50-90 copies

[0036] PLA 10-50 parts

[0037] 10-40 parts of plasticized starch

[0038] Compatibilizer 0.01-2.0 parts.

[0039] In the present invention, the preparation method of plasticized starch comprises: mixing starch with oxamide, and then extruding with a twin-screw extruder to obtain the plasticized starch. The starch and the oxamide are mixed in a mass ratio of 100:(15-35). Specifically, the starch and the oxamide can be mixed in 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 invention, the mixing temperature of starch and oxalamide is 70-90° C. Specifically, the mixing temperature may be 70° C., 75° C., 80° C., 85° C., 90° C. or any other temperature within the range of 70-90° C.

[0041] In the present invention, during the preparation of plasticized starch, the extrusion temperature of the twin-screw extruder is 140-160° C. Specifically, the extrusion temperature may be 140° C., 145° C., 150° C., 155° C., 160° C. or any other temperature within the range of 140-160° C.

[0042] In the present invention, after starch and oxalamide are mixed, they are first dried and then extruded by a twin-screw extruder. The drying temperature is 75-90°C, and the drying is carried out under vacuum conditions for 8-12 hours. Specifically, the drying temperature can be 75°C, 80°C, 85°C, 90°C or any other temperature within the range of 75-90°C.

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

[0044] Among them, PBAT and 3,4-epoxy-1-butene are fed in a mass ratio of 100:(0.1-1.5). Specifically, PBAT and 3,4-epoxy-1-butene are fed in a mass ratio of 100:0.1, 100:0.5, 100:0.7, 100:1.0, 100:1.2, 100:1.4, 100:1.5 or any other ratio within the range of 100:(0.1-1.5).

[0045] Wherein, PBAT and initiator are fed in a mass ratio of 100:(1.2-3.0). Specifically, PBAT and initiator are fed in a mass ratio of 100:1.2, 100:1.4, 100:1.8, 100:2.0, 100:2.5, 100:2.8, 100:3.0 or any other ratio within the range of 100:(1.2-3.0).

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

[0047] In the present invention, when preparing 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB), the temperature of melt blending is 130-170° C. Specifically, the temperature of melt blending can be 130° C., 140° C., 150° C., 160° C., 170° C. or any other temperature within the range of 130-170° C.

[0048] In the present invention, the number average molecular weight of the PBAT used is 40,000-60,000.

[0049] In the present invention, the number average molecular weight of the PLA used is 50,000-80,000.

[0050] The preparation method of the composite material provided by the present invention comprises the steps of: melt blending PBAT, PLA, plasticized starch, and a compatibilizer to obtain a compatibilized modified PBAT / PLA / plasticized starch composite material. The melt blending temperature is 140-160°C. Specifically, the melt blending temperature can be 140°C, 150°C, 160°C, or any other temperature within the range of 140-160°C.

[0051] The following is a detailed explanation through specific examples.

[0052] Example 1

[0053] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

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

[0055]

[0056] The number average molecular weight of the raw material PLA is 50,000.

[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 50,000.

[0058] The preparation method of plasticized starch is as follows: starch and oxalamide are weighed at a mass ratio of 100:30, and then added into a high-speed mixer and mixed evenly. The temperature of the high-speed mixer is 80°C and the rotation speed is 1200r / min; then sealed with a sealing bag, placed in a vacuum drying oven at 80°C for 12 hours, and then added into a twin-screw extruder for melt blending. The temperature of the twin-screw extruder is 150°C and the rotation speed is 50r / min to obtain plasticized starch.

[0059] The preparation method of the compatibilizer PBAT-g-EPB is as follows: weigh 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 diisopropylbenzene peroxide (DCP); add PBAT, 3,4-epoxy-1-butene, and DCP into a twin-screw extruder for melt blending at a temperature of 150°C and a speed of 50r / min for the twin-screw extruder to obtain PBAT-g-EPB with a grafting rate of 0.53. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is:

[0060]

[0061] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0062] Example 2

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

[0064] In the preparation of raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0065]

[0066] The raw materials PLA, PBAT and plasticized starch are the same as those in Example 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 dibenzoyl peroxide (BPO) are weighed; PBAT, 3,4-epoxy-1-butene, and BPO are added to a twin-screw extruder for melt blending, the melt blending temperature is 150° C., the speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is obtained by extrusion, and the grafting rate is 0.61. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Example 1.

[0068] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0069] Example 3

[0070] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

[0071] In the preparation of raw materials, the weight proportions 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 Example 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 2.8 parts by weight of initiator DCP are weighed; PBAT, 3,4-epoxy-1-butene, and DCP are added to a twin-screw extruder for melt blending, the melt blending temperature is 150° C., the speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is obtained by extrusion, and the grafting rate is 0.78. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Example 1.

[0075] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0076] Example 4

[0077] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

[0078] In the preparation of raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0079]

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

[0081] 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 2.8 parts by weight of initiator BPO are weighed; PBAT, 3,4-epoxy-1-butene, and BPO are added to a twin-screw extruder for melt blending, the melt blending temperature is 150° C., the speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is obtained by extrusion, and the grafting rate is 0.84. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Example 1.

[0082] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0083] Example 5

[0084] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

[0085] In the preparation of raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0086]

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

[0088] 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 DCP are weighed; PBAT, 3,4-epoxy-1-butene, and DCP are added to a twin-screw extruder for melt blending, the melt blending temperature is 150° C., the speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is obtained by extrusion, and the grafting rate is 1.15. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Example 1.

[0089] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0090] Example 6

[0091] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

[0092] In the preparation of raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0093]

[0094]

[0095] The raw materials PLA, PBAT and plasticized starch are the same as those in Example 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; PBAT, 3,4-epoxy-1-butene, and BPO are added to a twin-screw extruder for melt blending, the melt blending temperature is 150° C., the speed of the twin-screw extruder is 50 r / min, and PBAT-g-EPB is obtained by extrusion, and the grafting rate is 1.19. The reaction formula involved in the preparation of the compatibilizer PBAT-g-EPB is the same as that in Example 1.

[0097] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0098] Example 7

[0099] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

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

[0101]

[0102]

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

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

[0105] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0106] Example 8

[0107] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

[0108] In the preparation of raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0109]

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

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

[0112] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0113] Example 9

[0114] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

[0115] In the preparation of raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0116]

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

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

[0119] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0120] Example 10

[0121] The present embodiment provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

[0122] In the preparation of raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively:

[0123] PBAT 70 copies

[0124] PLA 30 parts

[0125] 20 parts of plasticized starch

[0126] 0.01 part of compatibilizer.

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

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

[0129] The prepared PBAT / PLA / plasticized starch composite material provided in this embodiment is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT / PLA / plasticized starch composite material with PBAT-g-EPB volume-modified.

[0130] Comparative Example 1

[0131] This comparative example provides a PBAT / PLA / plasticized starch composite material, and the raw materials for preparation are: PBAT, PLA, and plasticized starch; the plasticized starch is starch modified with oxalamide.

[0132] In the preparation of raw materials, the weight proportions of PBAT, PLA and plasticized starch are respectively:

[0133] PBAT 70 copies

[0134] PLA 30 parts

[0135] 20 parts of plasticized starch.

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

[0137] The PBAT / PLA / plasticized starch composite material provided in this comparative example is prepared by adding PBAT, PLA, and plasticized starch into a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the rotation speed is 50 r / min to prepare the PBAT / PLA / plasticized starch composite material.

[0138] Comparative Example 2

[0139] This comparative example provides a compatibilized modified PBAT / PLA / plasticized starch composite material, the raw materials for preparation are: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is glycerol-modified starch; and the compatibilizer is 3,4-epoxy-1-butene grafted product of PBAT (PBAT-g-EPB).

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

[0141]

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

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

[0144] The preparation method of plasticized starch is as follows: starch and glycerol are weighed according to a mass ratio of starch to glycerol of 100:30, and then added into a high-speed mixer and mixed evenly, the temperature of the high-speed mixer is 80°C, and the rotation speed is 1200r / min; then sealed with a sealing bag, placed in a vacuum drying oven at 80°C for 12 hours, and then added into a twin-screw extruder for melt blending, the temperature of the twin-screw extruder is 150°C, and the rotation speed is 50r / min, to obtain plasticized starch.

[0145] The preparation method of the volume-modified PBAT / PLA / plasticized starch composite material provided in this comparative example is as follows: PBAT, PLA, plasticized starch, and PBAT-g-EPB are added to a twin-screw extruder according to weight proportions for melt blending. The melt blending temperature of the twin-screw extruder is 150° C. and the speed is 50 r / min to prepare a PBAT-g-EPB volume-modified PBAT / PLA / plasticized starch composite material.

[0146] Performance Testing

[0147] The composite materials provided in the above embodiments and comparative examples were tested for performance. The tensile strength and elastic modulus were mainly tested. The test method is as follows: a universal electronic testing machine (DF-101S, High Speed ​​Rail Testing Instrument Co., Ltd.) was used to test the tensile strength and elastic modulus according to GB / T 1040.3-2006 standard, and the tensile rate was 50 mm / min.

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

[0149] Table 1

[0150]

[0151]

[0152] It can be seen from Table 1 that the composite materials provided by Examples 1-10 of the present invention have significantly improved tensile strength and elastic modulus compared to Comparative Example 1 in which no compatibilizer is added, and the composite materials of the present invention have excellent mechanical properties.

[0153] Analysis of Examples 1-6 also shows 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, that is, as the amount of the raw material 3,4-epoxy-1-butene and / or the initiator increases, the grafting rate of PBAT grafted to EPB can be increased, thereby improving the compatibility of the PBAT / PLA / plasticized starch composite system, thereby improving the tensile strength and elastic modulus of the obtained composite material.

[0154] Comparison of Example 6 with Comparative Example 2 shows that the tensile strength and elastic modulus of the composite material prepared by using plasticized starch as oxalamide-modified starch are significantly better than those of the traditional glycerol-modified starch.

[0155] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A compatibilized PBAT / PLA / plasticized starch composite material, characterized in that: The preparation raw materials include: PBAT, PLA, plasticized starch, and a compatibilizer; the plasticized starch is oxalamide-modified starch; and the compatibilizer is a 3,4-epoxy-1-butene graft of PBAT.

2. The composite material according to claim 1, characterized in that In the preparation raw materials, the weight proportions of PBAT, PLA, plasticized starch and compatibilizer are respectively: PBAT 50-90 copies PLA10-50 parts 10-40 parts of plasticized starch Compatibilizer 0.01-2.0 parts.

3. The composite material according to claim 1 or 2, characterized in that: The preparation method of the plasticized starch comprises: mixing starch with oxamide, and then extruding with a twin-screw extruder to obtain the plasticized starch; wherein the starch and the oxamide are mixed in a mass ratio of 100:(15-35).

4. The composite material according to claim 3, characterized in that The mixing temperature of the starch and the oxalamide is 70-90° C.; the extrusion temperature of the twin-screw extruder is 140-160° C.; and / or, After the starch and oxalamide are mixed, they are first dried and then extruded by a twin-screw extruder. The drying temperature is 75-90° C. and the drying is performed under vacuum conditions.

5. The composite material according to claim 1, characterized in that The preparation method of the 3,4-epoxy-1-butene graft of PBAT comprises: melt-blending PBAT, 3,4-epoxy-1-butene and an initiator to obtain the 3,4-epoxy-1-butene graft of PBAT; Wherein, the PBAT and the 3,4-epoxy-1-butene are fed in a mass ratio of 100:(0.1-1.5); and / or, The PBAT and the initiator are added in a mass ratio of 100:(1.2-3.0).

6. The composite material according to claim 5, characterized in that The initiator is dicumyl peroxide and / or dibenzoyl peroxide.

7. The composite material according to claim 5, characterized in that The temperature of the melt blending is 130-170°C.

8. The composite material according to claim 1, characterized in that The number average molecular weight of the PBAT is 40,000-60,000; and / or the number average molecular weight of the PLA is 50,000-80,000.

9. A method for preparing the composite material according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: melt-blending PBAT, PLA, plasticized starch and a compatibilizer to obtain a compatibilized modified PBAT / PLA / plasticized starch composite material; wherein the melt-blending temperature is 140-160°C.

10. Use of the composite material according to any one of claims 1 to 8 in fresh-keeping film, ground film and packaging film.

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