CN113736226A

CN113736226A - Degradable PBAT composite film and preparation method thereof

Info

Publication number: CN113736226A
Application number: CN202111024194.5A
Authority: CN
Inventors: 詹佐民; 陈连清; 祁先勇; 李保印; 吴俊�; 邵成立; 王倩倩; 黄建; 李熠宇; 欧阳洋子; 袁天楠; 刘雪婷
Original assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd
Priority date: 2021-09-02
Filing date: 2021-09-02
Publication date: 2021-12-03

Abstract

The invention discloses a degradable PBAT composite film and a preparation method thereof. In the invention, the metal organic framework is modified by adopting the coupling agent, so that the PBAT composite film has the functions of adsorbing small molecules and removing odor, and can be uniformly dispersed in PBAT together with the filler, the prepared PBAT composite film is easy to process, uniformly dispersed, low in odor and high in performance, and can be used in thin film packaging materials requiring low odor, such as commercial super vest bags, food packaging bags and the like.

Description

Degradable PBAT composite film and preparation method thereof

Technical Field

The invention belongs to the field of degradable materials, and particularly relates to a low-odor biodegradable PBAT composite film and a preparation method thereof.

Background

Along with the development of national economy and the rise of internet economy, the consumption of plastic products is continuously increased, and the use amount of plastic packages, such as bubble films, bubble bags and the like, in the express industry is synchronously increased. Although the waste of plastics is reduced by adopting the modes of recycling, crushing and reusing at present, thereby alleviating white pollution, the method is not a permanent cure. With the implementation of plastic forbidden commands, industries such as express delivery and the like also begin to seek alternative schemes in advance, and the degradable resin attracts the attention of a plurality of researchers and enterprises due to the degradation characteristic.

Polybutylene terephthalate/adipate (PBAT) is a fully biodegradable polyester material that can be metabolically decomposed by microorganisms, ultimately to carbon dioxide and water. The PBAT has better ductility and elongation at break, and has certain strength after film forming, but because the PBAT increases the shearing strength in processing when the mineral powder is filled, small molecules contained in the PBAT and small molecules generated by decomposition are easy to disperse, the produced film bag has large smell, bad use experience is brought to users, and further development and application of the film bag are influenced. How to create a degradable PBAT composite film with low smell and a preparation method thereof have very important significance.

Disclosure of Invention

The invention aims to provide a degradable PBAT composite film, which is prepared by modifying a metal organic framework to prepare a metal organic framework-coupling agent reactant, so that the metal organic framework can be uniformly dispersed in the composite film, crystal points are not generated in the processing process of preparing a film bag, and meanwhile, talcum powder is assisted to disperse, and the prepared PBAT composite film is low in smell.

In order to achieve the purpose, the invention adopts the following technical scheme:

a degradable PBAT composite film, the PBAT composite film comprising the following components:

s1, PBAT, 60% to 85%, preferably 65% to 80%;

s2, PLA, 5% -30%, preferably 8% -20%;

s3, 5-30% of talcum powder, and preferably 8-20%;

s4, slipping agent, 0.05% -2%, preferably 0.1% -5%;

s5, a chain extender, 0.05% -2%, preferably 0.1% -0.6%;

s6, a modified metal organic framework, 0.05% -2%, preferably 0.1% -1%;

based on the total mass of all the components as 100 percent.

The modified metal organic framework is prepared from the following components:

s6-1, a metal organic framework, 45% -75%, preferably 50% -65%;

s6-2, coupling agent, 25% -55%, preferably 35% -50%;

wherein the metal organic framework is prepared by reacting zirconium salt and 2-amino terephthalic acid.

Preferably, the zirconium salt is zirconium chloride.

The metal organic framework prepared by the invention has good odor adsorption effect on the PBAT composite film material, and the prepared material has low odor grade and can meet the requirement of food grade. However, in the process of research on the PBAT composite film, it is found that if the metal organic framework is directly added to the modified material, crystal points are formed on the film, and agglomeration is generated, so that the effect of adsorbing small molecules cannot be achieved. But the invention firstly compounds the metal organic framework and the coupling agent to obtain the modified metal organic framework, and then blends the modified metal organic framework and the PBAT and other raw materials, and the compatibility of the raw materials is better by adopting the method, so that the uneven dispersion of the metal organic framework in the processing process is avoided, and the modified metal organic framework can better adsorb small molecules, thereby leading the prepared modified PBAT composite film to have lower odor.

In the invention, the PBAT can be PBAT prepared by a direct polycondensation method or PBAT prepared by a two-step chain extension method or a mixture thereof, and the PBAT prepared by the two-step chain extension method is preferred.

In the invention, the PLA (polylactic acid) is PLA prepared by a ring-opening polymerization method or PLA prepared by a direct polycondensation method or a mixture thereof, preferably PLA prepared by a ring-opening polymerization method; preferably, the melt index of the PLA is from 3 to 20g/10min (190 ℃, 2.16kg), preferably from 3 to 10g/10min (190 ℃, 2.16 kg).

In the invention, the fineness of the talcum powder is 1000-10000 meshes, and the preferable fineness is 3000-6000 meshes.

In the invention, the slipping agent is one or more of stearic acid amide, erucamide and oleic acid amide, preferably erucamide.

In the invention, the chain extender is one or more of glyceride multipolymer, isocyanate and peroxide, preferably glyceride multipolymer, such as chain extender HDI, ADR4400 and STJ-20.

In the invention, the coupling agent is one or more of silane coupling agent, titanate coupling agent and borate coupling agent, and preferably silane coupling agent. Such as KH-560, KR-12, LD-100P.

The preparation method of the modified metal organic framework comprises the following steps:

A. mixing zirconium chloride and 2-amino terephthalic acid, adding the mixture into a mixed solvent, transferring the mixture into a high-pressure reaction kettle to obtain yellow jelly, washing and drying to prepare a metal organic framework;

B. and mixing the metal organic framework, a coupling agent and N' N dimethylformamide, heating and refluxing, and then carrying out rotary evaporation to obtain a yellow solid, washing and drying the yellow solid, thus preparing the modified metal organic framework.

In the invention, the reaction temperature in the step A is 100-150 ℃, the heating time is 24-72h, preferably 110-140 ℃, and 36-60 h; reaction pressure: gauge pressure is 5-20MPa, preferably 10-15 MPa.

In the invention, the mixed solvent in the step A is N 'N dimethylformamide and deionized water, and the mass ratio of the N' N dimethylformamide to the deionized water is 5: 1-25: 1, preferably 10: 1-20: 1.

the amount of the mixed solvent added is 3 to 15 times, preferably 5 to 10 times, the mass of zirconium chloride.

In the invention, the amount of the 2-amino terephthalic acid is 1 to 5 times, preferably 1 to 2 times of the mass of the zirconium chloride;

in the present invention, step a washes the metal organic framework with N' N dimethylformamide and methanol.

In the invention, the heating temperature in the step B is 100-150 ℃, the heating time is 1-24h, preferably the heating temperature is 110-140 ℃, and the heating time is 5-12 h.

In the invention, the mass ratio of the metal-organic framework to the coupling agent in the step B is 1:1-1:4, preferably 1: 1.5-1: 2.5.

in the invention, the product can be washed by N' N dimethylformamide and trichloromethane in the step B.

Another object of the present invention is to provide a method for preparing the degradable PBAT composite film.

A method for preparing the degradable PBAT composite film, the method comprising the steps of:

C. mixing a small amount of talcum powder, a slipping agent, a chain extender and a modified metal organic framework, adding the mixture, PBAT and PLA into a main feeding port of a double-screw extruder, feeding the rest talcum powder from a side feeding port, then carrying out melt extrusion, cooling, granulating and drying to obtain the PBAT modified alloy.

D. Adding the PBAT modified alloy into a film blowing machine, and further processing to obtain the PBAT composite film.

In the invention, a high-speed mixer is adopted for mixing in the step C, and the rotating speed is 20-100 rpm, preferably 30-80 rpm; the mixing time is 3-10 min, preferably 5-7 min; the screw temperature of the plasticizing section of the double-screw extruder is 150-210 ℃, and preferably 160-200 ℃; the rotation speed is 100-800rpm, preferably 200-500 rpm.

In the invention, the screw temperature of the film blowing machine is 130-180 ℃, preferably 140-160 ℃; the rotation speed is 5-30Hz, preferably 10-20 Hz.

Compared with the prior art, the invention has the following technical advantages:

(1) the PBAT composite film is modified by adding the metal organic framework, so that the smell of the PBAT composite film is greatly improved, almost no smell is generated, the performances of the PBAT composite film such as mechanics, heat seal and the like are not reduced, and the product is more friendly to consumers.

(2) Compared with the traditional porous adsorbent, the metal organic framework has higher porosity and larger specific surface area, and the adsorption capacity is greatly improved, so that the smell of the PBAT composite film is reduced.

(3) Compared with the method of directly adding the metal organic framework, the method firstly modifies the metal organic framework, increases the compatibility of the metal organic framework and the matrix, and avoids uneven dispersion of the metal organic framework in the processing process, so that the smell of the prepared modified PBAT composite film achieves a better effect.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to be illustrative of the invention and are not to be construed as limiting the scope of the invention.

In each of the examples and comparative examples, the main raw material sources were as follows:

raw material	Manufacturer of the product
		PBAT(801T)	XINJIANG BLUE RIDGE TUNHE POLYESTER Co.,Ltd.
PLA(LX575)	Doudaro Bien polylactic acid Co Ltd
		AH51210L	LIAONING AIHAI TALC Co.,Ltd.
Chain extender ADR4468	BASF SE
		Erucamide	Dahlia chemical (Shanghai) Co Ltd
XW-1200	Qingdao Century Zhuoxin New Material Technology Co., Ltd.
		KH-560	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
Zirconium chloride	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
		2-amino terephthalic acid	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
N' N dimethylformamide	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
		Methanol	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.
Trichloromethane	SHANGHAI ALADDIN BIOCHEMICAL TECHNOLOGY Co.,Ltd.

Other raw materials and reagents were obtained from commercial sources unless otherwise specified.

In each of the examples and comparative examples, the odor rating of the PBAT composite film was tested according to standard GB/T35773-2017 with a sample size of 600cm²The test condition is that the glass is placed for 24 hours at 23 ℃ in the dark; samples were rated from low to high odor, 0-4.

The processing equipment is as follows: a twin-screw extruder, koilong, model ZSK 26Mc 18, length-diameter ratio of 52, screw diameter of 26 cm; a film blowing machine, a model SCM 25, a length-diameter ratio of 30 and a screw diameter of 25 cm.

The test equipment used was: german Leifheit odor bottle, 1L specification.

Example 1

(1) Preparation of Metal Organic Frameworks (MOFs)

100g of zirconium chloride and 100g of 2-aminoterephthalic acid are weighed and added into a flask, 300mL of N' N dimethylformamide is added, 40mL of deionized water is added, the mixture is stirred fully and then transferred into a high-pressure reaction kettle with a polytetrafluoroethylene lining, and the reaction is carried out for 36 hours at 150 ℃. After the reaction kettle is naturally cooled, 300mL of N' N dimethylformamide is added into the product, ultrasonic washing is carried out for 10 minutes, and the product is transferred to a rotary evaporator and evaporated to dryness at 80 ℃. The obtained yellow powder was washed three times with methanol in a suction filtration apparatus and then dried in an oven at 100 ℃.

(2) Preparation of modified Metal organic frameworks (M-MOF)

100g of the metal organic framework prepared in step (1) and 150g of KH-560 were weighed into a three-necked flask, 300mL of N' N dimethylformamide was added, and after stirring sufficiently, the mixture was reacted in an oil bath at 150 ℃ for 8 hours. And after natural cooling, performing rotary evaporation, cleaning the obtained yellow powder with N' N dimethylformamide in a suction filtration device for three times, then cleaning with trichloromethane for three times, and transferring to a 100 ℃ oven for drying.

(3) The PBAT composite film is prepared by taking the modified metal organic framework and the formula components in the table 1 as raw materials and referring to the raw material dosage in the table 1 according to the following method:

a) firstly, respectively drying PBAT and PLA pure materials in a dehumidification drying oven for 4 hours at the temperature of 80 DEG C

b) Mixing talcum powder, slipping agent, chain extender and the modified metal organic framework mixing equipment at the speed of 90rpm for 7 min. Then adding the mixture, PBAT and PLA into the main feeding port of the double-screw extruder, feeding the rest talcum powder from the side feeding port, and then melting and extruding.

The extrusion conditions were: the rotating speed of the screw is 300rpm, and the temperature of the screw is set from the feed opening to the machine head in a segmented mode as follows: at 100 deg.C,

160℃、170℃、170℃、170℃、180℃、180℃、180℃、190℃、190℃、190℃。

c) And cooling the extruded material in a water tank of an extruder, pelletizing, and drying in a vacuum oven at 90 ℃ for 4 hours to obtain the modified PBAT alloy.

Example 2

The modified metal organic framework (M-MOF) prepared in example 1 was used as a raw material, and the PBAT composite film was prepared according to the method in example 1, except that the ratio of the added modified metal organic framework was different, and the specific formulation is shown in table 1.

Example 3

Example 4

Example 5

Example 6

A modified metal organic framework (M-MOF) was prepared using the method of example 1, except that 50g of zirconium chloride and 100g of 2-aminoterephthalic acid were added in step (1), and the ratio of 1: 2.5 of the weight ratio of the metal organic framework and the coupling agent KR-12, the rest of the method is the same as the example 1, and the PBAT composite film formula is shown in the table 1. Example 7

The PBAT composite film is prepared by taking the modified metal organic framework (M-MOF) prepared in example 1 as a raw material and adopting the method in example 1, and the difference is that the production process is different, and the extrusion conditions of a double-screw extruder are as follows: the rotating speed of the screw is 300rpm, and the temperature of the screw is set from the feed opening to the machine head in a segmented mode as follows: 180 ℃, 190 ℃.

Comparative example 1

The preparation method of the PBAT composite film according to the embodiment 1 is characterized in that the Metal Organic Framework (MOF) is prepared by using the Metal Organic Framework (MOF) as a raw material without modifying the metal organic framework with a coupling agent in the step (1) in the embodiment 1, and the difference is that the metal organic framework in the step (1) is directly added to the preparation of the PBAT composite film without modifying the metal organic framework with the coupling agent.

Comparative example 2

A PBAT composite film was prepared by the method of example 1 using a commercially available adsorbent (XW-1200) as a raw material without modification.

Comparative example 3

A PBAT composite film was prepared as in example 1 without addition of an adsorbent, except that no adsorbent was added.

Comparative example 4

A Metal Organic Framework (MOF) was prepared in the same manner as in step (1) of example 1, and then a PBAT composite film was prepared in the same manner as in example 1, except that the metal organic framework prepared in step (1) was not modified by a coupling agent, and the coupling agent was added in the same ratio when the PBAT composite film was prepared, and the specific formulation is as shown in table 1.

The modified PBAT alloys obtained in examples 1-7 and comparative examples 1-4 were blown into films in an extrusion film blowing machine at a screw temperature of 150 ℃, 170 ℃, 175 ℃ and a screw rotation speed of 12Hz, and the films were extruded into films with a thickness of 25 μm, and the results of the odor level tests of the films are shown in Table 2.

TABLE 1 raw materials and amounts (%)

TABLE 2 results of odor rating tests for examples 1-7 and comparative examples 1-4(D1-D4)

TABLE 3 film property results for examples 1-7 and comparative examples 1-3(D1-D3)

It can be seen from comparative examples 1-4 and example 4 that, compared with the traditional method of directly adding MOF, the PBAT composite film prepared by adding modified MOF increases the compatibility of itself with the matrix, and also increases the dispersion of talcum powder in the film, thereby avoiding aggregation caused by uneven dispersion of MOF in the processing process, and further achieving the effect of enhancing the tensile strength and tear strength of the film. In addition, the amino hydrogen introduced by the MOF obviously reduces the resistivity of the film, thereby meeting the antistatic requirement (less than 10)⁹Ω). Finally, the prepared film obviously reduces the odor of the film due to the excellent adsorption capacity of the MOF, and the product is more friendly to consumers.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and additions can be made without departing from the method of the present invention, and these modifications and additions should also be regarded as the protection scope of the present invention.

Claims

1. A degradable PBAT composite film, comprising the following components:

s1, PBAT, 60% to 85%, preferably 65% to 80%;

s2, PLA, 5% -30%, preferably 8% -20%;

s3, 5-30% of talcum powder, and preferably 8-20%;

s4, slipping agent, 0.05% -2%, preferably 0.1% -5%;

s5, a chain extender, 0.05% -2%, preferably 0.1% -0.6%;

s6, a modified metal organic framework, 0.05% -2%, preferably 0.1% -1%;

based on the total mass of all the components as 100 percent.

2. The composite film according to claim 1, wherein the modified metal organic framework is prepared from the following components:

s6-1, a metal organic framework, 45% -75%, preferably 50% -65%;

s6-2, coupling agent, 25% -55%, preferably 35% -50%;

preferably, the metal organic framework is prepared by reacting a zirconium salt and 2-amino terephthalic acid.

3. Composite film according to claim 1 or 2, wherein the PLA (polylactic acid) is a PLA prepared by a ring-opening polymerization process or a PLA prepared by a direct polycondensation process or a mixture thereof, preferably a PLA prepared by a ring-opening polymerization process; preferably, the melt index of the PLA is from 3 to 20g/10min (190 ℃, 2.16kg), preferably from 3 to 10g/10min (190 ℃, 2.16 kg).

4. The composite film according to any one of claims 1 to 3, wherein the talc has a fineness of 1000 mesh to 10000 mesh, preferably 3000-6000 mesh;

preferably, the slipping agent is one or more of stearic acid amide, erucamide and oleic acid amide, preferably erucamide;

preferably, the chain extender is one or more of a glyceride multipolymer, an isocyanate and a peroxide, preferably a glyceride multipolymer;

preferably, the coupling agent is one or more of a silane coupling agent, a titanate coupling agent and a borate coupling agent, preferably a silane coupling agent.

5. The composite film according to any one of claims 1 to 4, wherein the method for preparing the modified metal organic framework comprises the following steps:

A. mixing zirconium chloride and 2-amino terephthalic acid, adding the mixture into a mixed solvent, transferring the mixture into a high-pressure reaction kettle to obtain yellow jelly, washing and drying the yellow jelly to prepare a metal organic framework;

6. The composite film according to claim 5, wherein the reaction temperature of step A is 100-150 ℃, the heating time is 24-72h, preferably 110-140 ℃, 36-60 h; reaction pressure: gauge pressure is 5-20MPa, preferably 10-15 MPa;

preferably, the mixed solvent of the step A is N 'N dimethylformamide and deionized water, and the mass ratio of the N' N dimethylformamide to the deionized water is 5: 1-25: 1, preferably 10: 1-20: 1;

preferably, the addition amount of the mixed solvent is 3 to 15 times, preferably 5 to 10 times of the mass of the zirconium chloride;

preferably, the 2-aminoterephthalic acid is used in an amount of 1 to 5 times, preferably 1 to 2 times, the mass of zirconium chloride;

preferably, step a washes the metal organic framework with N' N dimethylformamide and methanol.

7. The composite film according to claim 5 or 6, wherein the heating temperature in step B is 100-150 ℃, the heating time is 1-24h, preferably the heating temperature is 110-140 ℃, and the heating time is 5-12 h;

preferably, the mass ratio of the metal-organic framework to the coupling agent addition in step B is from 1:1 to 1:4, preferably 1: 1.5-1: 2.5;

preferably, step B washes the product with N' N dimethylformamide and chloroform.

8. A method for preparing the degradable PBAT composite film according to any one of claims 1 to 7, which comprises the following steps:

C. mixing a small amount of talcum powder, a slipping agent, a chain extender and a modified metal organic framework, adding the talcum powder, PBAT and PLA into a main feeding port of a double-screw extruder, feeding the rest talcum powder from a side feeding port, and then performing melt extrusion, cooling, granulating and drying to obtain the PBAT modified alloy;

9. The preparation method according to claim 8, wherein the step C mixing is performed by a high speed mixer at a speed of 20-100 rpm, preferably 30-80 rpm; the mixing time is 3-10 min, preferably 5-7 min; the screw temperature of the plasticizing section of the double-screw extruder is 150-210 ℃, and preferably 160-200 ℃; the rotation speed is 100-800rpm, preferably 200-500 rpm;

preferably, the screw temperature of the film blowing machine is 130-180 ℃, preferably 140-160 ℃; the rotation speed is 5-30Hz, preferably 10-20 Hz.