阅读说明：本技术 可生物降解pbat聚合物、其制备方法、用途、农用地膜和制备方法 (Biodegradable PBAT polymer, preparation method and application thereof, agricultural mulching film and preparation method ) 是由 刘伯林 于 2021-04-21 设计创作，主要内容包括：本发明公开了一种可生物降解PBAT聚合物、其制备方法、用途、农用地膜和制备方法,属于聚合物制备技术领域。该方法包括：对苯二甲酸与己二酸配制成第一混合物；第一混合物、丁二醇配制成第二混合物；向第二混合物种加入催化剂,得到待打浆物料；制备功能粉体浆液；待打浆物料依次经过打浆、第一步酯化、第二步酯化后得到第一中间产物；第一中间产物、功能粉体浆液充分混合后,依次经过预缩聚、终缩聚、挤出、切粒、干燥后得到可生物降解PBAT聚合物。该聚合物经过聚合物的制备方法制备得到。该聚合物能够用于农用地膜,该农用地膜经由该PBAT聚合物在特性熔点条件下,吹膜后得到。该地膜对土壤几乎没有影响,能够取得较好的地膜效果,并且,成本低廉。(The invention discloses a biodegradable PBAT polymer, a preparation method and application thereof, an agricultural mulching film and a preparation method, and belongs to the technical field of polymer preparation. The method comprises the following steps: preparing a first mixture from terephthalic acid and adipic acid; preparing a second mixture from the first mixture and butanediol; adding a catalyst into the second mixed species to obtain a material to be pulped; preparing functional powder slurry; the material to be pulped is sequentially pulped, esterified in the first step and esterified in the second step to obtain a first intermediate product; and fully mixing the first intermediate product and the functional powder slurry, and sequentially carrying out pre-polycondensation, final polycondensation, extrusion, grain cutting and drying to obtain the biodegradable PBAT polymer. The polymer is prepared by a preparation method of the polymer. The polymer can be used for an agricultural mulching film, and the agricultural mulching film is obtained by blowing the PBAT polymer under the condition of a characteristic melting point. The mulching film has almost no influence on soil, can obtain a better mulching film effect, and has low cost.)

1. A method for preparing a biodegradable PBAT polymer, which is characterized by comprising the following steps:

preparing a first mixture from terephthalic acid and adipic acid according to the mass ratio of the substances ranging from (1:1) to (1: 1.5);

preparing a second mixture from the first mixture and butanediol according to the mass ratio range of (1:1) - (1: 1.5);

adding a catalyst into the second mixed species to obtain a material to be pulped, wherein the adding mass of the catalyst is 0.03-0.05% of the mass of the terephthalic acid;

preparing functional powder slurry, wherein the value range of the mass ratio of the functional powder, the tetrahydrofuran homopolyether and the butanediol is 40: (3-10): (40-60), wherein the value range of the mass ratio of the nano montmorillonite to the nano kaolin in the functional powder is 1 (3-5);

the material to be pulped is sequentially pulped, esterified in the first step and esterified in the second step to obtain a first intermediate product;

and fully mixing the first intermediate product and the functional powder slurry, and then sequentially carrying out pre-polycondensation, final polycondensation, extrusion, granulation and drying to obtain the biodegradable PBAT polymer, wherein the mass of the functional powder slurry is 30-40% of that of the terephthalic acid.

2. The method of claim 1 where the catalyst is selected from one or a mixture of tetrabutyl titanate and tetraisopropyl titanate.

3. The method for preparing a biodegradable PBAT polymer according to claim 1, characterized in that the duration of the beating step ranges from 30min to 50 min.

4. The method of preparing a biodegradable PBAT polymer according to claim 1, characterized in that the slurry obtained from the beating step is put into a supply tank for circulation for use.

5. The method of preparing biodegradable PBAT polymer according to claim 1, characterized in that during the first esterification step,

the temperature is 160-180 ℃;

the flow rate is 150kg/h-250 kg/h;

the liquid level depth range is 600mm-1000 mm;

the value range of the esterification rate is 51 to 55 percent.

6. The method of preparing a biodegradable PBAT polymer according to claim 1, characterized in that during the first esterification step, the slurry obtained from the beating step is pumped into a first esterification tank via a pump;

preferably, during the step of said second esterification step,

the temperature is 200-215 ℃;

the flow rate is 150kg/h-250 kg/h;

the value range of the liquid level depth is 600mm-1000 mm;

the value range of the ester exchange rate is 96-99 percent;

preferably, the preparation method of the functional powder comprises the following steps:

the value range of the mass ratio of the functional powder, the tetrahydrofuran homopolyether and the butanediol is 40: (3-10): (40-60) grinding in a ball mill for 50-70 min, wherein the mass ratio of the nano montmorillonite to the nano kaolin in the functional powder is 1 (3-5);

preferably, during the step of fully mixing the first intermediate product and the functional powder slurry,

the temperature is 210-215 ℃;

the flow rate is 210-215 ℃;

the value range of the liquid level depth is 800mm-1000 mm;

the value range of the stirring speed is 500rpm-900 rpm;

preferably, the functional powder slurry is added from a pipeline through which the esterified substance pumped out in the second esterification step flows;

preferably, during said step of prepolycondensation,

the temperature is 235-240 ℃;

the value range of the reaction duration is 40min-70 min;

the value range of the liquid level depth is 200mm-400 min;

the value range of the vacuum degree is 800Pa-1000 Pa;

preferably, during said step of final polycondensation,

the temperature is 245-255 ℃;

the reaction duration is 60min-80 min;

the value range of the liquid level depth is 300mm-500 mm;

the value range of the vacuum degree is 30Pa-100 Pa;

the intrinsic viscosity is in the range of 1.30dL/g to 1.35 dL/g.

7. A biodegradable PBAT polymer, characterized in that the biodegradable PBAT polymer is prepared by the method of any one of claims 1 to 6, the biodegradable PBAT polymer has a melting point in the range of 115 ℃ to 125 ℃ and a tensile strength in the range of 35MPa to 40 MPa; the elongation at break ranges from 600% to 650%, the hardness ranges from 60A to 65A, and the tear strength ranges from 170kN/m to 175 kN/m.

8. The biodegradable PBAT polymer of any of claims 1-6, prepared by a method of preparation, or the use of the biodegradable PBAT polymer of claim 7 for agricultural mulching films.

9. An agricultural mulching film, characterized in that the biodegradable PBAT polymer is prepared by the method for preparing biodegradable PBAT polymer as set forth in any one of claims 1 to 6, or the biodegradable PBAT polymer as set forth in claim 7.

10. A preparation method of an agricultural mulching film is characterized in that the biodegradable PBAT polymer is prepared by the preparation method of any one of claims 1-6, or the biodegradable PBAT polymer is obtained by blowing the film under the condition of a characteristic melting point.

Technical Field

The invention relates to the technical field of polymer preparation, in particular to a biodegradable PBAT polymer, a preparation method and application thereof, an agricultural mulching film and a preparation method.

Background

PBAT belongs to thermoplastic biodegradable plastic, the component of the PBAT is terephthalic acid-co-butanediol adipate, is a copolymer of the butanediol adipate and the butanediol terephthalate, has the characteristics of PBA and PBT, and has better ductility and elongation at break as well as better heat resistance and impact performance; in addition, the biodegradable plastic has excellent biodegradability, and is one of the best degradable materials which are very active in the research of the current biodegradable plastics and are applied to the market. PBAT is a semi-crystalline polymer, generally with a crystallization temperature around 110 ℃ and a melting point around 110 ℃ and 130 ℃ and a density between 1.18g/ml and 1.3 g/ml. The crystallinity of PBAT is about 30% and the Shore hardness is above 60A. However, in the prior art, the production cost of PBAT is high, and the prepared PBAT has poor moisture retention.

Disclosure of Invention

In view of the above, the present invention provides a biodegradable PBAT polymer, a preparation method, use, agricultural mulching film and a preparation method thereof, wherein the biodegradable PBAT polymer has almost no influence on soil when used as an agricultural mulching film, can achieve a good mulching film effect, and is low in cost, thereby being more practical.

In order to achieve the first object, the technical scheme of the biodegradable PBAT polymer provided by the invention is as follows:

the preparation method of the biodegradable PBAT polymer provided by the invention comprises the following steps:

preparing a first mixture from terephthalic acid and adipic acid according to the mass ratio of the substances ranging from (1:1) to (1: 1.5);

preparing a second mixture from the first mixture and butanediol according to the mass ratio range of (1:1) - (1: 1.5);

adding a catalyst into the second mixed species to obtain a material to be pulped, wherein the adding mass of the catalyst is 0.03-0.05% of the mass of the terephthalic acid;

preparing functional powder slurry, wherein the value range of the mass ratio of the functional powder, the tetrahydrofuran homopolyether and the butanediol is 40: (3-10): (40-60), wherein the value range of the mass ratio of the nano montmorillonite to the nano kaolin in the functional powder is 1 (3-5);

the material to be pulped is sequentially pulped, esterified in the first step and esterified in the second step to obtain a first intermediate product;

and fully mixing the first intermediate product and the functional powder slurry, and then sequentially carrying out pre-polycondensation, final polycondensation, extrusion, granulation and drying to obtain the biodegradable PBAT polymer, wherein the mass of the functional powder slurry is 30-40% of that of the terephthalic acid.

The biodegradable PBAT polymer provided by the invention can be further realized by adopting the following technical measures.

Preferably, the catalyst is selected from one or a mixture of two of tetrabutyl titanate and tetraisopropyl titanate.

Preferably, the duration time of the beating step ranges from 30min to 50 min.

Preferably, the slurry obtained in the pulping step is placed in a supply tank for standby circulation.

Preferably, during said first esterification step,

the temperature is 160-180 ℃;

the flow rate is 150kg/h-250 kg/h;

the liquid level depth range is 600mm-1000 mm;

the value range of the esterification rate is 51 to 55 percent.

Preferably, during the first esterification step, the slurry obtained in the beating step is pumped into a first esterification kettle through a pump.

Preferably, during the step of said second esterification step,

the temperature is 200-215 ℃;

the flow rate is 150kg/h-250 kg/h;

the value range of the liquid level depth is 600mm-1000 mm;

the value range of the ester exchange rate is 96 to 99 percent.

Preferably, the preparation method of the functional powder comprises the following steps:

the value range of the mass ratio of the functional powder, the tetrahydrofuran homopolyether and the butanediol is 40: (3-10): (40-60) grinding in a ball mill for 50-70 min, wherein the mass ratio of the nano montmorillonite to the nano kaolin in the functional powder is 1 (3-5).

Preferably, during the step of fully mixing the first intermediate product and the functional powder slurry,

the temperature is 210-215 ℃;

the flow rate is 210-215 ℃;

the value range of the liquid level depth is 800mm-1000 mm;

the stirring speed ranges from 500rpm to 900 rpm.

Preferably, the functional powder slurry is added from a pipeline through which the esterified substance pumped out in the step of the second esterification flows.

Preferably, during said step of prepolycondensation,

the temperature is 235-240 ℃;

the value range of the reaction duration is 40min-70 min;

the value range of the liquid level depth is 200mm-400 min;

the value range of the vacuum degree is 800Pa-1000 Pa.

Preferably, during said step of final polycondensation,

the temperature is 245-255 ℃;

the reaction duration is 60min-80 min;

the value range of the liquid level depth is 300mm-500 mm;

the value range of the vacuum degree is 30Pa-100 Pa;

the intrinsic viscosity is in the range of 1.30dL/g to 1.35 dL/g.

In order to achieve the second object, the biodegradable PBAT polymer provided by the present invention has the following technical scheme:

the biodegradable PBAT polymer provided by the invention is prepared by the preparation method of the biodegradable PBAT polymer provided by the invention, the melting point of the biodegradable PBAT polymer ranges from 115 ℃ to 125 ℃, and the tensile strength ranges from 35MPa to 40 MPa; the elongation at break ranges from 600% to 650%, the hardness ranges from 60A to 65A, and the tear strength ranges from 170kN/m to 175 kN/m.

In order to achieve the third object, the technical scheme of the application of the biodegradable PBAT polymer provided by the invention is as follows:

the biodegradable PBAT polymer prepared by the preparation method of the biodegradable PBAT polymer provided by the invention is used for agricultural mulching films.

In order to achieve the fourth object, the technical scheme of the agricultural mulching film provided by the invention is as follows:

the agricultural mulching film provided by the invention is prepared from the biodegradable PBAT polymer prepared by the preparation method of the biodegradable PBAT polymer provided by the invention.

In order to achieve the fifth object, the technical scheme of the preparation method of the agricultural mulching film provided by the invention is as follows:

the agricultural mulching film provided by the invention is obtained by blowing the biodegradable PBAT polymer provided by the invention under the condition of a characteristic melting point.

The agricultural mulching film obtained by blowing the biodegradable PBAT polymer provided by the invention is non-sticky and high in strength, and the film contains 19-20% of inorganic powder, wherein the inorganic powder is low in cost, the price is usually only 1/8-1/10 of the polymer, the cost of the film is greatly reduced, and the added inorganic powder is soil and hardly influences the soil. When the PBAT mulching film is used as a mulching film, under the same sunlight irradiation condition, after 12 hours, the temperature in the mulching film is 5-7 ℃ higher than that of the PBAT mulching film without functional powder, the humidity in the mulching film is 15-20%, and crops can be matured for 10-15 days earlier.

Detailed Description

In view of the above, the present invention provides a biodegradable PBAT polymer, a preparation method, use, agricultural mulching film and a preparation method thereof, wherein the biodegradable PBAT polymer has almost no influence on soil when used as an agricultural mulching film, can achieve a good mulching film effect, and is low in cost, thereby being more practical.

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the biodegradable PBAT polymer, its preparation method, its use, agricultural mulching film and its preparation method according to the present invention, and its specific implementation, structure, characteristics and effects will be made in conjunction with the preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, with the specific understanding that: both a and B may be included, a may be present alone, or B may be present alone, and any of the three cases can be provided.

Example 1

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.09 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 3, uniformly mixing the nano montmorillonite and the nano barium sulfate in proportion, wherein the nano montmorillonite and the nano barium sulfate are white powder in appearance, and the whiteness and the purity are as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 2

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.19 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 3, uniformly mixing the nano montmorillonite and the nano barium sulfate in proportion, wherein the nano montmorillonite and the nano barium sulfate are white powder in appearance, and the whiteness and the purity are as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 3

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.29 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 3, uniformly mixing the nano montmorillonite and the nano barium sulfate in proportion, wherein the nano montmorillonite and the nano barium sulfate are white powder in appearance, and the whiteness and the purity are as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 4

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.39 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 3, uniformly mixing the nano montmorillonite and the nano barium sulfate in proportion, wherein the nano montmorillonite and the nano barium sulfate are white powder in appearance, and the whiteness and the purity are as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 5

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.49 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 3, uniformly mixing the nano montmorillonite and the nano barium sulfate in proportion, wherein the nano montmorillonite and the nano barium sulfate are white powder in appearance, and the whiteness and the purity are as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 6

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.49 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 3.5, the nano montmorillonite and the nano barium sulfate are uniformly mixed in proportion, the appearance of the nano montmorillonite and the nano barium sulfate is white powder, the whiteness is 99, and the purity is as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 7

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.49 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 4.0, the nano montmorillonite and the nano barium sulfate are uniformly mixed, the appearance of the nano montmorillonite and the nano barium sulfate is white powder, the whiteness is 99, and the purity is as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 8

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.49 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 4.5, the nano montmorillonite and the nano barium sulfate are uniformly mixed according to the proportion, the appearance of the nano montmorillonite and the nano barium sulfate is white powder, the whiteness is 99, and the purity is as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 9

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.49 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 5.0, the nano montmorillonite and the nano barium sulfate are uniformly mixed, the appearance of the nano montmorillonite and the nano barium sulfate is white powder, the whiteness is 99, and the purity is as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Example 10

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.49 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

Functional powder, tetrahydrofuran polyether and butanediol are mixed according to the weight ratio of 40: 5: 55 putting into a ball mill, and grinding for 50min for standby. The functional slurry was metered into the conduit through which the esterified product pumped out of the second esterification reactor flowed by means of a conduit injector, and the amount of the functional slurry added was 60% of the mass of the PTA reactant, so that the flow rate was controlled at 115 kg/h. The functional powder is as follows: the nano montmorillonite-kaolin composite material is prepared from nano montmorillonite and nano kaolin according to a mass ratio of 1: 5.0, the nano montmorillonite and the nano barium sulfate are uniformly mixed, the appearance of the nano montmorillonite and the nano barium sulfate is white powder, the whiteness is 99, and the purity is as follows: 99.5%, mesh number 20nm, tetrahydrofuran homopolyether purity: 99.5% and a number average molecular weight of 500.

The obtained esterification mixture is pumped into a full mixing kettle for full mixing, the temperature of the full mixing kettle is controlled at 210 ℃, the flow rate is controlled at 150kg/h, the liquid level is maintained at 1000mm, and the stirring speed is 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the temperature of the melt to be 255 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared high-performance low-cost mulching film is blown by the PBAT polymer, the film blowing process is smooth, the blown film is uniform and is not adhered, and the method can be used for preparing the supermarket shopping bag film. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Comparative example 1

On a small-sized flexible modified polyester continuous polyester polycondensation production device with the daily yield of 8t-10t, the molar ratio of terephthalic acid to adipic acid is 1: 1.29 and butanediol, in a molar ratio of 1: 1.21, the catalyst is tetraisopropyl titanate. The addition amount thereof was 0.05% by mass of PTA. Pulping for 40min, and internally circulating in a pulp supply tank.

The obtained slurry is pumped into a first ester reaction kettle from a supply tank by a metering pump, the esterification reaction is carried out, the esterification temperature is controlled to be 170 ℃, the flow rate is controlled to be 200kg/h, the liquid level is maintained to be 1000mm, and the esterification rate reaches 52 percent. And (3) pumping the esterified substance into a second esterification reaction production kettle from the material to perform esterification reaction, wherein the temperature of the reactant is 215 ℃, and the flow rate is controlled at 200kg/h, so that the liquid level is maintained at 1000mm, and the esterification rate reaches 99%.

The obtained esterification mixture was pumped into a complete mixing kettle, the temperature of which was controlled at 210 ℃ and the flow rate was controlled at 150kg/h, so that the liquid level was maintained at 1000mm and the stirring speed was 500 rpm.

Pumping out the melt from the full mixing kettle, allowing the melt to enter a down-flow pre-polycondensation reaction kettle for pre-polycondensation reaction, and controlling the temperature of the melt to be 235 ℃ for 40 min; the liquid level was controlled at 300mm and the vacuum degree was controlled at 800 Pa.

Feeding the pre-polycondensation polymer into a final polycondensation kettle, and controlling the melt temperature to reach 245 ℃ for 60 min; the liquid level was controlled at 400mm and the vacuum degree at 50 Pa. After the intrinsic viscosity is 1.35dL/g through an online detection point, extruding, granulating, drying and packaging.

The prepared PBAT polymer is blown into films, the film blowing process is smooth, the blown films are uniform and are not bonded, and the PBAT polymer can be used for preparing supermarket shopping bag films. The processing temperature of the blown film is 155-175-170 ℃, and the thickness of the film is 5 mu m.

Tensile strength: the tensile strength of the product was tested by the GB/T4456 standard method. Elongation at break: the elongation at break of the product was tested by the GB/T4456 standard method, with greater elongation at break indicating better toughness of the product. Test standard for hardness ISO 868-2003. Test criteria for intrinsic viscosity: GB632-1993, tear strength test standard GB 6578. The ash content is measured by adopting a thermal weight loss analysis tester of Perkin Elmer in America, under the atmosphere of nitrogen, the gas flow is 100ml/min, the temperature range is 40-500 ℃, and the temperature rising speed is 10 ℃/min. The melting point was measured by DSC method, and the DSC temperature rise curve and temperature fall curve of the sample were measured by Perkin-Elmer Pyris type 1 differential scanning calorimeter. Before DSC test, the sample is cut into powder as much as possible, then a certain weight is weighed and sealed in a sample tray, and the weight of the sample is controlled to be 6mg-8 mg. N is a radical of₂The temperature is raised from 30 ℃ to 180 ℃ under the atmosphere at the temperature raising rate of 20 ℃/min; keeping the temperature for 5min to eliminate the thermal history, reducing the temperature to 30 ℃ at a cooling rate of 80 ℃/min, and recording respective curves. From the DSC chart, the melting point of PBAT can be derived. The temperature and humidity in the earth film are tested by a soil moisture temperature rapid tester with the standard of GB 7172-1987.

TABLE 1 PBAT Performance index Table

The PBAT polymer has the melting point of 115-125 ℃, the tensile strength of 35-40MPa, the elongation at break of 600-650%, the hardness of 60-65A, the tearing strength of 170-175KN/m, can be directly blown into a film, is not sticky, has high strength, and contains 19.0-20.0% of inorganic powder, wherein the cost of the inorganic powder is low, the price is usually only 1/8-1/10 of the polymer, the cost of the film is greatly reduced, and the added inorganic powder is almost free from influence on soil because the added inorganic powder is all soil. When the PBAT mulching film is used as a mulching film, under the same sunlight irradiation condition, after 12 hours, the temperature in the mulching film is 5-7 ℃ higher than that of the PBAT mulching film without functional powder, the humidity in the mulching film is 15-20%, and crops can be matured for 10-15 days earlier.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.