CN107955350B - Full-biodegradable drug-resistant mulching film composition and preparation method thereof - Google Patents
Full-biodegradable drug-resistant mulching film composition and preparation method thereof Download PDFInfo
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- CN107955350B CN107955350B CN201711254337.5A CN201711254337A CN107955350B CN 107955350 B CN107955350 B CN 107955350B CN 201711254337 A CN201711254337 A CN 201711254337A CN 107955350 B CN107955350 B CN 107955350B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
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- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G13/00—Protecting plants
- A01G13/02—Protective coverings for plants; Coverings for the ground; Devices for laying-out or removing coverings
- A01G13/0256—Ground coverings
- A01G13/0268—Mats or sheets, e.g. nets or fabrics
- A01G13/0275—Films
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
- C08J3/246—Intercrosslinking of at least two polymers
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2367/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2467/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2467/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/05—Alcohols; Metal alcoholates
- C08K5/053—Polyhydroxylic alcohols
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- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
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Abstract
A full-biodegradable drug-resistant mulching film composition is prepared from the following components in parts by weight: 100 parts of polylactic acid, 50-70 parts of poly (butylene adipate terephthalate) (PBAT), 5-10 parts of ethyl acetylcitrate, 5-10 parts of pentaerythritol, 0.1-0.5 part of ammonium persulfate, 0.1-1 part of antioxidant, 0.5-3 parts of ultraviolet-resistant auxiliary agent, 2-10 parts of drug resistance enhancer and 0.5-2 parts of nucleating agent. Under the initiation action of ammonium persulfate, polylactic acid and PBAT are subjected to a crosslinking reaction in extrusion, the molecular weight of the generated composition is increased, the strength is increased, the degradation is slow, and the drug resistance is enhanced.
Description
Technical Field
The invention belongs to the technical field of ground covering films, and particularly relates to a full-biodegradable drug-resistant mulching film composition and a preparation method thereof.
Background
Agricultural ground covering films (hereinafter referred to as mulching films) are used in the environment with low temperature, so that the survival rate of crops can be improved, and the effects of ripening and increasing yield of the crops are achieved, thereby being widely applied. In the prior art, the mulching film is prepared by blow molding of polyethylene, polyethylene raw materials are all derived from nonrenewable resources such as petrochemical industry and the like, and the long-term supply of the raw materials of the mulching film brings crisis and the cost is higher and higher along with the increasing shortage of petrochemical resources. Moreover, the polyethylene mulching film is not degradable or needs to be slowly degradable after being used, and white pollution is generally caused to the environment if the polyethylene mulching film is not treated, and a large amount of waste gas pollution is caused if the polyethylene mulching film is treated by burning. In addition, in the later stage of growth of crop seedlings, seedlings can grow healthily and freely only by bursting the mulching film, the seedlings can grow through the mulching film by using the existing polyethylene mulching film through manual puncturing, otherwise, the growth speed of crops is influenced, and even the crops grow abnormally.
In order to solve the problem of 'white pollution' caused by plastic products, the use of completely biodegradable polymers which are environmentally friendly instead of traditional petroleum-based plastics has become a hot spot of current research and development.
At present, most of the biodegradable materials reported in domestic and overseas research mainly comprise Polyhydroxyalkanoate (PHA) synthesized by microorganisms, Polyhydroxyalkanoate (PHA) and the like, and chemically synthesized polylactic acid (P L A), polycaprolactone (PC L), polybutylene succinate (PBS), aliphatic/aromatic copolyester, Aliphatic Polycarbonate (APC), polyvinyl alcohol (PVA), polybutylene adipate/terephthalate (PBAT) and the like, and part of the biodegradable materials are commercialized.
In the growth process of crops, the crops are inevitably disturbed by insect pests to cause yield reduction, the crops are inevitably required to be applied with pesticides in the growth process, but most of biodegradable materials are easily corroded by the pesticides, so that the degradable mulching film is broken and degraded in the growth period of the crops in advance, the service performance of the mulching film is reduced, and the growth of the crops is influenced.
The acid and alkali resistance of the polylactic acid is related to the structure of the polylactic acid, as more ester bonds exist in the polylactic acid fiber, the acid and alkali resistance is poor, the degradation of aliphatic polyester is accelerated under the acid or alkali condition, so that the relative molecular mass of the resin is reduced, most of pesticides on the market are acidic or alkali, the polylactic acid is easy to decompose too fast and prematurely when the pesticides are sprayed in the early growth stage of crops, or the polylactic acid is dissolved and broken, so that the heat preservation effect of the film is influenced, meanwhile, the P L A has the defect of serious brittleness, the application range of the film is limited to a great extent, and therefore, a full-biodegradable mulching film which is resistant to drugs and high in toughness needs to be developed, and the mulching film is not influenced when the pesticides are sprayed in the early growth stage of the crops.
At present, researchers at home and abroad improve the toughness of P L A by various means, mainly including copolymerization modification, plasticizer addition, filler addition, blending with other tough polymers and the like, wherein blending P L A with other tough polymers is one of the most common methods, because the method has higher efficiency in continuous industrial production.
Disclosure of Invention
The invention aims at providing a full-biodegradable drug-resistant mulching film composition due to the defects of the prior art and also aims at providing a preparation method of the mulching film composition.
The invention adopts pentaerythritol and ammonium persulfate, so that the pentaerythritol and the ammonium persulfate can react with P L A and PBAT in the processing process to reduce the tension between two phase interfaces, realize the high-efficiency fusion of P L A and PBAT, solve the problem of interface compatibility of P L A and PBAT, and simultaneously cooperate with other auxiliary agents, so that the film produced by the obtained full-biodegradable mulching film composition can resist the drug.
The invention relates to a full-biodegradable drug-resistant mulching film composition which is prepared from the following components in parts by weight:
100 parts of polylactic acid, 50-70 parts of poly (butylene adipate)/terephthalate, 5-10 parts of acetyl ethyl citrate, 5-10 parts of pentaerythritol, 0.1-0.5 part of ammonium persulfate, 0.1-1 part of antioxidant, 0.5-3 parts of ultraviolet-resistant auxiliary agent, 2-10 parts of drug-resistant additive and 0.5-2 parts of nucleating agent.
Wherein the polylactic acid is levorotatory light or racemic light polylactic acid, the number average molecular weight is between 3 and 15 ten thousand, the molecular weight distribution is between 1 and 2, and the crystallinity is between 20 and 60 percent.
The PBAT is a copolymer of butanediol adipate and butanediol terephthalate, has the characteristics of PBA and PBT, and has the density of 1.10-1.30 g/cm3The glass transition temperature is-25 to-35 ℃, the melting point is 110-120 ℃, and the product is produced by BASF corporation.
The acetyl ethyl citrate is acetylated on the basis of ethyl citrate, so that the binding force between the acetyl ethyl citrate and base resin is increased, a plasticizer is not precipitated, and the flexibility and the processing performance of the material are improved.
The pentaerythritol is white powder, is in industrial grade, can act on a resin two-phase interface, and can be used as a surfactant.
The nucleating agent is silicon dioxide.
The ammonium persulfate is white powder and is of industrial grade and is used as an initiator for reactive extrusion.
Wherein the antioxidant is preferably compounded by 2, 6-di-tert-butyl-4-methylphenol and 2, 4, 6-tri [2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -4-methyl-6-tert-butylphenol ] -cyanurate, and the weight ratio is 1: (0.5-1).
The anti-ultraviolet auxiliary agent is compounded by a light stabilizer UV-3853S and a light stabilizer Tinuvin 119, and the weight ratio is 1: 1, the light stabilizer UV-3853S is C12-21And C18Unsaturated fatty acid-2, 2, 6, 6-tetramethyl-4-piperidine ester, which has excellent light stability effect; the light stabilizer Tinuvin 119 is a triazine-piperidine condensate with high relative molecular mass, and the unique molecular structure enables the condensate to have acid resistance; low volatility and migration resistance.
The drug resistance increasing agent is preferably liquid paraffin, the dosage is preferably 3-8 parts, the dosage is too much, the strength of the film can be reduced, the dosage is too little, and the hydrophobicity of the blow-molded mulching film is poor; after the liquid paraffin is added, the liquid paraffin can play a role of a plasticizer, the finally prepared film has good hydrophobicity, and medicine drops dropping on the film are easy to roll off from the film when the medicine is sprayed, and are not easy to adhere to the film to cause corrosion and hydrolysis of the film.
The preparation method of the composition of the invention comprises the following steps:
1) drying polylactic acid and PBAT in a drying oven at 90 ℃ for 4-5 hours, and taking out for later use;
2) adding the dried polylactic acid, PBAT and other components into a mixer, stirring at high speed until the materials are completely and uniformly mixed for about 5-10 minutes, and then discharging the materials;
3) and (3) putting the mixed materials into a double-screw extruder for extrusion granulation, wherein the temperature of the double-screw extruder is 150-170 ℃, the feeding frequency is 20-25 Hz, and the rotating speed of a main machine is 80-100 r/min, and finally cooling and granulating to obtain the composition.
The above composition was blown into a film at a temperature of 170-195 ℃ to a thickness of 8-20 μm.
The invention has the following beneficial effects:
1) under the initiation action of ammonium persulfate, polylactic acid and PBAT are subjected to a crosslinking reaction in extrusion, the molecular weight of the generated composition is increased, the strength is increased, the degradation is slow, and the drug resistance is enhanced;
2) pentaerythritol can absorb residual carboxyl and slow down degradation;
3) meanwhile, the components of the composition are matched to obtain the super-hydrophobic film, and the contact angle between the film and water is between 150 DEG and 160 DEG, so that the drug resistance is further enhanced.
4) The film has good opening performance.
Detailed Description
The present invention will be further illustrated with reference to the following examples, but the present invention is not limited thereto.
In the examples, the polylactic acid is designated Revole 110, Zhejiang Haizhen biomaterial, density 1.25. + -. 0.05, melting point 140-.
In the examples, the PBAT is of the brand TH801, Dongguan kernel biodegradable plastics Co., Ltd, melting point 110-3。
The antioxidant is compounded by 2, 6-di-tert-butyl-4-methylphenol and 2, 4, 6-tri [2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -4-methyl-6-tert-butylphenol ] -cyanurate, and the weight ratio is 1: 1.
the anti-ultraviolet auxiliary agent is compounded by a light stabilizer UV-3853S and a light stabilizer Tinuvin 119, and the weight ratio is 1: 0.3; the drug resistance increaser is liquid paraffin.
TABLE 1 formulations, kg, of inventive examples 1-6
TABLE 2 formulations in kg for inventive examples 7-9 and comparative examples 1-4
When the ammonium persulfate in example 9 is replaced by DCP, the film is easy to generate crystal points during processing, is not easy to process and influences the mechanical properties of the film.
The preparation method of the above examples is as follows:
1) drying polylactic acid and PBAT in a 90 ℃ oven for 4 hours, and taking out for later use;
2) adding the dried polylactic acid, PBAT and other raw materials into a mixer, stirring at high speed until the materials are completely and uniformly mixed for about 5 minutes, and then discharging the materials;
3) and (3) putting the mixed materials into a double-screw extruder for extrusion granulation, wherein the temperature of the double-screw extruder is 150-170 ℃, the feeding frequency is 20-25 Hz, and the rotating speed of a main machine is 80-100 r/min, and finally cooling and granulating to obtain the composition.
The above composition was blown into a film at 170-195 ℃ to a thickness of 8 μm.
The performance of the examples and comparative examples of the invention is as follows:
table 3 results of performance tests of examples 1-6 of the present invention
TABLE 4 results of the performance test of inventive examples 7 to 9 and comparative examples 1 to 3
The contact angle of the film and water is tested according to the standard GB T30693-2014, the tensile strength is tested according to GB/T1040-2006, the ultraviolet light aging is tested according to GB/T16422-2006, the light transmittance of the film is tested according to GB/T2410-2008, the thickness of the film is 0.01mm, 10 layers are overlapped, and the soaked pesticide is a mixture of triazophos serving as an insecticide and paraquat serving as a herbicide.
As can be seen from the design results of the examples and the comparative examples, the drug resistance, the hydrophobicity and the strength of the film produced by the invention are obviously superior to those of the comparative example.
The invention selects the examples 8-9 and the comparative examples 1-3 and the common PE film with the thickness of 8 mu m to carry out cotton planting test in Xinjiang, the test is carried out in 2015 in 4 months in Xinjiang for producing and constructing arm groups, the soil type of the test field is grey desert soil, and the texture is medium soil; the annual average temperature is 6.5 ℃, the frost-free period is about 160d, and the conditions of soil, water, fertilizer, medicine and the like in each test group are consistent.
The cotton yield with different mulch films is shown in table 5.
TABLE 5 Cotton yield with different mulch films
As can be seen from tables 4 and 5, the comparative examples are affected by pesticides, rainwater and the like, and are degraded too early, poor in heat preservation performance in the early stage of growth and relatively low in cotton yield.
The foregoing describes the general principles and features of the present invention without limitation to the above-described embodiments, and various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the claimed invention.
Claims (3)
1. The full-biodegradable drug-resistant mulching film composition is characterized by comprising the following components in parts by weight: 100 parts of polylactic acid, 52 parts of poly (butylene adipate)/terephthalate, 6 parts of acetyl ethyl citrate, 7 parts of pentaerythritol, 0.4 part of ammonium persulfate, 0.9 part of antioxidant, 1 part of ultraviolet-resistant auxiliary agent, 8 parts of drug-resistant additive and 0.8 part of nucleating agent;
the polylactic acid is Revode 110;
the grade of the polybutylene adipate/terephthalate is TH 801;
the antioxidant is compounded by 2, 6-di-tert-butyl-4-methylphenol and 2, 4, 6-tris [2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -4-methyl-6-tert-butylphenol ] -cyanurate in a weight ratio of 1: 1;
the anti-ultraviolet auxiliary agent is compounded by a light stabilizer UV-3853S and a light stabilizer Tinuvin 119, and the weight ratio is 1: 0.3; the drug resistance increaser is liquid paraffin.
2. The fully biodegradable drug-resistant mulching film composition according to claim 1, wherein the nucleating agent is silica.
3. The preparation method of the full-biodegradable drug-resistant mulching film composition according to claim 1, characterized by comprising the following steps in sequence:
1) firstly, drying polylactic acid and poly adipic acid/butylene terephthalate in an oven at 90 ℃ for 4-5 hours, and taking out for later use;
2) adding the dried polylactic acid, the poly adipic acid/butylene terephthalate and other components into a mixer, stirring at high speed until the materials are completely and uniformly mixed for 5-10 minutes, and then discharging the materials;
3) and (3) putting the mixed materials into a double-screw extruder for extrusion granulation, wherein the temperature of the double-screw extruder is 150-170 ℃, the feeding frequency is 20-25 Hz, the rotating speed of a main machine is 80-100 r/min, and finally, cooling and granulating to obtain the composition.
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| ITMI20120737A1 (en) * | 2012-05-03 | 2013-11-04 | Univ Pisa | POLYESTER BASED COPOLYMERS AND REACTIVE PLASTICANTS FOR THE PRODUCTION OF TRANSPARENT AND BIODEGRADABLE PACKAGING FILM |
| CN103589124B (en) * | 2012-08-14 | 2016-12-07 | 上海杰事杰新材料(集团)股份有限公司 | A kind of complete biodegradable PLA/PBAT laminated film and preparation method thereof |
| CN103709695B (en) * | 2013-12-26 | 2016-02-03 | 安徽聚美生物科技有限公司 | A kind of PLA is material modified and preparation method thereof and PLA Biodegradable mulch |
| CN104559087A (en) * | 2015-01-21 | 2015-04-29 | 江苏科技大学 | Controllable bio-based full-degradable mulching film |
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