Disclosure of Invention
The invention aims to provide a degradable heat-preservation plastic mulching film and a preparation method thereof, and aims to solve the problems in the prior art.
A degradable heat-preservation plastic mulching film is characterized by mainly comprising the following raw material components in parts by weight: 50-80 parts of polybutylene adipate terephthalate and 10-30 parts of mixed additives.
As optimization, raw materials for preparing the additive comprise modified lignin, hollow titanium dioxide, modified cellulose, ammonia water, chitosan quaternary ammonium salt, hexadecyl trimethoxy siloxane, an insecticide and oxidized glucan.
As optimization, the modified lignin is prepared by treating sodium lignosulfonate with phloroglucinol and 1, 4-dibromobutane; the modified cellulose is prepared by treating bacterial cellulose with maleic anhydride.
Preferably, the pesticide is any one of anthranilic acid or deltamethrin.
As optimization, the degradable heat-preservation plastic mulching film mainly comprises the following raw material components in parts by weight: 80 parts of polybutylene adipate terephthalate and 20 parts of mixed additives.
As optimization, the preparation method of the degradable heat-preservation plastic mulching film mainly comprises the following preparation steps:
(1) mixing phloroglucinol and 1, 4-dibromobutane in ethanol, stirring for reaction to obtain a modified phloroglucinol mixture, extracting the modified phloroglucinol mixture with petroleum ether, then adding potassium iodide and sodium lignosulfonate, adjusting the pH value to be alkaline, stirring for reaction, dialyzing, and freeze-drying to obtain modified lignin;
(2) mixing the modified lignin obtained in the step (1) and hollow titanium dioxide in water, stirring and mixing, filtering, and drying to obtain modified titanium dioxide;
(3) mixing bacterial cellulose with an organic solvent, adding maleic anhydride and an initiator, stirring and mixing, filtering, and washing to obtain modified cellulose;
(4) mixing the modified cellulose obtained in the step (3) with ammonia water to obtain modified cellulose mixed dispersion liquid, mixing the modified titanium dioxide obtained in the step (2) with water, adding ammonium persulfate, stirring and mixing, then dropwise adding the modified cellulose mixed dispersion liquid, stirring and reacting, then adding epoxy chloropropane, stirring and reacting, freeze-drying, and crushing to obtain a mixed additive blank;
(5) mixing the mixed additive blank obtained in the step (4) with a chitosan quaternary ammonium salt solution, adding an insecticide, stirring and mixing, then adding oxidized dextran, stirring and reacting, filtering to obtain a pretreated mixed additive blank, adding the pretreated mixed additive blank and hexadecyl trimethoxy siloxane into a hydrothermal kettle, and carrying out hydrothermal reaction to obtain a mixed additive;
(6) weighing the following components in parts by weight: 50-75 parts of polybutylene adipate-terephthalate and 10-30 parts of additives, mixing the polybutylene adipate-terephthalate with dichloromethane, adding the additives, stirring and mixing, coating, uncovering and drying to obtain a degradable heat-preservation plastic mulching film blank, and performing ultrasonic treatment on the degradable heat-preservation plastic mulching film blank to obtain the degradable heat-preservation plastic mulching film.
As optimization, the preparation method of the degradable heat-preservation plastic mulching film mainly comprises the following preparation steps:
(1) mixing phloroglucinol and 1, 4-dibromobutane according to a molar ratio of 1: 1, mixing the mixture in a beaker, adding ethanol with the molar mass of phloroglucinol being 8-15 times of that of the mixture into the beaker, stirring the mixture at the temperature of 80 ℃ for reaction for 9-13 hours to obtain a modified phloroglucinol mixture, extracting the modified phloroglucinol mixture by using petroleum ether to remove 1, 4-dibromobutane, adding potassium iodide with the mass of the modified phloroglucinol mixture being 0.01-0.05 time of that of the modified phloroglucinol mixture and sodium lignosulfonate with the mass of the modified phloroglucinol mixture being 0.1-0.4 time of that of the modified phloroglucinol mixture into the modified phloroglucinol mixture, adjusting the pH value to 11, stirring the mixture at the temperature of 80 ℃ for reaction for 5 hours to obtain a modified lignin blank, dialyzing the modified lignin blank by using a dialysis bag with the molecular weight of 1000 for 6-10 hours, and freezing and drying the modified lignin to obtain the modified lignin;
(2) mixing the modified lignin obtained in the step (1) with hollow titanium dioxide according to the mass ratio of 3: 1-5: 1, mixing the raw materials in water with the mass 8-12 times of that of the modified lignin, stirring and mixing, filtering to obtain a modified titanium dioxide blank, and drying the modified titanium dioxide blank at the temperature of 80-90 ℃ for 1-3 hours to obtain modified titanium dioxide;
(3) mixing bacterial cellulose and acetone according to a mass ratio of 1: 30-1: 50, mixing the mixture in a flask, adding maleic anhydride with the mass of 0.1-0.3 time of that of bacterial cellulose and diisopropylamine with the mass of 0.1-0.2 time of that of the bacterial cellulose into the flask, stirring and reacting for 40-50 h at room temperature, filtering to obtain a modified cellulose blank, and washing the modified cellulose blank with absolute ethyl alcohol for 3-5 times to obtain modified cellulose;
(4) mixing the modified cellulose obtained in the step (3) with ammonia water with the mass fraction of 10-15% according to the mass ratio of 1: 8-1: 15 to obtain a modified cellulose mixed dispersion liquid, and mixing the modified titanium dioxide obtained in the step (2) with water according to a mass ratio of 1: 50-1: 60, mixing the mixture in a reaction kettle, adding ammonium persulfate which is 0.6-0.8 times of the mass of the modified titanium dioxide into the reaction kettle, stirring and mixing, then dropwise adding a modified cellulose mixed dispersion liquid which is 60-100 times of the mass of the modified titanium dioxide into the reaction kettle at the speed of 10-40 drops/min, stirring and reacting for 6-18 hours at the temperature of 30-50 ℃ and the rotating speed of 300-500 r/min, then adding epoxy chloropropane which is 0.2-0.6 times of the mass of the modified titanium dioxide into the reaction, stirring and reacting for 1-5 hours at the temperature of 40-50 ℃, freeze drying, and crushing to obtain a mixed additive blank;
(5) mixing the mixed additive blank obtained in the step (4) with the chitosan quaternary ammonium salt solution according to the mass ratio of 1: 10-1: 12, mixing the mixture in a three-neck flask, adding anthranilic acid with the mass 1-2 times that of a mixed additive blank into the three-neck flask, stirring and mixing, adding oxidized glucan with the mass 0.2-0.4 times that of the mixed additive blank into the three-neck flask, stirring and reacting, filtering to obtain a pretreated mixed additive blank, adding the pretreated mixed additive blank and hexadecyl trimethoxy siloxane into a hydrothermal kettle, keeping the hexadecyl trimethoxy siloxane from contacting with the pretreated additive blank, and carrying out hydrothermal treatment at the temperature of 110 ℃ for 2 hours to obtain a mixed additive;
(6) weighing the following components in parts by weight: 80 parts of polybutylene adipate-terephthalate and 20 parts of mixed additive, mixing the polybutylene adipate-terephthalate and dichloromethane in a stirrer, adding the mixed additive, stirring and mixing to obtain a coating solution, coating the coating solution for 3 times, controlling the interval between every two coating to be 10-20 s, uncovering the coating, drying for 1-3 h at the temperature of 60-70 ℃ to obtain a degradable heat-preservation plastic mulching film blank, and carrying out ultrasonic treatment on the degradable heat-preservation plastic mulching film blank for 1-2 min at the frequency of 20-40 kHz to obtain the degradable heat-preservation plastic mulching film.
Optimally, the preparation method of the hollow titanium dioxide in the step (2) comprises the following steps of mixing the crosslinked polystyrene microspheres with the mixed acid liquor according to the mass ratio of 1: 60-1: 100, stirring and reacting, filtering, washing until a washing solution is neutral to obtain a nitrated polystyrene microsphere, and mixing the nitrated polystyrene microsphere with a 10-15% sodium hydroxide solution according to a mass ratio of 1: 12-1: 20, adding potassium persulfate which is 0.2-0.4 times of the mass of the nitrated polystyrene microsphere, stirring for reaction, and filtering to obtain an aminated polystyrene microsphere; mixing aminated polystyrene microspheres with an ethanol solution with the mass fraction of 80% according to the mass ratio of 1: 50, adding glacial acetic acid with the mass 1-5 times that of the aminated polystyrene microsphere, stirring and mixing, then dripping a tetrabutyl titanate ethanol solution with the mass fraction of 40% at the speed of 20-60 drops/min, stirring and reacting for 2 hours at the temperature of 40 ℃, filtering to obtain microspheres, calcining the microspheres for 1-3 hours at the temperature of 400-600 ℃, and discharging to obtain the hollow titanium dioxide.
Compared with the prior art, the invention has the beneficial effects that:
the invention adds the mixed additive when preparing the degradable heat-preservation plastic mulching film.
Firstly, the mixed additive contains hollow titanium dioxide, the surface of the titanium dioxide is hydrophobic after being treated by modified lignin and modified cellulose, and the titanium dioxide can be uniformly dispersed in polybutylene adipate-terephthalate after being added into the polybutylene adipate-terephthalate, so that the void ratio in the product is improved, and the heat insulation performance of the product is improved;
secondly, modified cellulose is added into the mixed additive, the modified cellulose can form an aerogel structure around titanium dioxide in the preparation process of the mixed additive, the introduction of the aerogel structure can improve the bonding force among molecular chains in the product, so that the strength of the product is improved, and the heat insulation performance of the product is improved at the same time, and meanwhile, oxidized glucan and chitosan quaternary ammonium salt are also added in the preparation process of the mixed additive, so that the gaps of the aerogel can be further enriched, and the heat insulation performance of the product is further improved;
furthermore, hollow titanium dioxide surface is by the cladding of modified lignin in the mixed additive, and the cladding has the aerogel structure of hydrophobic oleophylic modification outside the modified lignin, in the product use, because garlic can volatilize allicin and allicin when ripe, allicin and allicin can double aerogel structure and adsorb, thereby make the modified lignin desorption on titanium dioxide surface, and then let titanium dioxide expose, thereby impel the degradation of product, and then make the product can degrade fast after the garlic is ripe, do not influence the planting of follow-up plant, simultaneously because the exposure of titanium dioxide, can make the insecticide among the mixed additive begin to release, and then can protect ripe garlic, prevent that the pest from gnawing and stinging.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to more clearly illustrate the method provided by the invention, the following examples are used for detailed description, and the method for testing each index of the degradable thermal insulation plastic mulching film manufactured in the following examples is as follows:
mechanical properties: the degradable thermal insulation plastic mulching films obtained in the examples and the comparative examples are tested according to GB/T1040.1 for breaking strength.
Thermal insulation performance: the thermal conductivity of the degradable thermal insulation plastic mulching film obtained in each example and the comparative product is measured.
Degradability: the weight loss rate of the degradable heat-preservation plastic mulching films obtained in the examples and the comparative products after 15 days under simulated illumination conditions is measured, and the weight loss rate of the degradable heat-preservation plastic mulching films obtained in the examples and the comparative products after 24 hours of fumigating with allicin under simulated illumination conditions is measured within 10 days.
Example 1
A degradable thermal insulation plastic mulching film mainly comprises the following components in parts by weight: 80 parts of polybutylene adipate terephthalate and 20 parts of mixed additives.
A preparation method of a degradable heat-preservation plastic mulching film mainly comprises the following preparation steps:
(1) mixing phloroglucinol and 1, 4-dibromobutane according to a molar ratio of 1: 1, mixing the modified phloroglucinol with ethanol, adding ethanol with the molar mass being 10 times that of phloroglucinol into a beaker, stirring and reacting for 11 hours at the temperature of 80 ℃ to obtain a modified phloroglucinol mixture, extracting the modified phloroglucinol mixture with petroleum ether to remove 1, 4-dibromobutane, adding potassium iodide with the mass being 0.03 time that of the modified phloroglucinol mixture and sodium lignosulfonate with the mass being 0.3 time that of the modified phloroglucinol mixture into the modified phloroglucinol mixture, adjusting the pH value to 11, stirring and reacting for 5 hours at the temperature of 80 ℃ to obtain a modified lignin blank, dialyzing the modified lignin blank for 8 hours by using a dialysis bag with the molecular weight cutoff of 1000, and freeze-drying to obtain the modified lignin;
(2) mixing the modified lignin obtained in the step (1) with hollow titanium dioxide according to a mass ratio of 4: 1, mixing the raw materials in water with the mass of 10 times that of the modified lignin, stirring and mixing the raw materials, filtering the mixture to obtain a modified titanium dioxide blank, and drying the modified titanium dioxide blank for 2 hours at the temperature of 85 ℃ to obtain modified titanium dioxide;
(3) mixing bacterial cellulose and acetone according to a mass ratio of 1: 40, mixing the mixture in a flask, adding maleic anhydride with the mass of 0.2 time that of the bacterial cellulose and diisopropylamine with the mass of 0.15 time that of the bacterial cellulose into the flask, stirring the mixture for reaction for 45 hours at room temperature, filtering the mixture to obtain a modified cellulose blank, and washing the modified cellulose blank with absolute ethyl alcohol for 4 times to obtain modified cellulose;
(4) mixing the modified cellulose obtained in the step (3) with 12% ammonia water according to a mass ratio of 1: 10 to obtain a modified cellulose mixed dispersion liquid, and mixing the modified titanium dioxide obtained in the step (2) with water according to a mass ratio of 1: 55, adding ammonium persulfate which is 0.7 time of the mass of the modified titanium dioxide into the reaction kettle, stirring and mixing, then adding modified cellulose mixed dispersion liquid which is 80 times of the mass of the modified titanium dioxide into the reaction kettle in a dropwise manner at the speed of 35 drops/min, stirring and reacting for 12 hours at the temperature of 40 ℃ and the rotating speed of 400r/min, then adding epoxy chloropropane which is 0.4 time of the mass of the modified titanium dioxide into the reaction, stirring and reacting for 3 hours at the temperature of 45 ℃, freeze-drying and crushing to obtain a mixed additive blank;
(5) mixing the mixed additive blank obtained in the step (4) with the chitosan quaternary ammonium salt solution according to the mass ratio of 1: 10, mixing the mixture in a three-neck flask, adding anthranilic acid with the mass 1.5 times that of a mixed additive blank into the three-neck flask, stirring and mixing, adding oxidized glucan with the mass 0.3 times that of the mixed additive blank into the three-neck flask, stirring and reacting for 3 hours at the temperature of 60 ℃, filtering to obtain a pretreated mixed additive blank, adding the pretreated mixed additive blank and hexadecyl trimethoxy siloxane into a hydrothermal kettle, wherein the hexadecyl trimethoxy siloxane is not in contact with the pretreated additive blank, and performing hydrothermal treatment for 2 hours at the temperature of 110 ℃ to obtain a mixed additive;
(6) weighing the following components in parts by weight: 80 parts of polybutylene adipate-terephthalate and 20 parts of mixed additive, namely mixing the polybutylene adipate-terephthalate and dichloromethane in a stirrer, adding the mixed additive, stirring and mixing to obtain a coating solution, coating the coating solution for 3 times, controlling the interval between every two coatings to be 15s, uncovering the coatings, drying for 2 hours at the temperature of 70 ℃ to obtain a degradable heat-preservation plastic mulching film blank, and carrying out ultrasonic treatment on the degradable heat-preservation plastic mulching film blank for 1min at the frequency of 40kHz to obtain the degradable heat-preservation plastic mulching film.
Optimally, the preparation method of the hollow titanium dioxide in the step (2) comprises the following steps of mixing the crosslinked polystyrene microspheres with the mixed acid liquor according to the mass ratio of 1: 80, stirring for reaction, filtering, washing until the washing liquid is neutral to obtain the nitrated polystyrene microsphere, wherein the nitrated polystyrene microsphere comprises the following components in percentage by mass: 12% of sodium hydroxide solution according to the mass ratio of 1: 15, adding potassium persulfate which is 0.3 time of the mass of the nitrated polystyrene microsphere, stirring for reaction, and filtering to obtain an aminated polystyrene microsphere; mixing aminated polystyrene microspheres with an ethanol solution with the mass fraction of 80% according to the mass ratio of 1: 50, adding glacial acetic acid with the mass 3 times that of the aminated polystyrene microsphere, stirring and mixing, then dripping a tetrabutyl titanate ethanol solution with the mass fraction of 40% at the speed of 55 drops/min, stirring and reacting for 2 hours at the temperature of 40 ℃, filtering to obtain microspheres, calcining the microspheres for 2 hours at the temperature of 500 ℃, and discharging to obtain the hollow titanium dioxide.
Example 2
A degradable thermal insulation plastic mulching film mainly comprises the following components in parts by weight: 80 parts of polybutylene adipate terephthalate and 20 parts of mixed additives.
A preparation method of a degradable heat-preservation plastic mulching film mainly comprises the following preparation steps:
(1) mixing phloroglucinol and 1, 4-dibromobutane according to a molar ratio of 1: 1, mixing the modified phloroglucinol with ethanol, adding ethanol with the molar mass being 10 times that of phloroglucinol into a beaker, stirring and reacting for 11 hours at the temperature of 80 ℃ to obtain a modified phloroglucinol mixture, extracting the modified phloroglucinol mixture with petroleum ether to remove 1, 4-dibromobutane, adding potassium iodide with the mass being 0.03 time that of the modified phloroglucinol mixture and sodium lignosulfonate with the mass being 0.3 time that of the modified phloroglucinol mixture into the modified phloroglucinol mixture, adjusting the pH value to 11, stirring and reacting for 5 hours at the temperature of 80 ℃ to obtain a modified lignin blank, dialyzing the modified lignin blank for 8 hours by using a dialysis bag with the molecular weight cutoff of 1000, and freeze-drying to obtain the modified lignin;
(2) mixing the modified lignin obtained in the step (1) with hollow titanium dioxide according to a mass ratio of 4: 1, mixing the raw materials in water with the mass of 10 times that of the modified lignin, stirring and mixing the raw materials, filtering the mixture to obtain a modified titanium dioxide blank, and drying the modified titanium dioxide blank for 2 hours at the temperature of 85 ℃ to obtain modified titanium dioxide;
(3) mixing bacterial cellulose and 12% ammonia water in a mass ratio of 1: 10 to obtain a bacterial cellulose mixed dispersion liquid, and mixing the modified titanium dioxide obtained in the step (2) with water according to a mass ratio of 1: 55, adding ammonium persulfate which is 0.7 time of the mass of the modified titanium dioxide into the reaction kettle, stirring and mixing, then adding bacterial cellulose mixed dispersion liquid which is 80 times of the mass of the modified titanium dioxide into the reaction kettle in a dropwise manner at the speed of 35 drops/min, stirring and reacting for 12 hours at the temperature of 40 ℃ and the rotating speed of 400r/min, then adding epoxy chloropropane which is 0.4 time of the mass of the modified titanium dioxide into the reaction, stirring and reacting for 3 hours at the temperature of 45 ℃, and then freeze-drying and crushing to obtain a mixed additive blank;
(4) mixing the mixed additive blank obtained in the step (3) with the chitosan quaternary ammonium salt solution according to the mass ratio of 1: 10, mixing the mixture in a three-neck flask, adding anthranilic acid with the mass 1.5 times that of a mixed additive blank into the three-neck flask, stirring and mixing, adding oxidized glucan with the mass 0.3 times that of the mixed additive blank into the three-neck flask, stirring and reacting for 3 hours at the temperature of 60 ℃, filtering to obtain a pretreated mixed additive blank, adding the pretreated mixed additive blank and hexadecyl trimethoxy siloxane into a hydrothermal kettle, wherein the hexadecyl trimethoxy siloxane is not in contact with the pretreated additive blank, and performing hydrothermal treatment for 2 hours at the temperature of 110 ℃ to obtain a mixed additive;
(5) weighing the following components in parts by weight: 80 parts of polybutylene adipate-terephthalate and 20 parts of mixed additive, namely mixing the polybutylene adipate-terephthalate and dichloromethane in a stirrer, adding the mixed additive, stirring and mixing to obtain a coating solution, coating the coating solution for 3 times, controlling the interval between every two coatings to be 15s, uncovering the coatings, drying for 2 hours at the temperature of 70 ℃ to obtain a degradable heat-preservation plastic mulching film blank, and carrying out ultrasonic treatment on the degradable heat-preservation plastic mulching film blank for 1min at the frequency of 40kHz to obtain the degradable heat-preservation plastic mulching film.
Optimally, the preparation method of the hollow titanium dioxide in the step (2) comprises the following steps of mixing the crosslinked polystyrene microspheres with the mixed acid liquor according to the mass ratio of 1: 80, stirring for reaction, filtering, washing until the washing liquid is neutral to obtain the nitrated polystyrene microsphere, wherein the nitrated polystyrene microsphere comprises the following components in percentage by mass: 12% of sodium hydroxide solution according to the mass ratio of 1: 15, adding potassium persulfate which is 0.3 time of the mass of the nitrated polystyrene microsphere, stirring for reaction, and filtering to obtain an aminated polystyrene microsphere; mixing aminated polystyrene microspheres with an ethanol solution with the mass fraction of 80% according to the mass ratio of 1: 50, adding glacial acetic acid with the mass 3 times that of the aminated polystyrene microsphere, stirring and mixing, then dripping a tetrabutyl titanate ethanol solution with the mass fraction of 40% at the speed of 55 drops/min, stirring and reacting for 2 hours at the temperature of 40 ℃, filtering to obtain microspheres, calcining the microspheres for 2 hours at the temperature of 500 ℃, and discharging to obtain the hollow titanium dioxide.
Example 3
A degradable thermal insulation plastic mulching film mainly comprises the following components in parts by weight: 80 parts of polybutylene adipate terephthalate and 20 parts of mixed additives.
A preparation method of a degradable heat-preservation plastic mulching film mainly comprises the following preparation steps:
(1) mixing lignin and hollow titanium dioxide according to a mass ratio of 4: 1, mixing the raw materials in water with the mass of 10 times that of the modified lignin, stirring and mixing the raw materials, filtering the mixture to obtain a modified titanium dioxide blank, and drying the modified titanium dioxide blank for 2 hours at the temperature of 85 ℃ to obtain modified titanium dioxide;
(2) mixing bacterial cellulose and acetone according to a mass ratio of 1: 40, mixing the mixture in a flask, adding maleic anhydride with the mass of 0.2 time that of the bacterial cellulose and diisopropylamine with the mass of 0.15 time that of the bacterial cellulose into the flask, stirring the mixture for reaction for 45 hours at room temperature, filtering the mixture to obtain a modified cellulose blank, and washing the modified cellulose blank with absolute ethyl alcohol for 4 times to obtain modified cellulose;
(3) mixing the modified cellulose obtained in the step (2) with 12% ammonia water in a mass ratio of 1: 10 to obtain a modified cellulose mixed dispersion liquid, and mixing the modified titanium dioxide obtained in the step (1) with water according to a mass ratio of 1: 55, adding ammonium persulfate which is 0.7 time of the mass of the modified titanium dioxide into the reaction kettle, stirring and mixing, then adding modified cellulose mixed dispersion liquid which is 80 times of the mass of the modified titanium dioxide into the reaction kettle in a dropwise manner at the speed of 35 drops/min, stirring and reacting for 12 hours at the temperature of 40 ℃ and the rotating speed of 400r/min, then adding epoxy chloropropane which is 0.4 time of the mass of the modified titanium dioxide into the reaction, stirring and reacting for 3 hours at the temperature of 45 ℃, freeze-drying and crushing to obtain a mixed additive blank;
(4) mixing the mixed additive blank obtained in the step (3) with the chitosan quaternary ammonium salt solution according to the mass ratio of 1: 10, mixing the mixture in a three-neck flask, adding anthranilic acid with the mass 1.5 times that of a mixed additive blank into the three-neck flask, stirring and mixing, adding oxidized glucan with the mass 0.3 times that of the mixed additive blank into the three-neck flask, stirring and reacting for 3 hours at the temperature of 60 ℃, filtering to obtain a pretreated mixed additive blank, adding the pretreated mixed additive blank and hexadecyl trimethoxy siloxane into a hydrothermal kettle, wherein the hexadecyl trimethoxy siloxane is not in contact with the pretreated additive blank, and performing hydrothermal treatment for 2 hours at the temperature of 110 ℃ to obtain a mixed additive;
(5) weighing the following components in parts by weight: 80 parts of polybutylene adipate-terephthalate and 20 parts of mixed additive, namely mixing the polybutylene adipate-terephthalate and dichloromethane in a stirrer, adding the mixed additive, stirring and mixing to obtain a coating solution, coating the coating solution for 3 times, controlling the interval between every two coatings to be 15s, uncovering the coatings, drying for 2 hours at the temperature of 70 ℃ to obtain a degradable heat-preservation plastic mulching film blank, and carrying out ultrasonic treatment on the degradable heat-preservation plastic mulching film blank for 1min at the frequency of 40kHz to obtain the degradable heat-preservation plastic mulching film.
As an optimization, the preparation method of the hollow titanium dioxide in the step (1) comprises the following steps of mixing the crosslinked polystyrene microspheres with the mixed acid solution according to a mass ratio of 1: 80, stirring for reaction, filtering, washing until the washing liquid is neutral to obtain the nitrated polystyrene microsphere, wherein the nitrated polystyrene microsphere comprises the following components in percentage by mass: 12% of sodium hydroxide solution according to the mass ratio of 1: 15, adding potassium persulfate which is 0.3 time of the mass of the nitrated polystyrene microsphere, stirring for reaction, and filtering to obtain an aminated polystyrene microsphere; mixing aminated polystyrene microspheres with an ethanol solution with the mass fraction of 80% according to the mass ratio of 1: 50, adding glacial acetic acid with the mass 3 times that of the aminated polystyrene microsphere, stirring and mixing, then dripping a tetrabutyl titanate ethanol solution with the mass fraction of 40% at the speed of 55 drops/min, stirring and reacting for 2 hours at the temperature of 40 ℃, filtering to obtain microspheres, calcining the microspheres for 2 hours at the temperature of 500 ℃, and discharging to obtain the hollow titanium dioxide.
Example 4
A degradable thermal insulation plastic mulching film mainly comprises the following components in parts by weight: 80 parts of polybutylene adipate terephthalate and 20 parts of mixed additives.
A preparation method of a degradable heat-preservation plastic mulching film mainly comprises the following preparation steps:
(1) mixing phloroglucinol and 1, 4-dibromobutane according to a molar ratio of 1: 1, mixing the modified phloroglucinol with ethanol, adding ethanol with the molar mass being 10 times that of phloroglucinol into a beaker, stirring and reacting for 11 hours at the temperature of 80 ℃ to obtain a modified phloroglucinol mixture, extracting the modified phloroglucinol mixture with petroleum ether to remove 1, 4-dibromobutane, adding potassium iodide with the mass being 0.03 time that of the modified phloroglucinol mixture and sodium lignosulfonate with the mass being 0.3 time that of the modified phloroglucinol mixture into the modified phloroglucinol mixture, adjusting the pH value to 11, stirring and reacting for 5 hours at the temperature of 80 ℃ to obtain a modified lignin blank, dialyzing the modified lignin blank for 8 hours by using a dialysis bag with the molecular weight cutoff of 1000, and freeze-drying to obtain the modified lignin;
(2) mixing the modified lignin obtained in the step (1) with hollow titanium dioxide according to a mass ratio of 4: 1, mixing the raw materials in water with the mass of 10 times that of the modified lignin, stirring and mixing the raw materials, filtering the mixture to obtain a modified titanium dioxide blank, and drying the modified titanium dioxide blank for 2 hours at the temperature of 85 ℃ to obtain modified titanium dioxide;
(3) mixing bacterial cellulose and acetone according to a mass ratio of 1: 40, mixing the mixture in a flask, adding maleic anhydride with the mass of 0.2 time that of the bacterial cellulose and diisopropylamine with the mass of 0.15 time that of the bacterial cellulose into the flask, stirring the mixture for reaction for 45 hours at room temperature, filtering the mixture to obtain a modified cellulose blank, and washing the modified cellulose blank with absolute ethyl alcohol for 4 times to obtain modified cellulose;
(4) mixing the modified cellulose obtained in the step (3) with 12% ammonia water according to a mass ratio of 1: 10 to obtain a modified cellulose mixed dispersion liquid, and mixing the modified titanium dioxide obtained in the step (2) with water according to a mass ratio of 1: 55, adding ammonium persulfate which is 0.7 time of the mass of the modified titanium dioxide into the reaction kettle, stirring and mixing, then adding modified cellulose mixed dispersion liquid which is 80 times of the mass of the modified titanium dioxide into the reaction kettle in a dropwise manner at the speed of 35 drops/min, stirring and reacting for 12 hours at the temperature of 40 ℃ and the rotating speed of 400r/min, then adding epoxy chloropropane which is 0.4 time of the mass of the modified titanium dioxide into the reaction, stirring and reacting for 3 hours at the temperature of 45 ℃, freeze-drying and crushing to obtain a mixed additive blank;
(5) mixing the mixed additive blank obtained in the step (4) with the chitosan quaternary ammonium salt solution according to the mass ratio of 1: 10, mixing the mixture in a three-neck flask, adding anthranilic acid with the mass 1.5 times that of a mixed additive blank into the three-neck flask, stirring and mixing, adding oxidized glucan with the mass 0.3 times that of the mixed additive blank into the three-neck flask, stirring and reacting for 3 hours at the temperature of 60 ℃, filtering to obtain a pretreated mixed additive blank, adding the pretreated mixed additive blank and hexadecyl trimethoxy siloxane into a hydrothermal kettle, wherein the hexadecyl trimethoxy siloxane is not in contact with the pretreated additive blank, and performing hydrothermal treatment for 2 hours at the temperature of 110 ℃ to obtain a mixed additive;
(6) weighing the following components in parts by weight: 80 parts of polybutylene adipate-terephthalate and 20 parts of mixed additive, mixing the polybutylene adipate-terephthalate and dichloromethane in a stirrer, adding the mixed additive, stirring and mixing to obtain a coating liquid, coating the coating liquid for 3 times, controlling the interval between every two coatings for 15s, uncovering the coatings, and drying for 2 hours at the temperature of 70 ℃ to obtain the degradable heat-preservation plastic mulching film.
Optimally, the preparation method of the hollow titanium dioxide in the step (2) comprises the following steps of mixing the crosslinked polystyrene microspheres with the mixed acid liquor according to the mass ratio of 1: 80, stirring for reaction, filtering, washing until the washing liquid is neutral to obtain the nitrated polystyrene microsphere, wherein the nitrated polystyrene microsphere comprises the following components in percentage by mass: 12% of sodium hydroxide solution according to the mass ratio of 1: 15, adding potassium persulfate which is 0.3 time of the mass of the nitrated polystyrene microsphere, stirring for reaction, and filtering to obtain an aminated polystyrene microsphere; mixing aminated polystyrene microspheres with an ethanol solution with the mass fraction of 80% according to the mass ratio of 1: 50, adding glacial acetic acid with the mass 3 times that of the aminated polystyrene microsphere, stirring and mixing, then dripping a tetrabutyl titanate ethanol solution with the mass fraction of 40% at the speed of 55 drops/min, stirring and reacting for 2 hours at the temperature of 40 ℃, filtering to obtain microspheres, calcining the microspheres for 2 hours at the temperature of 500 ℃, and discharging to obtain the hollow titanium dioxide.
Comparative example
A degradable thermal insulation plastic mulching film mainly comprises the following components in parts by weight: 80 parts of polybutylene adipate terephthalate and 20 parts of mixed additives.
A preparation method of a degradable heat-preservation plastic mulching film mainly comprises the following preparation steps:
(1) mixing lignin and hollow titanium dioxide according to a mass ratio of 4: 1, mixing the raw materials in water with the mass of 10 times that of the modified lignin, stirring and mixing the raw materials, filtering the mixture to obtain a modified titanium dioxide blank, and drying the modified titanium dioxide blank for 2 hours at the temperature of 85 ℃ to obtain modified titanium dioxide;
(2) mixing bacterial cellulose and 12% ammonia water in a mass ratio of 1: 10 to obtain a bacterial cellulose mixed dispersion liquid, and mixing the modified titanium dioxide obtained in the step (1) with water according to a mass ratio of 1: 55, adding ammonium persulfate which is 0.7 time of the mass of the modified titanium dioxide into the reaction kettle, stirring and mixing, then adding bacterial cellulose mixed dispersion liquid which is 80 times of the mass of the modified titanium dioxide into the reaction kettle in a dropwise manner at the speed of 35 drops/min, stirring and reacting for 12 hours at the temperature of 40 ℃ and the rotating speed of 400r/min, then adding epoxy chloropropane which is 0.4 time of the mass of the modified titanium dioxide into the reaction, stirring and reacting for 3 hours at the temperature of 45 ℃, and then freeze-drying and crushing to obtain a mixed additive blank;
(3) mixing the mixed additive blank obtained in the step (2) with the chitosan quaternary ammonium salt solution according to the mass ratio of 1: 10, mixing the mixture in a three-neck flask, adding anthranilic acid with the mass 1.5 times that of a mixed additive blank into the three-neck flask, stirring and mixing, adding oxidized glucan with the mass 0.3 times that of the mixed additive blank into the three-neck flask, stirring and reacting for 3 hours at the temperature of 60 ℃, filtering to obtain a pretreated mixed additive blank, adding the pretreated mixed additive blank and hexadecyl trimethoxy siloxane into a hydrothermal kettle, wherein the hexadecyl trimethoxy siloxane is not in contact with the pretreated additive blank, and performing hydrothermal treatment for 2 hours at the temperature of 110 ℃ to obtain a mixed additive;
(4) weighing the following components in parts by weight: 80 parts of polybutylene adipate-terephthalate and 20 parts of mixed additive, mixing the polybutylene adipate-terephthalate and dichloromethane in a stirrer, adding the mixed additive, stirring and mixing to obtain a coating liquid, coating the coating liquid for 3 times, controlling the interval between every two coatings for 15s, uncovering the coatings, and drying for 2 hours at the temperature of 70 ℃ to obtain the degradable heat-preservation plastic mulching film.
As an optimization, the preparation method of the hollow titanium dioxide in the step (1) comprises the following steps of mixing the crosslinked polystyrene microspheres with the mixed acid solution according to a mass ratio of 1: 80, stirring for reaction, filtering, washing until the washing liquid is neutral to obtain the nitrated polystyrene microsphere, wherein the nitrated polystyrene microsphere comprises the following components in percentage by mass: 12% of sodium hydroxide solution according to the mass ratio of 1: 15, adding potassium persulfate which is 0.3 time of the mass of the nitrated polystyrene microsphere, stirring for reaction, and filtering to obtain an aminated polystyrene microsphere; mixing aminated polystyrene microspheres with an ethanol solution with the mass fraction of 80% according to the mass ratio of 1: 50, adding glacial acetic acid with the mass 3 times that of the aminated polystyrene microsphere, stirring and mixing, then dripping a tetrabutyl titanate ethanol solution with the mass fraction of 40% at the speed of 55 drops/min, stirring and reacting for 2 hours at the temperature of 40 ℃, filtering to obtain microspheres, calcining the microspheres for 2 hours at the temperature of 500 ℃, and discharging to obtain the hollow titanium dioxide.
Examples of effects
The following table 1 shows the results of performance analysis of the degradable thermal insulation plastic mulching films using examples 1 to 4 of the present invention and comparative examples.
TABLE 1
From the comparison of the experimental data of example 1 and comparative example 1 in table 1, it can be found that the mechanical property and the heat preservation property of the product can be effectively improved by adding the mixed additive when the degradable heat preservation plastic mulching film is prepared, and the degradation efficiency of the product after the garlic is mature can be effectively improved.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.