CN113150423A - High-temperature-resistant and low-temperature-resistant impact-resistant polyethylene plastic and preparation method thereof - Google Patents
High-temperature-resistant and low-temperature-resistant impact-resistant polyethylene plastic and preparation method thereof Download PDFInfo
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Abstract
The invention discloses high-low temperature resistant and impact resistant polyethylene plastic and a preparation method thereof, and relates to the technical field of new materials. Mixing titanic acid and dihexylamine, performing microwave reaction to prepare alkylated tetratitanic acid, then mixing magnetic silicon dioxide microspheres and carboxyethyl silanetriol sodium salt for reaction to prepare modified silicon dioxide, mixing the modified silicon dioxide and the alkylated tetratitanic acid for reaction to prepare modified tetratitanic acid, then mixing the modified tetratitanic acid and composite polylactic acid prepared from polylactic acid and polycaprolactone, pressing, crushing, sieving, performing magnetic sieving to prepare mixed polylactic acid, performing alkali etching on the mixed polylactic acid to prepare modified polylactic acid, mixing the modified polylactic acid and ultrahigh molecular weight polyethylene, and performing injection molding to prepare the high-low temperature impact resistant polyethylene plastic. The high-temperature and low-temperature resistant impact-resistant polyethylene plastic prepared by the invention has better strength, high-temperature and low-temperature resistance and better frost crack resistance.
Description
Technical Field
The invention relates to the technical field of new materials, in particular to high-low temperature impact resistant polyethylene plastic and a preparation method thereof.
Background
Polyethylene is polymerized from ethylene monomers, and endows polyethylene materials with excellent physicochemical properties, such as: mechanical strength, low oxygen permeability, low water vapor permeability, chemical corrosion resistance, yellowing resistance and the like. Polyethylene is widely applied to the fields of chemical lining protective films, chemical conveying pipelines, chemical reagent packaging bags, agricultural mulching films, sewage conveying pipelines and the like.
However, when polyethylene is used as a transportation pipe, the polyethylene is often exposed to the external environment, which requires the polyethylene to have better impact resistance; meanwhile, when polyethylene is used as a water delivery pipe, the polyethylene has poor heat insulation performance in winter, so that water in the pipeline can expand when being frozen, and the polyethylene pipe is burst, and therefore, the polyethylene pipe is required to have better strength and certain elasticity.
Disclosure of Invention
The invention aims to provide a high-temperature-resistant and low-temperature-resistant impact-resistant polyethylene plastic and a preparation method thereof, and aims to solve the problems in the prior art.
The high-temperature-resistant and impact-resistant polyethylene plastic is characterized by mainly comprising the following raw material components in parts by weight: 60-80 parts of ultrahigh molecular weight polyethylene, 8-15 parts of composite polylactic acid, 8-15 parts of modified silicon dioxide and 8-12 parts of alkylated tetratitanic acid;
the modified silicon dioxide is prepared by processing magnetic silicon dioxide microspheres with carboxyethyl silane triol sodium salt.
Preferably, the ultra-high molecular weight polyethylene is a polyethylene mixture with an average molecular weight of more than 150 ten thousand.
As optimization, the composite polylactic acid is formed by mixing polycaprolactone, polylactic acid and a solubilizer; the solubilizer is tributyl citrate.
Preferably, the alkylated tetratitanic acid is prepared by acidifying potassium tetratitanate and then treating the acidified potassium tetratitanate and dihexylamine under the microwave condition and then performing ultrasonic dispersion on the acidified potassium tetratitanate and the dihexylamine.
As optimization, the high-temperature resistant, low-temperature resistant and impact resistant polyethylene plastic mainly comprises the following raw material components in parts by weight: 74 parts of ultrahigh molecular weight polyethylene, 10 parts of composite polylactic acid, 8 parts of modified silicon dioxide and 8 parts of alkylated tetratitanic acid.
The preparation method of the high-temperature-resistant and low-temperature-resistant impact-resistant polyethylene plastic mainly comprises the following preparation steps:
(1) mixing potassium tetratitanate and hydrochloric acid, reacting under the microwave condition, performing centrifugal separation to obtain tetratitanic acid, mixing the tetratitanic acid and a dihexylamine ethanol solution, reacting under the microwave condition, performing ultrasonic dispersion, filtering, and washing to obtain alkylated tetratitanic acid;
(2) mixing the magnetic silica microspheres with an ethanol solution, adding carboxyethyl silanetriol sodium salt, stirring and mixing, filtering, and drying to obtain modified silica;
(3) mixing the alkylated tetratitanic acid obtained in the step (1) with water, adding the modified silicon dioxide obtained in the step (2) and a catalyst, stirring for reaction, filtering, and drying to obtain modified tetratitanic acid;
(4) mixing polylactic acid and polycaprolactone, adding a solubilizer, performing melt extrusion, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate with the modified titanic acid obtained in the step (3), performing melt extrusion, granulating to obtain a mixed polylactic acid blank, drying, pressing, crushing, sieving, screening by using an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, etching the mixed polylactic acid in alkali liquor, filtering, washing and drying to obtain the modified polylactic acid;
(5) and (4) mixing and grinding the modified polylactic acid obtained in the step (4) and the ultra-high molecular weight polyethylene to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
As optimization, the preparation method of the high-temperature-resistant and low-temperature-resistant impact-resistant polyethylene plastic mainly comprises the following preparation steps:
(1) mixing potassium tetratitanate and hydrochloric acid with the concentration of 1.18-1.35 mol/L according to the mass ratio of 1: 10-1: 15, reacting for 60-90 min under the condition of microwave power of 400-420W, centrifugally separating for 5-12 min under the condition of rotating speed of 3000-4200 r/min, standing for 30min, removing supernatant, filtering the subnatant to obtain tetra-titanic acid, mixing the tetra-titanic acid and a dihexylamine ethanol solution with the mass fraction of 30-40% in a flask according to the mass ratio of 1: 10-1: 15, placing the flask in a microwave reactor, performing condensation reflux reaction for 1-3 h under the condition of power of 400-450W, performing ultrasonic dispersion on materials in the flask for 30-40 min under the condition of power of 45-55 kHz, filtering to obtain alkylated tetra-titanic acid blanks, washing the alkylated tetra-titanic acid blanks for 2-4 times by using absolute ethyl alcohol to obtain the alkylated tetra-titanic acid;
(2) mixing magnetic silica microspheres and 60-70% of ethanol solution according to the mass ratio of 1: 8-1: 12 in a beaker, adding carboxyethyl silanetriol sodium salt which is 2-4 times of the mass of the magnetic silica microspheres in the beaker, stirring and mixing, filtering to obtain a modified silica sheet blank, and drying the modified silica blank at 80 ℃ for 1-3 hours to obtain modified silica;
(3) mixing and mixing the alkylated tetratitanic acid obtained in the step (1) and water according to the mass ratio of 1: 15-1: 30, adding the modified silicon dioxide obtained in the step (2) and 4-dimethylaminopyridine which are 0.2-0.6 times of the mass of the alkylated tetratitanic acid and 0.1-0.3 times of the mass of the alkylated tetratitanic acid, stirring and reacting for 1-4 hours at the temperature of 40-60 ℃, filtering to obtain a modified tetratitanic acid blank, and drying the modified tetratitanic acid blank for 1-3 hours at the temperature of 65-85 ℃ to obtain the modified tetratitanic acid;
(4) mixing polylactic acid and polycaprolactone according to a mass ratio of 1:5, adding tributyl citrate with the mass of 0.1-0.3 time of that of the polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate according to a mass ratio of 20: 1-30: 1, adding the modified titanic acid obtained in the step (3) with the mass of 1.5-1.8 times of that of the composite polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain a mixed polylactic acid blank, drying the mixed polylactic acid blank at the temperature of 80-95 ℃ for 30-50 min, pressing in a flat-plate vulcanizer to prepare a sheet with the thickness of 0.5-1.0 mm, crushing the sheet, sieving with a 1-5 mesh sieve to obtain a mixed polylactic acid blank, screening the mixed polylactic acid blank with an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, placing the mixed polylactic acid in a sodium hydroxide solution with the concentration of 0.5-1.0 mol/L, and then etching for 10-30 min, filtering to obtain a modified polylactic acid blank, washing the modified polylactic acid blank with deionized water until the washing liquid is neutral, and drying for 1-3 h at the temperature of 80-90 ℃ to obtain modified polylactic acid;
(5) mixing the modified polylactic acid obtained in the step (4) with the ultra-high molecular weight polyethylene according to a mass ratio of 1: and 2.5-1: 3, mixing and grinding to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
Optimally, the preparation method of the potassium tetratitanate in the step (1) comprises the steps of mixing and grinding titanium dioxide and potassium carbonate according to the mass ratio of 3:1, sintering for 1 hour at 1000 ℃, and sintering for 30min at 800 ℃ to obtain the potassium tetratitanate.
Optimally, the preparation method of the magnetic silica microspheres in the step (2) comprises the steps of mixing nano ferroferric oxide with 60% by mass of ethanol aqueous solution according to the mass ratio of 1:300, performing ultrasonic dispersion to obtain ferroferric oxide dispersion, mixing the ferroferric oxide dispersion with tetraethoxysilane according to the volume ratio of 10: 1-30: 1, adding ammonia water with the mass fraction of 25-28% and the volume of 0.2-0.6 times that of the ferroferric oxide dispersion, performing stirring reaction, separating by using an external magnetic field, removing clear liquid, filtering to obtain magnetic silica microsphere blanks, and washing the magnetic silica microsphere blanks by using absolute ethyl alcohol and ultrapure water for 3 times to obtain the magnetic silica microspheres.
As optimization, the conditions of the melt extrusion in the step (4) are that the temperature of the double-screw extruder is set to 130 ℃, 140 ℃ and 140 ℃, and the rotating speed of the screw is 200 r/min.
Compared with the prior art, the invention has the beneficial effects that:
the invention adds modified polylactic acid prepared by modified silicon dioxide, alkylated tetratitanic acid and composite polylactic acid when preparing high-low temperature impact resistant polyethylene plastic.
Firstly, the alkylated tetratitanic acid is of a lamellar structure and can be used as a filler after being added into polyethylene, so that the bonding force among molecules in the polyethylene is improved, and the strength and the high-temperature resistance of a product are further improved; secondly, the raw material of the modified polylactic acid contains modified silicon dioxide, the silicon dioxide becomes magnetic microspheres with carboxyl on the outer side after modification, the existence of the carboxyl can react with polycaprolactone in the composite polylactic acid and amino on alkylated tetratitanic acid, so that the composite polylactic acid can be connected with the alkylated tetratitanic acid through the modified silicon dioxide, and the prepared mixed polylactic acid blank can be screened through the magnetism of the modified silicon dioxide, thereby ensuring that the modified polylactic acid added into polyethylene is a laminated structure of the alkylated tetratitanic acid and the composite polylactic acid; furthermore, as the modified polylactic acid is etched by the alkali liquor in the preparation process, pores can be formed between the composite polylactic acid and the alkylated tetratitanic acid, and meanwhile, as the composite polylactic acid has excellent shape memory performance, when the polyethylene is used in a water conveying pipe, the extrusion energy generated by the water solidification under the low-temperature condition on the polyethylene can be absorbed by the compression of the pores between the composite polylactic acid and the alkylated tetratitanic acid, so that the probability of the breakage of the polyethylene pipe in winter is reduced, and meanwhile, when the external temperature is increased, the pores between the composite polylactic acid and the alkylated tetratitanic acid are formed. Can reappear, thereby leading the product to have long-acting frost crack resistance when being used as a water delivery pipe.
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:
high temperature resistance: the Vicat softening points of the high-temperature and low-temperature impact resistant polyethylene plastics obtained in each example and the comparative product are tested according to GB/T1633, the load is 4kg, and the heating rate is 50 ℃/h.
Tensile property: the tensile breaking strength of the high and low temperature impact resistant polyethylene plastics obtained in each example and the comparative product was tested according to GB/T1040.
The frost cracking resistance is as follows: the high-temperature resistant and low-temperature resistant impact-resistant polyethylene plastics obtained in the embodiments and the comparative products are made into pipes with the same wall thickness of 3mm, after the pipes are filled with water, the two ends of the pipes are plugged, the water pipes filled with water are subjected to freeze-thaw circulation, and the required times of cracking of the measuring pipes are measured.
Example 1
A polyethylene plastic with high and low temperature resistance and impact resistance mainly comprises the following components in parts by weight: 74 parts of ultrahigh molecular weight polyethylene, 10 parts of composite polylactic acid, 8 parts of modified silicon dioxide and 8 parts of alkylated tetratitanic acid.
A preparation method of high-low temperature impact resistant polyethylene plastic mainly comprises the following preparation steps:
(1) mixing potassium tetratitanate and hydrochloric acid with the concentration of 1.20mol/L according to the mass ratio of 1:12, mixing, reacting for 65min under the condition of microwave power of 420W, centrifugally separating for 8min under the condition of 3500r/min, standing for 30min, removing supernatant, filtering the subnatant to obtain tetra-titanic acid, mixing the tetra-titanic acid and a dihexylamine ethanol solution with the mass fraction of 40% in a flask according to the mass ratio of 1:15, placing the flask in a microwave reactor, carrying out condensation reflux reaction for 2h under the condition of power of 420W, ultrasonically dispersing materials in the flask for 30min under the condition of power of 55kHz, filtering to obtain an alkylated tetra-titanic acid blank, washing the alkylated tetra-titanic acid blank with absolute ethyl alcohol for 3 times to obtain alkylated tetra-titanic acid;
(2) mixing magnetic silica microspheres and 65% ethanol solution in a mass ratio of 1:10 in a beaker, adding carboxyethyl silanetriol sodium salt which is 3 times of the mass of the magnetic silica microspheres into the beaker, stirring and mixing, filtering to obtain a modified silica sheet blank, and drying the modified silica blank at the temperature of 80 ℃ for 2 hours to obtain modified silica;
(3) mixing and mixing the alkylated tetratitanic acid obtained in the step (1) and water according to the mass ratio of 1:20, adding the modified silicon dioxide obtained in the step (2) and 4-dimethylaminopyridine which are 0.4 times of the mass of the alkylated tetratitanic acid, stirring and reacting for 3 hours at the temperature of 50 ℃, filtering to obtain a modified tetratitanic acid blank, and drying the modified tetratitanic acid blank for 2 hours at the temperature of 70 ℃ to obtain the modified tetratitanic acid;
(4) mixing polylactic acid and polycaprolactone according to a mass ratio of 1:5, adding tributyl citrate with the mass of 0.2 time of that of the polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate according to a mass ratio of 22:1, adding the modified titanic acid obtained in the step (3) with the mass of 1.6 times of that of the composite polylactic acid, performing melt extrusion in the double-screw extruder, granulating to obtain a mixed polylactic acid blank, drying the mixed polylactic acid blank at 90 ℃ for 40min, pressing in a flat plate vulcanizer to prepare a sheet with the thickness of 1mm, crushing the sheet, sieving with a 5-mesh sieve to obtain a mixed polylactic acid blank, screening the mixed polylactic acid blank by using an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, etching the mixed polylactic acid in a sodium hydroxide solution with the concentration of 0.8mol/L for 30min, filtering to obtain a modified polylactic acid blank, washing the modified polylactic acid blank with deionized water until the washing liquid is neutral, and drying for 2 hours at the temperature of 82 ℃ to obtain modified polylactic acid;
(5) mixing the modified polylactic acid obtained in the step (4) with the ultra-high molecular weight polyethylene according to a mass ratio of 1: 2.8 mixing and grinding to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
Optimally, the preparation method of the potassium tetratitanate in the step (1) comprises the steps of mixing and grinding titanium dioxide and potassium carbonate according to the mass ratio of 3:1, sintering for 1 hour at 1000 ℃, and sintering for 30min at 800 ℃ to obtain the potassium tetratitanate.
Optimally, the preparation method of the magnetic silica microspheres in the step (2) comprises the steps of mixing nano ferroferric oxide with 60% by mass of ethanol aqueous solution according to the mass ratio of 1:300, performing ultrasonic dispersion to obtain ferroferric oxide dispersion, mixing the ferroferric oxide dispersion with tetraethoxysilane according to the volume ratio of 25:1, adding 26% by mass of ammonia water which is 0.4 times of the volume of the ferroferric oxide dispersion, stirring for reaction, separating by using an external magnetic field, removing clear liquid, filtering to obtain magnetic silica microsphere blanks, and washing the magnetic silica microsphere blanks by using absolute ethyl alcohol and ultrapure water for 3 times respectively to obtain the magnetic silica microspheres.
As optimization, the conditions of the melt extrusion in the step (4) are that the temperature of the double-screw extruder is set to 130 ℃, 140 ℃ and 140 ℃, and the rotating speed of the screw is 200 r/min.
Example 2
A polyethylene plastic with high and low temperature resistance and impact resistance mainly comprises the following components in parts by weight: 74 parts of ultrahigh molecular weight polyethylene, 10 parts of composite polylactic acid, 8 parts of silicon dioxide and 8 parts of alkylated tetratitanic acid.
A preparation method of high-low temperature impact resistant polyethylene plastic mainly comprises the following preparation steps:
(1) mixing potassium tetratitanate and hydrochloric acid with the concentration of 1.20mol/L according to the mass ratio of 1:12, mixing, reacting for 65min under the condition of microwave power of 420W, centrifugally separating for 8min under the condition of 3500r/min, standing for 30min, removing supernatant, filtering the subnatant to obtain tetra-titanic acid, mixing the tetra-titanic acid and a dihexylamine ethanol solution with the mass fraction of 40% in a flask according to the mass ratio of 1:15, placing the flask in a microwave reactor, carrying out condensation reflux reaction for 2h under the condition of power of 420W, ultrasonically dispersing materials in the flask for 30min under the condition of power of 55kHz, filtering to obtain an alkylated tetra-titanic acid blank, washing the alkylated tetra-titanic acid blank with absolute ethyl alcohol for 3 times to obtain alkylated tetra-titanic acid;
(2) mixing the alkylated tetratitanic acid obtained in the step (1) with water according to a mass ratio of 1:20, adding magnetic silica microspheres with the mass of 0.4 time that of the alkylated tetratitanic acid and 4-dimethylaminopyridine with the mass of 0.2 time that of the alkylated tetratitanic acid, stirring and reacting for 3 hours at the temperature of 50 ℃, filtering to obtain a modified tetratitanic acid blank, and drying the modified tetratitanic acid blank for 2 hours at the temperature of 70 ℃ to obtain the modified tetratitanic acid;
(3) mixing polylactic acid and polycaprolactone according to a mass ratio of 1:5, adding tributyl citrate with the mass of 0.2 time of that of the polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate according to a mass ratio of 22:1, adding the modified titanic acid obtained in the step (2) with the mass of 1.6 times of that of the composite polylactic acid, performing melt extrusion in the double-screw extruder, granulating to obtain a mixed polylactic acid blank, drying the mixed polylactic acid blank at 90 ℃ for 40min, pressing the mixed polylactic acid blank in a flat plate vulcanizer to prepare a sheet with the thickness of 1mm, crushing the sheet, sieving with a 5-mesh sieve to obtain a mixed polylactic acid blank, screening the mixed polylactic acid blank by using an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, etching the mixed polylactic acid in a sodium hydroxide solution with the concentration of 0.8mol/L for 30min, filtering to obtain a modified polylactic acid blank, washing the modified polylactic acid blank with deionized water until the washing liquid is neutral, and drying for 2 hours at the temperature of 82 ℃ to obtain modified polylactic acid;
(4) mixing the modified polylactic acid obtained in the step (3) and the ultra-high molecular weight polyethylene according to the mass ratio of 1: 2.8 mixing and grinding to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
Optimally, the preparation method of the potassium tetratitanate in the step (1) comprises the steps of mixing and grinding titanium dioxide and potassium carbonate according to the mass ratio of 3:1, sintering for 1 hour at 1000 ℃, and sintering for 30min at 800 ℃ to obtain the potassium tetratitanate.
Optimally, the preparation method of the magnetic silica microspheres in the step (2) comprises the steps of mixing nano ferroferric oxide with 60% by mass of ethanol aqueous solution according to the mass ratio of 1:300, performing ultrasonic dispersion to obtain ferroferric oxide dispersion, mixing the ferroferric oxide dispersion with tetraethoxysilane according to the volume ratio of 25:1, adding 26% by mass of ammonia water which is 0.4 times of the volume of the ferroferric oxide dispersion, stirring for reaction, separating by using an external magnetic field, removing clear liquid, filtering to obtain magnetic silica microsphere blanks, and washing the magnetic silica microsphere blanks by using absolute ethyl alcohol and ultrapure water for 3 times respectively to obtain the magnetic silica microspheres.
As optimization, the conditions of the melt extrusion in the step (3) are that the temperature of the double-screw extruder is set to 130 ℃, 140 ℃ and 140 ℃, and the rotating speed of the screw is 200 r/min.
Example 3
A polyethylene plastic with high and low temperature resistance and impact resistance mainly comprises the following components in parts by weight: 74 parts of ultrahigh molecular weight polyethylene, 10 parts of composite polylactic acid, 8 parts of modified silicon dioxide and 8 parts of tetratitanic acid.
A preparation method of high-low temperature impact resistant polyethylene plastic mainly comprises the following preparation steps:
(1) mixing potassium tetratitanate and hydrochloric acid with the concentration of 1.20mol/L according to the mass ratio of 1:12, mixing, reacting for 65min under the condition of microwave power of 420W, centrifugally separating for 8min under the condition of the rotating speed of 3500r/min, standing for 30min, removing supernatant, and filtering the subnatant to obtain titanic acid;
(2) mixing magnetic silica microspheres and 65% ethanol solution in a mass ratio of 1:10 in a beaker, adding carboxyethyl silanetriol sodium salt which is 3 times of the mass of the magnetic silica microspheres into the beaker, stirring and mixing, filtering to obtain a modified silica sheet blank, and drying the modified silica blank at the temperature of 80 ℃ for 2 hours to obtain modified silica;
(3) mixing the titanic acid obtained in the step (1) and water according to a mass ratio of 1:20, adding the modified silicon dioxide obtained in the step (2) with the mass of 0.4 time of that of the titanic acid and 4-dimethylamino pyridine with the mass of 0.2 time of that of the titanic acid, stirring and reacting for 3 hours at the temperature of 50 ℃, filtering to obtain a modified titanic acid blank, and drying the modified titanic acid blank for 2 hours at the temperature of 70 ℃ to obtain the modified titanic acid;
(4) mixing polylactic acid and polycaprolactone according to a mass ratio of 1:5, adding tributyl citrate with the mass of 0.2 time of that of the polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate according to a mass ratio of 22:1, adding the modified titanic acid obtained in the step (3) with the mass of 1.6 times of that of the composite polylactic acid, performing melt extrusion in the double-screw extruder, granulating to obtain a mixed polylactic acid blank, drying the mixed polylactic acid blank at 90 ℃ for 40min, pressing in a flat plate vulcanizer to prepare a sheet with the thickness of 1mm, crushing the sheet, sieving with a 5-mesh sieve to obtain a mixed polylactic acid blank, screening the mixed polylactic acid blank by using an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, etching the mixed polylactic acid in a sodium hydroxide solution with the concentration of 0.8mol/L for 30min, filtering to obtain a modified polylactic acid blank, washing the modified polylactic acid blank with deionized water until the washing liquid is neutral, and drying for 2 hours at the temperature of 82 ℃ to obtain modified polylactic acid;
(5) mixing the modified polylactic acid obtained in the step (4) with the ultra-high molecular weight polyethylene according to a mass ratio of 1: 2.8 mixing and grinding to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
Optimally, the preparation method of the potassium tetratitanate in the step (1) comprises the steps of mixing and grinding titanium dioxide and potassium carbonate according to the mass ratio of 3:1, sintering for 1 hour at 1000 ℃, and sintering for 30min at 800 ℃ to obtain the potassium tetratitanate.
Optimally, the preparation method of the magnetic silica microspheres in the step (2) comprises the steps of mixing nano ferroferric oxide with 60% by mass of ethanol aqueous solution according to the mass ratio of 1:300, performing ultrasonic dispersion to obtain ferroferric oxide dispersion, mixing the ferroferric oxide dispersion with tetraethoxysilane according to the volume ratio of 25:1, adding 26% by mass of ammonia water which is 0.4 times of the volume of the ferroferric oxide dispersion, stirring for reaction, separating by using an external magnetic field, removing clear liquid, filtering to obtain magnetic silica microsphere blanks, and washing the magnetic silica microsphere blanks by using absolute ethyl alcohol and ultrapure water for 3 times respectively to obtain the magnetic silica microspheres.
As optimization, the conditions of the melt extrusion in the step (4) are that the temperature of the double-screw extruder is set to 130 ℃, 140 ℃ and 140 ℃, and the rotating speed of the screw is 200 r/min.
Comparative example
A polyethylene plastic with high and low temperature resistance and impact resistance mainly comprises the following components in parts by weight: 74 parts of ultrahigh molecular weight polyethylene, 10 parts of composite polylactic acid, 8 parts of silicon dioxide and 8 parts of tetratitanic acid.
A preparation method of high-low temperature impact resistant polyethylene plastic mainly comprises the following preparation steps:
(1) mixing potassium tetratitanate and hydrochloric acid with the concentration of 1.20mol/L according to the mass ratio of 1:12, mixing, reacting for 65min under the condition of microwave power of 420W, centrifugally separating for 8min under the condition of the rotating speed of 3500r/min, standing for 30min, removing supernatant, and filtering the subnatant to obtain titanic acid;
(2) mixing the titanic acid obtained in the step (1) and water according to a mass ratio of 1:20, adding magnetic silica microspheres with a mass of 0.4 time that of the titanic acid and 4-dimethylaminopyridine with a mass of 0.2 time that of the titanic acid, stirring and reacting for 3 hours at a temperature of 50 ℃, filtering to obtain a modified titanic acid blank, and drying the modified titanic acid blank for 2 hours at a temperature of 70 ℃ to obtain modified titanic acid;
(3) mixing polylactic acid and polycaprolactone according to a mass ratio of 1:5, adding tributyl citrate with the mass of 0.2 time of that of the polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate according to a mass ratio of 22:1, adding the modified titanic acid obtained in the step (2) with the mass of 1.6 times of that of the composite polylactic acid, performing melt extrusion in the double-screw extruder, granulating to obtain a mixed polylactic acid blank, drying the mixed polylactic acid blank at 90 ℃ for 40min, pressing the mixed polylactic acid blank in a flat plate vulcanizer to prepare a sheet with the thickness of 1mm, crushing the sheet, sieving with a 5-mesh sieve to obtain a mixed polylactic acid blank, screening the mixed polylactic acid blank by using an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, etching the mixed polylactic acid in a sodium hydroxide solution with the concentration of 0.8mol/L for 30min, filtering to obtain a modified polylactic acid blank, washing the modified polylactic acid blank with deionized water until the washing liquid is neutral, and drying for 2 hours at the temperature of 82 ℃ to obtain modified polylactic acid;
(4) mixing the modified polylactic acid obtained in the step (3) and the ultra-high molecular weight polyethylene according to the mass ratio of 1: 2.8 mixing and grinding to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
Optimally, the preparation method of the potassium tetratitanate in the step (1) comprises the steps of mixing and grinding titanium dioxide and potassium carbonate according to the mass ratio of 3:1, sintering for 1 hour at 1000 ℃, and sintering for 30min at 800 ℃ to obtain the potassium tetratitanate.
Optimally, the preparation method of the magnetic silica microspheres in the step (2) comprises the steps of mixing nano ferroferric oxide with 60% by mass of ethanol aqueous solution according to the mass ratio of 1:300, performing ultrasonic dispersion to obtain ferroferric oxide dispersion, mixing the ferroferric oxide dispersion with tetraethoxysilane according to the volume ratio of 25:1, adding 26% by mass of ammonia water which is 0.4 times of the volume of the ferroferric oxide dispersion, stirring for reaction, separating by using an external magnetic field, removing clear liquid, filtering to obtain magnetic silica microsphere blanks, and washing the magnetic silica microsphere blanks by using absolute ethyl alcohol and ultrapure water for 3 times respectively to obtain the magnetic silica microspheres.
As optimization, the conditions of the melt extrusion in the step (3) are that the temperature of the double-screw extruder is set to 130 ℃, 140 ℃ and 140 ℃, and the rotating speed of the screw is 200 r/min.
Examples of effects
The following table 1 shows the results of the performance analysis of the high and low temperature impact resistant polyethylene plastics using examples 1 to 4 of the present invention and comparative example.
TABLE 1
Compared with the experimental data of the example 1 and the comparative example 1 in the table 1, it can be found that the high and low temperature resistance and the strength of the product can be effectively improved by adding the modified polylactic acid in the preparation of the high and low temperature impact resistant polyethylene plastic, and the occurrence of the cracking phenomenon of the product when the product is used for a water pipe can be reduced; from the comparison of the experimental data of example 1 and examples 2 and 3, it can be found that when the magnetic silica microspheres are not modified or the tetra-titanic acid is not alkylated during the preparation of the modified polylactic acid, the alkylated tetra-titanic acid and the composite polylactic acid cannot form effective connection, so that after the silica is removed, voids cannot be reserved in the product added, and the product performance is affected.
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.
Claims (10)
1. The high-temperature-resistant and impact-resistant polyethylene plastic is characterized by mainly comprising the following raw material components in parts by weight: 60-80 parts of ultrahigh molecular weight polyethylene, 8-15 parts of composite polylactic acid, 8-15 parts of modified silicon dioxide and 8-12 parts of alkylated tetratitanic acid;
the modified silicon dioxide is prepared by processing magnetic silicon dioxide microspheres with carboxyethyl silane triol sodium salt.
2. The high and low temperature impact resistant polyethylene plastic according to claim 1, wherein the ultra-high molecular weight polyethylene is a mixture of polyethylene with an average molecular weight of 150 ten thousand or more.
3. The high and low temperature impact resistant polyethylene plastic according to claim 2, wherein the composite polylactic acid is formed by mixing polycaprolactone, polylactic acid and a solubilizer; the solubilizer is tributyl citrate.
4. The high and low temperature impact resistant polyethylene plastic according to claim 3, wherein the alkylated tetratitanic acid is prepared by acidifying potassium tetratitanate, treating with dihexylamine under microwave condition, and performing ultrasonic dispersion.
5. The high and low temperature impact resistant polyethylene plastic according to claim 4, wherein the high and low temperature impact resistant polyethylene plastic mainly comprises the following raw material components in parts by weight: 74 parts of ultrahigh molecular weight polyethylene, 10 parts of composite polylactic acid, 8 parts of modified silicon dioxide and 8 parts of alkylated tetratitanic acid.
6. The preparation method of the high-temperature-resistant and low-temperature-resistant impact-resistant polyethylene plastic is characterized by mainly comprising the following preparation steps of:
(1) mixing potassium tetratitanate and hydrochloric acid, reacting under the microwave condition, performing centrifugal separation to obtain tetratitanic acid, mixing the tetratitanic acid and a dihexylamine ethanol solution, reacting under the microwave condition, performing ultrasonic dispersion, filtering, and washing to obtain alkylated tetratitanic acid;
(2) mixing the magnetic silica microspheres with an ethanol solution, adding carboxyethyl silanetriol sodium salt, stirring and mixing, filtering, and drying to obtain modified silica;
(3) mixing the alkylated tetratitanic acid obtained in the step (1) with water, adding the modified silicon dioxide obtained in the step (2) and a catalyst, stirring for reaction, filtering, and drying to obtain modified tetratitanic acid;
(4) mixing polylactic acid and polycaprolactone, adding a solubilizer, performing melt extrusion, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate with the modified titanic acid obtained in the step (3), performing melt extrusion, granulating to obtain a mixed polylactic acid blank, drying, pressing, crushing, sieving, screening by using an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, etching the mixed polylactic acid in alkali liquor, filtering, washing and drying to obtain the modified polylactic acid;
(5) and (4) mixing and grinding the modified polylactic acid obtained in the step (4) and the ultra-high molecular weight polyethylene to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
7. The method for preparing the high and low temperature impact resistant polyethylene plastic according to claim 6, wherein the method for preparing the high and low temperature impact resistant polyethylene plastic mainly comprises the following preparation steps:
(1) mixing potassium tetratitanate and hydrochloric acid with the concentration of 1.18-1.35 mol/L according to the mass ratio of 1: 10-1: 15, reacting for 60-90 min under the condition of microwave power of 400-420W, centrifugally separating for 5-12 min under the condition of rotating speed of 3000-4200 r/min, standing for 30min, removing supernatant, filtering the subnatant to obtain tetra-titanic acid, mixing the tetra-titanic acid and a dihexylamine ethanol solution with the mass fraction of 30-40% in a flask according to the mass ratio of 1: 10-1: 15, placing the flask in a microwave reactor, performing condensation reflux reaction for 1-3 h under the condition of power of 400-450W, performing ultrasonic dispersion on materials in the flask for 30-40 min under the condition of power of 45-55 kHz, filtering to obtain alkylated tetra-titanic acid blanks, washing the alkylated tetra-titanic acid blanks for 2-4 times by using absolute ethyl alcohol to obtain the alkylated tetra-titanic acid;
(2) mixing magnetic silica microspheres and 60-70% of ethanol solution according to the mass ratio of 1: 8-1: 12 in a beaker, adding carboxyethyl silanetriol sodium salt which is 2-4 times of the mass of the magnetic silica microspheres in the beaker, stirring and mixing, filtering to obtain a modified silica sheet blank, and drying the modified silica blank at 80 ℃ for 1-3 hours to obtain modified silica;
(3) mixing and mixing the alkylated tetratitanic acid obtained in the step (1) and water according to the mass ratio of 1: 15-1: 30, adding the modified silicon dioxide obtained in the step (2) and 4-dimethylaminopyridine which are 0.2-0.6 times of the mass of the alkylated tetratitanic acid and 0.1-0.3 times of the mass of the alkylated tetratitanic acid, stirring and reacting for 1-4 hours at the temperature of 40-60 ℃, filtering to obtain a modified tetratitanic acid blank, and drying the modified tetratitanic acid blank for 1-3 hours at the temperature of 65-85 ℃ to obtain the modified tetratitanic acid;
(4) mixing polylactic acid and polycaprolactone according to a mass ratio of 1:5, adding tributyl citrate with the mass of 0.1-0.3 time of that of the polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain composite polylactic acid, mixing the composite polylactic acid and stannous octoate according to a mass ratio of 20: 1-30: 1, adding the modified titanic acid obtained in the step (3) with the mass of 1.5-1.8 times of that of the composite polylactic acid, performing melt extrusion in a double-screw extruder, granulating to obtain a mixed polylactic acid blank, drying the mixed polylactic acid blank at the temperature of 80-95 ℃ for 30-50 min, pressing in a flat-plate vulcanizer to prepare a sheet with the thickness of 0.5-1.0 mm, crushing the sheet, sieving with a 1-5 mesh sieve to obtain a mixed polylactic acid blank, screening the mixed polylactic acid blank with an external magnetic field, removing nonmagnetic particles to obtain mixed polylactic acid, placing the mixed polylactic acid in a sodium hydroxide solution with the concentration of 0.5-1.0 mol/L, and then etching for 10-30 min, filtering to obtain a modified polylactic acid blank, washing the modified polylactic acid blank with deionized water until the washing liquid is neutral, and drying for 1-3 h at the temperature of 80-90 ℃ to obtain modified polylactic acid;
(5) mixing the modified polylactic acid obtained in the step (4) with the ultra-high molecular weight polyethylene according to a mass ratio of 1: and 2.5-1: 3, mixing and grinding to obtain a polyethylene mixture, and performing injection molding on the polyethylene mixture to obtain the high-temperature and low-temperature impact-resistant polyethylene plastic.
8. The preparation method of the high and low temperature impact resistant polyethylene plastic according to claim 7, wherein the potassium tetratitanate in the step (1) is prepared by mixing and grinding titanium dioxide and potassium carbonate according to the mass ratio of 3:1, sintering for 1h at 1000 ℃, and sintering for 30min at 800 ℃ to obtain potassium tetratitanate.
9. The preparation method of high-temperature-resistant and impact-resistant polyethylene plastic according to claim 7, wherein the preparation method of the magnetic silica microspheres in the step (2) comprises the steps of mixing nano ferroferric oxide with 60% by mass of an ethanol aqueous solution according to a mass ratio of 1:300, performing ultrasonic dispersion to obtain a ferroferric oxide dispersion liquid, mixing the ferroferric oxide dispersion liquid with ethyl orthosilicate according to a volume ratio of 10: 1-30: 1, adding ammonia water with a mass fraction of 25-28% which is 0.2-0.6 times of the volume of the ferroferric oxide dispersion liquid, performing stirring reaction, separating by using an external magnetic field, removing clear liquid, filtering to obtain magnetic silica microsphere blanks, washing the magnetic silica microsphere blanks by using absolute ethyl alcohol and ultrapure water for 3 times respectively, and obtaining the magnetic silica microspheres.
10. The method for preparing polyethylene plastic with high and low temperature impact resistance according to claim 7, wherein the conditions of the melt extrusion in the step (4) are that the temperature of the twin-screw extruder is set to 130 ℃, 140 ℃ and 140 ℃, and the screw rotation speed is 200 r/min.
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