CN115284478A

CN115284478A - Australia tea tree composite microsphere and preparation method of 3D printing composite material thereof

Info

Publication number: CN115284478A
Application number: CN202210244771.XA
Authority: CN
Inventors: 周武艺; 聂健良; 郑文旭; 董先明; 谷文亮; 肖海军
Original assignee: Shaoguan Feisheng New Material Co ltd; South China Agricultural University
Current assignee: Shaoguan Feisheng New Material Co ltd; South China Agricultural University
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2022-11-04

Abstract

The invention discloses Australian tea tree powder composite microspheres and a preparation method of a 3D printing composite material thereof, wherein the Australian tea tree powder composite microspheres comprise 65-90 parts by weight of polycaprolactone, 5-30 parts by weight of Australian tea tree powder composite microspheres, 0.1-1 part by weight of nano microcrystalline cellulose, 0.5-2 parts by weight of tributyl citrate, 0.2-2 parts by weight of diatomite powder and 0.1-2 parts by weight of calcium carbonate. The 3D printing composite material prepared by the invention has the advantages of excellent antibacterial rate, excellent curing molding efficiency, good extrusion smoothness, good mechanical property, no toxicity, harmlessness, environmental friendliness, natural biodegradation, full and reasonable utilization of waste residues of Australian tea trees and the like, low and reasonable economic cost, mature production process technology and high industrialization degree.

Description

Australia tea tree composite microsphere and preparation method of 3D printing composite material thereof

Technical Field

The invention belongs to the technical field of nano composite materials, and particularly relates to Australia tea tree composite microspheres and a preparation method of a 3D printing composite material of the Australia tea tree composite microspheres.

Background

With the continuous development, use and popularization of 3D printing technology, the concept of 3D printing has become less miraculous in people's life in recent years, people who use and experience are more and more, and the field of application is more and more extensive. Two types of common applications of 3D printing are mainly printers and printing pens, the printers can be divided into the forms of melt extrusion molding, photocuring molding, laser sintering molding, glue bonding molding and the like according to different application requirements, and a food printer, a biological printer, a three-dimensional engraving printer and the like also appear in succession; the printing pen is mainly divided into a high-temperature printing pen and a low-temperature printing pen, more and more people start to use the low-temperature printing pen along with the use of people, the low-temperature printing pen is more suitable for children of 5-15 years old due to low-temperature safety, and the use is more and more, but the main low-temperature material consumable materials on the market are mainly polycaprolactone or modified polycaprolactone, most of the low-temperature material consumable materials are raw materials without antibacterial property, or a small part of the low-temperature material consumable materials adopts metal ions such as silver ion antibacterial agents or inorganic salt antibacterial materials, or a small part of the low-temperature material consumable materials adopts quaternary ammonium salt and other chemical materials as the antibacterial property; the antibacterial materials in the above categories have relatively good antibacterial effect, but have certain toxicity, and have adverse effects on the health and growth development of users after long-time contact.

Chinese patent (patent number: CN 201910681825.7) discloses a melaleuca alternifolia (Australia tea tree) tree residue powder biological feed, which comprises the following components in percentage by weight: 25-54.95% of corn, 35-65% of Australia tea tree biological powder, 2% of cottonseed meal, 3% of peanut meal, 1.5% of calcium hydrophosphate, 0.9% of stone powder, 0.2% of salt, 0.5% of vitamin premix, 0.1% of choline chloride, 0.15% of lysine, 0.2% of methionine, 1% of Australia tea tree essential oil and 0.5% of hydrolat. The antibacterial property of the Australian tea tree powder and chitosan oligosaccharide composite microspheres is more in vitro antibacterial property, and the principle and introduction of the functions of the animal oral administration and production are completely different directions, so that no reference inspiration exists.

Chinese patent (patent number: CN 201911292273.7) discloses a hemp biological fertilizer based on Australia tea tree essential oil processing residues and a preparation method thereof, wherein the hemp biological fertilizer comprises the following components in parts by weight: 200-240 parts of Australia tea tree essential oil processing residues, 50-70 parts of decomposed substances, 10-15 parts of traditional Chinese medicine residues, 20-30 parts of peanut bran, 15-20 parts of furfural residues, 3-5 parts of coconut shell carbon, 8-12 parts of slow release agents, 0.04-0.07 part of biological bacteria agents and 0.01-0.02 part of trace elements, wherein part of raw materials are subjected to crushing, fermentation, mixing, ultraviolet irradiation sterilization treatment and the like, and are bagged to obtain a finished fertilizer which mainly aims at inhibiting bacteria, expelling worms, increasing yield, improving soil and the like. The Australian tea tree composite microspheres have the main function of antibiosis, and have great difference with the implementation mode of the application from the consumption of Australian tea tree powder or the preparation method of the Australian tea tree powder-chitosan oligosaccharide composite antibacterial microspheres, the main purpose and the application field are quite different, the Australian tea tree and essential oil thereof with antibacterial effect are well known by the technical personnel in the field, and the preparation method and the effect of the composite antibacterial agent microspheres basically cannot obtain substantial and useful inspiration from the introduction.

Disclosure of Invention

Aiming at the problems, the invention provides a Australia tea tree composite microsphere and a preparation method of a 3D printing composite material thereof.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a preparation method of Australia tea tree composite microspheres comprises the following steps:

(1) Cutting the Australia tea tree branches into particles or small sections, baking to dry, crushing, and sieving with a sieve of 1000 meshes or more to obtain Australia tea tree powder;

(2) Adding the obtained Australian tea tree powder into the modified solution, uniformly dispersing, performing ultrasonic treatment (10-20 min), stirring at 50-70 ℃ for reaction for 3-8h, keeping stirring, cooling to room temperature, filtering, washing, drying, refining, and sieving with a sieve of 600 meshes or more to obtain modified Australian tea tree powder;

wherein the weight ratio of the content of the modifier in the modifying solution to the Australia tea tree powder is 1: (1-10);

(3) Preparing an aqueous solution with the total concentration of polyvinyl alcohol and polyvinylpyrrolidone of 2.5-3.5wt%, wherein the weight ratio of polyvinyl alcohol to polyvinylpyrrolidone is (4-10): (1-5); preparing an aqueous solution with the chitosan oligosaccharide concentration of 1-2wt%, wherein the molecular weight of the chitosan oligosaccharide is 500-5000; then mixing the two aqueous solutions uniformly to obtain a mixed solution; wherein the weight ratio of the polyvinyl alcohol and polyvinylpyrrolidone aqueous solution to the chitosan oligosaccharide aqueous solution is (1-5): (1-10);

(4) Adding the modified Australian tea tree powder into the mixed solution, uniformly dispersing, preparing powder particles by a spray drying process, drying, refining, and sieving by a sieve of 400 meshes or more to obtain the Australian tea tree composite microspheres; wherein the weight ratio of the modified Australian tea tree powder to the mixed solution is 1: (10-100).

Preferably, the branches of the Australian tea trees are taken from autonomous county of Yao nationality of milk origin Yao city or Yao county of Shaoguan city, and are one or more than one of branches of Australian tea tree waste residues after extraction of essential oil (conventional steam distillation method) and branches of Australian tea trees without extraction of essential oil.

Preferably, the modifier solution is ethanol solution with the modifier concentration of 3-8wt%, and the pH value is adjusted to 8-9 by triethanolamine.

More preferably, the modifier is a composition of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, diethylenetriamine and ammonium dodecylbenzene sulfonate, wherein the mass ratio of the N- (2-aminoethyl) -3-aminopropyltrimethoxysilane to the diethylenetriamine to the ammonium dodecylbenzene sulfonate is (2-10): (0.1-0.5): (1-3).

Preferably, the spray drying process controls: the inlet temperature was 103 deg.C, the outlet temperature was 70 deg.C, and the frequency of the atomizer was between 20-40 Hz.

The Australian tea tree composite microsphere is used for preparing a 3D printing composite material, and the method comprises the following steps:

uniformly mixing 5-30 parts by weight of Australian tea tree composite microspheres, 0.1-1 part by weight of microcrystalline cellulose, 0.2-2 parts by weight of diatomite powder and 0.1-2 parts by weight of calcium carbonate to obtain mixed powder A for later use; adding 0.5-2 parts by weight of tributyl citrate into 65-90 parts by weight of polycaprolactone, uniformly mixing, adding the obtained mixed powder A, and continuously mixing until the mixture is uniform to obtain a mixture B;

adding the mixture B into a double-screw extruder for melting and mixing, extruding, cooling, granulating and drying to obtain polycaprolactone composite granules;

and (III) adding the obtained polycaprolactone composite granules into a single-screw extruder for melt extrusion, drawing, cooling, air-drying and collecting wires to obtain the Australian tea tree 3D printing composite material.

Preferably, the temperature of the twin-screw extruder is set as follows: the first zone is 60 ℃, the second zone is 65 ℃, the third zone is 71 ℃, the fourth zone is 68 ℃, the fifth zone is 65 ℃, the head zone is 63 ℃, the rotating speed of the twin-screw is 32 r/min, and the granulating speed is 12.4 r/min.

Preferably, the single screw temperature is set as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the rotating speed of the single screw is 25 r/min.

In the preparation method, various required pigments can be added and mixed according to the color requirement to prepare the required color and luster.

The technical scheme of the invention has the following technical characteristics and beneficial effects:

(1) The modified Australian tea tree powder has hydrophilic groups and lipophilic groups, and can better generate affinity with polyvinyl alcohol, polyvinylpyrrolidone and chitosan oligosaccharide in an aqueous solution, and the modified Australian tea tree powder is taken as a core, and the polyvinyl alcohol, the polyvinylpyrrolidone and the chitosan oligosaccharide are fused with each other and coated on the surface of the modified Australian tea tree powder in a membrane form, so that the modified Australian tea tree powder forms a unified organic composite whole and forms microspherical particles; the formation of the external surface film not only protects Australia tea tree powder, but also mainly protects partial active substances contained in the Australia tea tree powder, such as active essential oil, active colloid and the like, and active ingredients in the Australian tea tree powder and active groups in the chitosan oligosaccharide generate a certain synergistic effect, so that the effect of adding one to be more than two is achieved, and the effect is obviously improved compared with the effect of singly using the Australian tea tree powder or the chitosan oligosaccharide.

(2) The reagents or solvents adopted by the invention are relatively nontoxic substances, most of the reagents or solvents belong to natural substances, such as Australian tea tree powder, chitosan oligosaccharide, microcrystalline cellulose, diatomite and the like, and the antibacterial components do not contain heavy metals and other components, so that the printing wire is more environment-friendly and has sustainability compared with the existing antibacterial components on the market, such as silver ions, zinc ions, quaternary ammonium salts and the like, and the main polymer matrix material polycaprolactone is also a novel green material which is green, environment-friendly and biodegradable, and the prepared printing wire is suitable for being used in a 3D printing pen and is safer and more reliable compared with the existing products on the market.

(3) The Australia tea tree composite microspheres are prepared by adopting a spray drying process, and microsphere particles with higher uniformity and better composite effect can be obtained; the microcrystalline cellulose added into the matrix can be used as a nucleating agent, so that the crystallization rate of the matrix can be increased, a large number of microcrystalline areas are formed in the cooling process after the wire is extruded in use, and the material is rapidly cooled and solidified; the mechanical comprehensive performance of the material can be improved under certain conditions by adding the diatomite powder, and the solidification of the matrix material can be facilitated; the tributyl citrate is added, so that the tributyl citrate not only can play a role of a dispersing agent to uniformly disperse numerous micro-particles, but also can be used as a plasticizer to improve the processability of the composite material and reduce the melting temperature of the composite material, so that the wire can keep good fluency in the use process, and is a non-toxic and environment-friendly additive; the aim of adding the calcium carbonate powder is mainly to improve the overall whiteness of the printing wire or the composite material, so that the material can be more easily blended with richer colors, and has wider application fields.

(4) The Australian tea tree powder is used as an antibacterial and additive component, on one hand, the raw material has good antibacterial performance and is modified and compounded to obtain more excellent antibacterial performance, on the other hand, a scheme which can be well solved is provided for the treatment of waste residues after the extraction and processing of Australian tea tree essential oil, and compared with the treatment of certain simple composts and the like, the scheme provided by the invention can obtain higher commercial value and inherits the concept of green and environment protection, the waste residues are recycled in a more appropriate mode to realize the due value of the waste residues, and the printing material is also a green and environment-friendly material which can be naturally degraded, and can be used as a direct compost or a slow-release compost mode for recycling after being used; in addition, the preparation method and the technology for the 3D printing composite material are mature and stable, the preparation and production technology is simple and convenient to operate, the economic cost is reasonable and low, and the current market or future market prospect is considerable.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed in the embodiments will be briefly described below, and it should be apparent that the drawings in the following description are only some embodiments of the present invention.

FIG. 1 is a flow chart of the preparation process and the application process of the present invention.

FIG. 2 is an optical electron micrograph of Australian tea Tree powder of the present invention.

FIG. 3 is an optical electron microscope image of the Australian tea tree composite microsphere of the present invention.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations where mutually exclusive features or steps are mutually exclusive.

Any feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features. The materials used in the following examples are as follows, but the present invention is not limited thereto.

Australia tea tree composite microspheres: the preparation method comprises the following steps of (1) cutting the Australia tea tree branch and stem waste residue subjected to extraction and processing of essential oil into particles or small sections, baking the particles or the small sections until the particles or the small sections are dried, crushing the particles by a crusher, and screening the particles to obtain Australia tea tree powder with the particle size of 1000 meshes or more; (2) Adding a modifier into ethanol to prepare a modified solution with the concentration of 5wt%, adjusting the pH value to 8-9 by using triethanolamine, adding the Australian tea tree powder into the modified solution to be uniformly dispersed, firstly carrying out ultrasonic treatment for 15min, then stirring, wherein the modification time is 4h, the modification temperature is 60 ℃, keeping stirring, naturally cooling to room temperature, filtering, washing, drying and refining to obtain modified Australian tea tree powder with the particle size of 600 meshes or more; wherein the weight ratio of the modifier to the Australia tea tree powder is 1:5, the pH value of the modified solution is kept between 8 and 9, the modifier is a composition of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, diethylenetriamine and ammonium dodecylbenzene sulfonate, and the mass fraction ratio of the modifier to the modifier is 5:0.1:1; (3) Then, adding polyvinyl alcohol and polyvinylpyrrolidone into deionized water, heating to 70 ℃ in a water bath, stirring and dissolving to prepare a 3wt% polyvinyl alcohol-polyvinylpyrrolidone aqueous solution, wherein the weight ratio of the polyvinyl alcohol to the polyvinylpyrrolidone is 4:2; adding chitosan oligosaccharide into deionized water, heating to 60 deg.C in water bath, stirring for dissolving, and preparing into 1.5wt% chitosan oligosaccharide water solution, wherein the molecular weight of chitosan oligosaccharide is 500-5000; and adding a polyvinyl alcohol-polyvinylpyrrolidone aqueous solution into the chitosan oligosaccharide aqueous solution, and uniformly stirring to obtain a mixed solution, wherein the weight ratio of the two aqueous solutions is 1:2; (4) Finally, adding the modified Australia tea tree powder into the mixed solution, and stirring and dispersing the mixture until the mixture is uniform; preparing powder particles by adopting a spray dryer through a spray drying process, continuously drying in a 50 ℃ drying oven for 6 hours, refining and screening to obtain the Australian tea tree composite microspheres of 400 meshes or above, wherein the mass ratio of the modified Australian tea tree powder to the mixed solution is 1:30.

australia tea tree powder microspheres: the preparation method comprises the following steps of (1) cutting the Australia tea tree branches and trunks subjected to extraction and processing of essential oil into particles or small segments, baking the particles or the small segments until the particles or the small segments are dried, crushing the particles by a crusher, and screening to obtain Australia tea tree powder with the particle size of 1000 meshes or more; (2) Adding a modifier into ethanol to prepare a modified solution with the mass fraction of 5%, regulating the pH value to 8-9 by using triethanolamine, adding the Australian tea tree powder into the modified solution to be uniformly dispersed, carrying out ultrasonic treatment for 15min, stirring for 4h at the modification temperature of 60 ℃, keeping stirring, naturally cooling to room temperature, filtering, washing, drying and refining to obtain modified Australian tea tree powder with the particle size of 600 meshes or more; wherein the mass fraction ratio of the modifier to the Australia tea tree powder is 1:5, the pH value of the modified solution is kept at about 8, the modifier is a composition of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, diethylenetriamine and ammonium dodecylbenzene sulfonate, and the mass fraction ratio of the modifier is 5:0.1:1; (3) Then, adding polyvinyl alcohol and polyvinylpyrrolidone into deionized water, heating to 70 ℃ in a water bath, stirring and dissolving to prepare a 3% polyvinyl alcohol-polyvinylpyrrolidone aqueous solution with a mass fraction ratio of 4:2; dispersing calcium carbonate powder into deionized water to prepare a calcium carbonate mixed solution with the mass fraction of 1.5%; and then adding the polyvinyl alcohol-polyvinylpyrrolidone aqueous solution into the calcium carbonate mixed solution, and uniformly stirring to obtain a mixed solution, wherein the mass fraction ratio of the mixed solution is 1:2; (4) Finally, adding the modified Australian tea tree powder into a polyvinyl alcohol-polyvinyl pyrrolidone aqueous solution, and stirring and dispersing the modified Australian tea tree powder to be uniform; preparing powder particles by adopting a spray dryer through a spray drying process, continuously drying in a 50 ℃ drying oven for 6 hours, refining and screening to obtain the Australian tea tree composite microspheres of 400 meshes or above, wherein the mass ratio of the modified Australian tea tree powder to the mixed solution is 1:30.

chitosan microspheres: firstly, adding polyvinyl alcohol and polyvinylpyrrolidone into deionized water, heating the mixture to 70 ℃ in a water bath, stirring and dissolving the mixture to prepare a polyvinyl alcohol-polyvinylpyrrolidone aqueous solution with the mass fraction of 3%, wherein the mass fraction ratio of the polyvinyl alcohol to the polyvinylpyrrolidone is 4:2; adding chitosan oligosaccharide into deionized water, heating to 60 deg.C in water bath, stirring for dissolving, and preparing into 1.5% chitosan oligosaccharide water solution, wherein the molecular weight of chitosan oligosaccharide is 500-5000; and then adding the polyvinyl alcohol-polyvinylpyrrolidone aqueous solution into the chitosan oligosaccharide aqueous solution, and uniformly stirring to obtain a mixed solution, wherein the mass fraction ratio of the mixed solution is 1:2; finally, dispersing calcium carbonate powder into the mixed solution, and stirring and dispersing the calcium carbonate powder to be uniform; preparing powder particles by adopting a spray dryer through a spray drying process, continuously drying in a 50 ℃ drying oven for 6 hours, refining and screening to obtain the Australian tea tree composite microspheres with the granularity of 400 meshes or more, wherein the mass ratio of the calcium carbonate powder to the mixed solution is 1:30.

hemp stem powder: pulverizing hemp stalk with the same equipment as that for pulverizing Australia tea Tree, and refining to obtain powder with size of above 400 mesh.

The microcrystalline cellulose is microcrystalline cellulose with the size of 1000-2000 meshes.

Diatomite: diatomaceous earth with a size of 500-1000 mesh is used.

Calcium carbonate: calcium carbonate with the size of more than 1000 meshes is adopted.

Example 1

Fully mixing 5 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 90 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until uniform to obtain a mixture;

adding the mixture into a double-screw mixing extruder, melting, mixing, extruding, cooling, granulating, and drying the granules in a vacuum oven at 50 ℃ for 8 hours to obtain dried polycaprolactone composite granules; wherein the twin-screw temperature is set as follows: the first zone is 60 ℃, the second zone is 65 ℃, the third zone is 71 ℃, the fourth zone is 68 ℃, the fifth zone is 65 ℃, the head zone is 63 ℃, the double screw rotating speed is 32 r/min, and the grain cutting speed is 12.4 r/min;

finally, adding the dried polycaprolactone composite granules into a single-screw extruder for heating, melting and extruding, drawing, cooling, air-drying, and collecting wires to obtain the Australia tea tree 3D printing composite material; wherein, single screw rod temperature sets up as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the single screw rotation speed is 25 r/min.

Example 2

Fully mixing 10 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 85 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until the mixture is uniform to obtain a mixture;

adding the mixture into a double-screw mixing extruder, melting, mixing, extruding, cooling, granulating, and drying the granules in a vacuum oven at 50 ℃ for 8 hours to obtain a dried Australia tea tree 3D printing composite material; wherein the twin-screw temperature is set as follows: the first zone is 60 ℃, the second zone is 65 ℃, the third zone is 71 ℃, the fourth zone is 68 ℃, the fifth zone is 65 ℃, the head zone is 63 ℃, the rotating speed of the twin-screw is 32 r/min, and the granulating speed is 12.4 r/min;

finally, adding the dried polycaprolactone composite granules into a single-screw extruder for heating, melting and extruding, drawing, cooling, air-drying, and collecting wires to obtain polycaprolactone composite wires capable of being printed in 3D; wherein the single screw temperature is set as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the single screw rotation speed is 25 r/min.

Example 3

Firstly, fully mixing 15 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 80 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until the mixture is uniform to obtain a mixture;

finally, adding the dried polycaprolactone composite granules into a single-screw extruder for heating, melting and extruding, drawing, cooling, air-drying, and collecting wires to obtain the Australia tea tree 3D printing composite material; wherein, single screw rod temperature sets up as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the rotating speed of the single screw is 25 r/min.

Example 4

Fully mixing 20 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 75 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until the mixture is uniform to obtain a mixture;

Example 5

Fully mixing 25 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 70 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until uniform to obtain a mixture;

adding the mixture into a double-screw mixing extruder, melting, mixing, extruding, cooling, granulating, and drying the granules in a vacuum oven at 50 ℃ for 8 hours to obtain dried polycaprolactone composite granules; wherein the twin-screw temperature is set as follows: the first zone is 60 ℃, the second zone is 65 ℃, the third zone is 71 ℃, the fourth zone is 68 ℃, the fifth zone is 65 ℃, the head zone is 63 ℃, the rotating speed of the twin-screw is 32 r/min, and the granulating speed is 12.4 r/min;

Example 6

Fully mixing 30 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 65 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until uniform to obtain a mixture;

Comparative example 1

Fully mixing 15 parts by weight of Australian tea tree powder microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 80 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until uniform to obtain a mixture;

Comparative example 2

Firstly, fully mixing 15 parts by weight of chitosan microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 80 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until uniform to obtain a mixture;

Comparative example 3

Firstly, fully mixing 15 parts by weight of hemp stalk powder, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 80 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until the mixture is uniform to obtain a mixture;

finally, adding the dried polycaprolactone composite granules into a single-screw extruder for heating, melting and extruding, drawing, cooling, air-drying, and collecting wires to obtain the polycaprolactone composite wires capable of being used for 3D printing; wherein the single screw temperature is set as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the single screw rotation speed is 25 r/min.

Comparative example 4

Firstly, fully mixing 15 parts by weight of Australian tea tree composite microspheres, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 80.5 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until the mixture is uniform to obtain a mixture;

finally, adding the dried polycaprolactone composite granules into a single-screw extruder for heating, melting and extruding, drawing, cooling, air-drying, and collecting wires to obtain the polycaprolactone composite wires capable of being used for 3D printing; wherein, single screw rod temperature sets up as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the rotating speed of the single screw is 25 r/min.

Comparative example 5

Firstly, fully mixing 15 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose, 2 parts by weight of diatomite powder and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 81.5 parts by weight of polycaprolactone into the mixed powder, and continuously mixing until the mixture is uniform to obtain a mixture;

Comparative example 6

Firstly, fully mixing 15 parts by weight of Australian tea tree composite microspheres, 0.5 part by weight of microcrystalline cellulose and 1 part by weight of calcium carbonate to obtain mixed powder for later use; adding 1.5 parts by weight of tributyl citrate into 82 parts by weight of polycaprolactone, uniformly mixing, adding the mixed powder, and continuously mixing until uniform to obtain a mixture;

finally, adding the dried polycaprolactone composite granules into a single-screw extruder for heating, melting and extruding, drawing, cooling, air-drying, and collecting wires to obtain the polycaprolactone composite wires capable of being used for 3D printing; wherein, single screw rod temperature sets up as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the single screw rotation speed is 25 r/min.

Comparative example 7

Adding pure polycaprolactone into a single-screw extruder, heating, melting, extruding, drawing, cooling, air-drying, and collecting a wire rod to obtain a polycaprolactone composite wire rod for 3D printing; wherein, single screw rod temperature sets up as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the rotating speed of the single screw is 25 r/min.

Comparative example 8

The existing polycaprolactone 3D printing wire in the market is grey white, is similar to the material prepared by the invention, has the wire diameter of 1.70-1.79mm, and has the production date similar to the experiment implementation date of the invention.

Performance evaluation:

the evaluation results of the 3D printing wires and the test samples obtained in examples 1 to 6 and comparative examples 1 to 8 are shown in table 1.

TABLE 1 test results of examples and comparative examples

And (3) testing results: according to the test results of the examples 1 to 6, the antibacterial rate of the Australia tea tree composite microsphere is increased along with the increase of the weight part, and the antibacterial rate is obviously increased compared with that of a blank comparative example (comparative example 7); according to the test results of the example 3 and the comparative examples 1 to 3, the composite microspheres prepared from the Australian tea tree powder and the chitosan oligosaccharide have better and more obvious antibacterial effects compared with the single Australian tea tree powder microspheres and chitosan oligosaccharide microspheres, and compared with the Hanma rod powder of the comparative example 3 which is the same type of plant powder with antibacterial property, the Australian tea tree composite microspheres prepared by the invention have more obvious antibacterial effects and higher antibacterial rate; according to the test results of the embodiment 3 and the comparative example 4, if no microcrystalline cellulose is added, the tensile strength, the elongation at break and the bending strength of the composite material are reduced to a certain extent, the average curing time is increased, the main factors are that more microcrystalline regions are formed in the process of re-cooling polycaprolactone due to the addition of microcrystalline cellulose particles, the cooling and curing of the material are accelerated, the mechanical strength is improved, and in the process of stretching under external force, the regular microcrystalline region polycaprolactone molecular chains are neatly folded, compared with the disordered polycaprolactone molecular chain arrangement with less microcrystalline regions when no microcrystalline cellulose is added, the polycaprolactone molecular chains folded and arranged in the same volume are more, and more longer straightening spaces are formed in the process of stretching under external force, so that the elongation at break of the test sample of the embodiment 3 after the microcrystalline cellulose is added is larger; according to the test results of the embodiment 3 and the comparative example 5, the melting temperature of the composite material is obviously improved by 1 ℃ without adding tributyl citrate, and the melting index of the composite material is also obviously reduced without adding tributyl citrate, so that the slow or unsmooth discharge of the prepared printing wire in the printing process is caused by combining the two factors; according to the test results of the example 3 and the comparative example 6, the diatomite powder is not added, so that the melting temperature is reduced, the melt index is improved, the cooling solidification time is greatly prolonged, and the tensile strength and the bending strength are obviously reduced; the CCK-8 experimental method is adopted to test that the materials of the examples 1-6 and the comparative examples 1-7 have no cytotoxicity, compared with the existing printing consumables in the market of the comparative example 8, the printing consumables have slight micro toxicity or low toxicity due to addition of various additives or modification, and the antibacterial effect is not obvious, which also shows that the composite material has good safety performance, does not generate adverse side effect after contact with children or users, and can be used safely; in addition, as is clear from the electron micrographs of fig. 2 and 3, pure australian tea tree powder (fig. 2) can be seen to be messy and in the form of short fibers in strips, and the modified australian tea tree powder and chitosan oligosaccharide and the like prepared into composite particles (fig. 3) is obviously more regular and in the form of spheroids or microspheres, which facilitates dispersion and uniform mixing in the composite material.

The above embodiments are part of the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and they are included in the scope of the present invention.

Claims

1. The preparation method of the Australia tea tree composite microspheres is characterized by comprising the following steps:

(1) Cutting the Australian tea tree trunks into particles or small segments, baking the particles or small segments until the particles or the small segments are dried, and then crushing and sieving the particles to obtain Australian tea tree trunks powder;

(2) Adding the obtained Australian tea tree powder into the modified solution for uniform dispersion, performing ultrasonic treatment, stirring at 50-70 ℃ for reaction for 3-8h, keeping stirring and cooling to room temperature, filtering, washing, drying, refining and sieving to obtain modified Australian tea tree powder;

(3) Preparing aqueous solution with the total concentration of polyvinyl alcohol and polyvinylpyrrolidone being 2.5-3.5 wt%; preparing a water solution with the concentration of chitosan oligosaccharide of 1-2 wt%; then mixing the two aqueous solutions uniformly to obtain a mixed solution; wherein the weight ratio of the polyvinyl alcohol and polyvinylpyrrolidone aqueous solution to the chitosan oligosaccharide aqueous solution is (1-5): (1-10);

(4) And adding the modified Australian tea tree powder into the mixed solution, uniformly dispersing, preparing powder particles by a spray drying process, drying, refining and sieving to obtain the Australian tea tree composite microspheres.

2. The method of claim 1, wherein: the production place of the branch of the Australian tea tree in the step (1) is the autonomous Yao county of milk Yao nationality in Shaoguan city or the Source Wenyuan county in Shaoguan city, and the branch of the Australian tea tree waste residue is extracted by essential oil or is not extracted by the essential oil.

3. The method of claim 1, wherein: the modifier solution in the step (2) is an ethanol solution with the modifier concentration of 3-8wt%, the pH value is adjusted to 8-9, the modifier is a composition of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, diethylenetriamine and ammonium dodecylbenzenesulfonate, and the mass ratio of the three is (2-10): (0.1-0.5): (1-3).

4. The method of claim 1, wherein: the weight ratio of the content of the modifier in the modifying solution in the step (2) to the Australia tea tree powder is 1: (1-10).

5. The method of claim 1, wherein: in the step (3), the weight ratio of the polyvinyl alcohol to the polyvinylpyrrolidone is (4-10): (1-5), the molecular weight of the chitosan oligosaccharide is 500-5000.

6. The method of claim 1, wherein: controlling the spray drying process in the step (4): the inlet temperature was 103 deg.C, the outlet temperature was 70 deg.C, and the frequency of the sparger was between 20 and 40 Hz.

7. The method of claim 1, wherein: the weight ratio of the modified Australia tea tree powder used in the step (4) to the mixed solution is 1: (10-100).

8. A preparation method of a Australia tea tree 3D printing composite material is characterized by comprising the following steps:

uniformly mixing 5-30 parts by weight of Australia tea tree composite microspheres obtained by the preparation method of any one of claims 1-7, 0.1-1 part by weight of microcrystalline cellulose, 0.2-2 parts by weight of diatomite powder and 0.1-2 parts by weight of calcium carbonate to obtain mixed powder A for later use; adding 0.5-2 parts by weight of tributyl citrate into 65-90 parts by weight of polycaprolactone, uniformly mixing, adding the obtained mixed powder A, and continuously mixing until the mixture is uniform to obtain a mixture B;

adding the mixture B into a double-screw extruder, melting, mixing, extruding, cooling, granulating and drying to obtain polycaprolactone composite granules;

and (III) adding the obtained polycaprolactone composite granules into a single-screw extruder for melt extrusion, drawing and drawing, cooling, air-drying, and collecting wires to obtain the Australia tea tree 3D printing composite material.

9. The method of claim 8, wherein: the temperature of the twin-screw extruder was set as follows: the first zone is 60 ℃, the second zone is 65 ℃, the third zone is 71 ℃, the fourth zone is 68 ℃, the fifth zone is 65 ℃, the head zone is 63 ℃, the double screw rotating speed is 32 r/min, and the grain cutting speed is 12.4 r/min.

10. The method of claim 8, wherein: the single screw temperature was set as: the first zone is 90 ℃, the second zone is 98 ℃, the third zone is 95 ℃, the head zone is 91 ℃, and the single screw rotation speed is 25 r/min.