CN112300384A

CN112300384A - Bio-based nylon, modified material thereof, preparation method and application of 3D printing

Info

Publication number: CN112300384A
Application number: CN202010984478.8A
Authority: CN
Inventors: 张维; 于天宇; 王妍
Original assignee: Beijing Lvcheng Biomaterial Technology Co ltd
Current assignee: Beijing Lvcheng Biomaterial Technology Co ltd
Priority date: 2020-09-18
Filing date: 2020-09-18
Publication date: 2021-02-02

Abstract

The invention discloses a bio-based nylon from a full bio-based source, a modified material and a preparation method thereof, and application of 3D printing, wherein furandicarboxylic acid and pentamethylenediamine which are prepared by taking biomass as raw materials are polymerized into biomass nylon under a high-temperature high-pressure catalytic system; adopting a modifier to perform reinforced modification on the synthesized bio-based nylon; and 3D printing is carried out after the modified bio-based nylon is made into wires. The furan ring structure is introduced into the molecular main chain of the bio-based nylon, so that the heat resistance and the mechanical property of the nylon are improved, and the water absorption of the nylon material is reduced; the modified bio-based nylon has high strength and good heat resistance, has performance superior to that of common nylon or nylon modified 3D printing wires, can be used in the aerospace field, and can be applied in the high-end equipment fields such as 3D printing and the like.

Description

Bio-based nylon, modified material thereof, preparation method and application of 3D printing

Technical Field

The invention relates to a preparation method of nylon, in particular to bio-based nylon, modified nylon and preparation methods and application thereof, belonging to the field of utilization of biological resources.

Background

Currently more than 99% of the world's nylon (PA) products are derived from petroleum, for example, the largest amount of PA66 monomer is produced from petroleum-based butadiene or acrylonitrile. With the increasing shortage of petroleum resources in the world, the search for alternatives to petroleum is urgent. The production of PA using renewable biomass materials as feedstock is an important direction to solve the petroleum problem.

At present, in order to improve the mechanical properties of PA, one of the methods is to introduce an aromatic ring partially into the molecular chain of aliphatic polyamide, which is usually prepared by homopolymerization, block copolymerization or random copolymerization of monomers such as aromatic dibasic acid and aliphatic diamine or aliphatic dibasic acid and aromatic diamine, and the main chain of the macromolecule contains a benzene ring and an amide group. The aromatic ring is partially introduced into a molecular chain, so that the aliphatic polyamide resin not only keeps the advantages of high crystallinity and good flexibility of the aliphatic polyamide, but also greatly improves the heat resistance and mechanical property of the polymer, simultaneously reduces the water absorption rate, has better cost performance, is a resin with high heat resistance between general engineering plastic nylon and high-temperature-resistant engineering plastic PEEK, is particularly suitable for producing some heat-resistant parts and thin-wall products, and has wide application in the fields of automobile engine peripheral parts, circuit board surface mounting technology, aerospace, mechanical bearing retainers, compressor valve plates and the like. With the rapid development of high and new technologies and the requirement of environmental protection, the market demand is on the rise, and scientific research and application development are both advanced.

However, the existing bio-based nylon is mainly synthesized by linear chain dibasic acid and 1, 5-pentanediamine, and has the defects of low strength and poor temperature resistance of the material; moreover, the aromatic ring for preparing the bio-based nylon at present is derived from fossil-based raw materials, and belongs to non-renewable resources.

Furan is the most similar bio-based aromatic ring rigid product with benzene ring, and is the only bio-based aromatic ring monomer with the potential to replace benzene ring at present. Therefore, the furan ring is introduced into the nylon to replace an aromatic ring to prepare the furan ring-containing all-bio-based nylon with excellent mechanical properties.

In order to further improve the performance of the all-bio-based nylon, the strength of the modified nylon is greatly enhanced through the modification of the carbon fiber and the glass fiber, and the all-bio-based nylon can be used in more severe fields such as aerospace, deep sea and the like. In addition, this patent makes the silk material of 3D printing with this reinforcing material for the additive manufacturing of non-metallic parts, confirms the printing forming parameter of this biobased nylon material simultaneously.

Disclosure of Invention

The invention aims to provide a bio-based nylon material, a preparation method and a modification method thereof and 3D printing of modified bio-based nylon, aiming at the technical problems in the existing bio-based nylon and the preparation method thereof. The invention develops a high-performance nylon material of a full-biological baseband furan ring, and a 3D printing wire rod with high strength and high temperature resistance is prepared by modifying glass fibers or carbon fibers, and then the material is subjected to printing research by an FDM process. The furan ring structure is introduced into the main molecular chain of the bio-based nylon material, so that the heat resistance and the mechanical property of a nylon product are improved, and the water absorption of the nylon material is reduced; the modified material is different from the common nylon material and can be used in the fields of high-end equipment such as aerospace and the like.

In order to achieve the object of the present invention, in one aspect, the present invention provides a method for preparing bio-based nylon, comprising

1) Under the protection of inert gas, adding 2, 5-furandicarboxylic acid, 1, 5-pentanediamine, a catalyst and water into a high-pressure reaction kettle, heating and pressurizing to perform prepolymerization reaction;

2) after the prepolymerization reaction is carried out for 2-5h, the temperature is continuously increased to 260 ℃ of 230-;

3) after the reinforced polycondensation reaction is carried out for 1-6h, the pressure in the reaction kettle is reduced to 1MPa under the condition that the temperature of the reaction system is 230-;

4) drying the prepolymer under reduced pressure, crushing to prepare prepolymer particles, heating and vacuumizing the prepolymer particles, and carrying out solid-phase polycondensation reaction at the temperature of 300-350 ℃ and under the vacuum condition of the relative pressure of 10-50KPa to obtain a white polyamide polymer, namely the bio-nylon bio-PA.

Wherein, the inert gas in the step 1) is nitrogen, helium or argon, preferably argon; the catalyst is a phosphorus-based compound.

In particular, the phosphorus-based compound is selected from PyBop (C)₁₈H₂₈F₆N₆OP₂) Sodium hypophosphite or sodium dihydrogen phosphate, preferably PyBop (C)₁₈H₂₈F₆N₆OP₂)。

Wherein the molar ratio of the 2, 5-furandicarboxylic acid to the 1, 5-pentanediamine is (1-2): 1, preferably 1: 1; the molar ratio of the catalyst to the 2, 5-furandicarboxylic acid is (0.005-0.5):1, preferably (0.005-0.2):1, more preferably 0.01: 1; the amount of water used is 4 to 12L of water per 1 mole of 2, 5-furandicarboxylic acid, preferably 5L of water per 1 mole of 2, 5-furandicarboxylic acid.

Wherein the reaction temperature of the prepolymerization reaction in the step 1) is 80-200 ℃, preferably 80-140 ℃, and more preferably 80 ℃; the pressure is 2 to 4MPa, preferably 2 to 3MPa, and more preferably 2 MPa.

Firstly, biomass is hydrolyzed to produce glucose, the glucose is respectively fermented and isomerized to produce lysine and 5-hydroxymethyl furfural, the lysine is decarboxylated to produce 1, 5-pentanediamine, and the 5-hydroxymethyl furfural is catalyzed and oxidized to produce 2, 5-furandicarboxylic acid. 2, 5-furandicarboxylic acid and 1, 5-pentanediamine are polymerized to produce bio-based nylon bio-PA. Biomass includes starch, sugars, ligno-cellulosic raw materials.

Wherein, the raw materials of 2, 5-furandicarboxylic acid and 1, 5-pentanediamine are glucose generated by hydrolyzing a biomass raw material, and the glucose is respectively subjected to a fermentation process and an isomerization dehydration process to produce lysine and fructose; lysine decarboxylase (EC.4.1.1.18) catalyzes the decarboxylation to produce 1, 5-pentanediamine; the fructose is dehydrated to generate 5-hydroxymethyl furfural, and then the 2, 5-furandicarboxylic acid is generated through catalytic oxidation reaction.

2, 5-Furanedicarboxylic acid is prepared according to methods known in the art for preparing 2, 5-furandicarboxylic acid from biomass feedstock.

Wherein the 2, 5-furandicarboxylic acid in the step 1) is prepared by the following method:

1A) hydrolyzing a biomass raw material to prepare glucose;

1B) mixing glucose, alkaline aqueous solution and D-xylose isomerase, heating, and carrying out isomerization reaction to obtain fructose;

1C) mixing fructose, a fructose dehydration catalyst and a high-boiling point solvent, heating, and carrying out fructose dehydration reaction to obtain 5-hydroxymethylfurfural (5-HMF);

1D) adding 5-HMF and catalyst into Na-filled solution₂CO₃Heating the aqueous solution in a reaction kettle, introducing oxygen into the reaction kettle, performing catalytic oxidation reaction, and separating to obtain the 2, 5-furandicarboxylic acid.

Wherein the pH of the mixed system of the glucose, the alkaline aqueous solution and the D-xylose isomerase in the step 1B) is 7-10, preferably 8.0.

In particular, the aqueous alkaline solution is selected from the salts or hydroxides of alkali metals, preferably K₂CO₃、Na₂CO₃Aqueous KOH or NaOH solution.

In particular, the molar ratio of glucose to alkali metal in the aqueous alkaline solution is 1: 2-6, preferably 1: 4; the molar ratio of the glucose to the D-xylose isomerase is 100: 0.5-2, preferably 100: 1.

in particular, the isomerization reaction temperature is 45-65 ℃, preferably 60 ℃; the isomerization reaction time is 0.2 to 1 hour, preferably 0.5 hour.

Wherein the fructose dehydration catalyst in the step 1C) is selected from Amberlyst-15 and SiO₂-Al₂O₃ZSM-5 or a heteropolyacid, preferably Amberlyst-15; the high boiling point solvent is dimethyl sulfoxide or DMF.

In particular, the molar ratio of the fructose to the catalyst Amberlyst-15 is 100: 1-5, preferably 100: 3; controlling the fructose dehydration reaction temperature to be 120-180 ℃, preferably 150 ℃; the reaction time is 15-30min, preferably 20 min.

Wherein the catalyst in the step 1D) is selected from Pd-Bi/Al₂O₃PK-216 ion resin or Amberlyst-15, preferably Pd-Bi/Al₂O₃(ii) a The Na is₂CO₃The pH of the aqueous solution is 8 to 10, preferably 9.0.

In particular, the pH during the catalytic oxidation reaction is between 8 and 10, preferably 9.0; the mass ratio of the catalyst to the 5-HMF is 0.2-1: 100, preferably 0.5: 100; the reaction temperature of the catalytic oxidation reaction is 40-60 ℃, and preferably 50 ℃; the pressure is 1.5-4MPa, preferably 2 MPa.

1, 5-Pentanediamine was prepared according to methods known in the art for the preparation of 1, 5-Pentanediamine from biomass feedstock.

The 1, 5-pentanediamine is prepared by the following method:

1a) hydrolyzing a biomass raw material to prepare glucose, and fermenting the glucose to prepare lysine salt;

1b) dissolving lysine salt in water to obtain lysine salt water solution with pH of 7.0;

1c) adding lysine decarboxylase (EC.4.1.1.18) into lysine salt aqueous solution, performing lysine decarboxylation enzymatic decarboxylation reaction at 35 deg.C to obtain 1, 5-pentanediamine salt solution, and adding acid solution during the reaction to maintain pH at 7.0;

1d) and (3) performing electrodialysis on the solution of the 1, 5-pentanediamine salt, and removing the salt to prepare the 1, 5-pentanediamine.

The 1, 5-pentanediamine can also be prepared by a chemical method or a biological method.

Wherein the prepolymerization time in the step 2) is preferably 2 h; the temperature of the enhanced polycondensation reaction is preferably 240 ℃ and 250 ℃, and more preferably 240 ℃; the pressure is preferably 2 to 3MPa, more preferably 2 MPa.

Particularly, the heating rate in the step 2) is 1-4 ℃/min, preferably 2.5 ℃/min.

Wherein, the time of the reinforced polycondensation reaction in the step 3) is preferably 2 to 4 hours, and is further preferably 2 hours; the pressure in the reaction kettle is reduced, and the pressure is preferably 1 MPa; the pressure reduction rate of the reaction kettle is 0.01-0.05MPa/min, preferably 0.017 MPa/min.

In particular, the prepolymer prepared by the intensive polycondensation in step 3) has a viscosity index of 115-125, preferably 120.

In particular, the viscosity index of the prepolymer in step 3) is determined using ASTM D1824-2016 Standard test method for apparent viscosity of plastisols and organosols at Low shear rates.

Wherein the particle size of the prepolymer particles in the step 4) is 20-50 μm.

In particular, the temperature of the solid phase polycondensation reaction is preferably 340 ℃; the pressure of the solid phase polycondensation reaction is preferably 30 KPa; the reaction time is 0.5 to 4 hours, preferably 0.5 to 2 hours, and more preferably 2 hours.

Wherein the relative pressure in the reduced-pressure drying process of the prepolymer is 10-50KPa, preferably 30 KPa; the temperature is 60-110 ℃, and the preferred temperature is 80 ℃; drying under reduced pressure until the water content of the prepolymer is less than 0.05%.

Wherein, the molecular formula of the bio-based nylon prepared in the step 4) is as follows:

wherein n is 85-110.

In another aspect, the invention provides a bio-based nylon prepared according to the above method.

The invention also provides a modification method of the bio-based nylon, which comprises the following steps: adding the bio-based nylon, the modifier and the modification auxiliary agent into a high-speed mixer, and uniformly mixing; then melting and blending the uniformly mixed materials through a double-screw extruder, and performing extrusion treatment; and cooling the extruded material to room temperature to obtain the modified bio-based nylon.

Wherein, the bio-based nylon: modifying agent: the weight portion ratio of the modified auxiliary agent is (40-80): (20-50): (5-10), preferably 60:30: 10.

Wherein, the modifier is selected from carbon fiber, glass fiber or aramid fiber.

In particular, the modifier is chopped carbon fibers or/and chopped glass fibers.

In particular, the chopped carbon fibers or chopped glass fibers have a length of 1-15 mm; the strength is 2-10 Gpa; modulus 100-; elongation of 1-10%.

Particularly, the chopped carbon fibers are selected from carbon fibers with the length of 1-10mm, preferably 2-4 mm; the chopped glass fiber is selected from glass fiber with the length of 0.5-6mm, preferably 1-2 mm.

Particularly, the chopped carbon fibers are T700,12K carbon fibers, and have the strength of 4.9Gpa, the modulus of 230Gpa, the elongation of 2.1 percent, the linear density of 800mg/m and the density of 1.80g/cm³。

Wherein the modification auxiliary agent comprises a compatilizer, an abrasion-resistant auxiliary agent and an antioxidant.

In particular, the compatilizer is selected from maleic anhydride grafted ethylene butyl acrylate, polyacrylate, oxazoline or maleic anhydride grafted fatty acid ester, preferably maleic anhydride grafted ethylene butyl acrylate; the wear-resistant auxiliary agent is Ethylene Bis Stearamide (EBS), glyceryl stearate, polydimethylsiloxane or oleamide, and is preferably EBS; the antioxidant is tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester (antioxidant 1010), 3, 5-di-tert-butyl-4-hydroxyphenylpropionyl-hexanediamine (antioxidant 1098), tris (2, 4-di-tert-butylphenol phosphite) (antioxidant 168) or potassium iodide, and is preferably tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester.

Particularly, the weight parts of the compatilizer, the wear-resistant additive and the antioxidant in the modified additive are (5-15): (0.1-0.5): (0.1-0.5), preferably 9.5:0.3: 0.2.

Particularly, the modification auxiliary agent also comprises a silane coupling agent and a nano silicon dioxide nucleating agent.

Particularly, the weight part ratio of the silane coupling agent is 0-2; the weight portion ratio of the nano silicon dioxide nucleating agent is 0-4.

And in the extrusion treatment process, the extrusion temperature is controlled to be matched with the melting temperature of the bio-based nylon.

In particular, the extrusion temperature during the extrusion treatment is 300-320 ℃.

In particular, the method comprises cooling the extruded material, drying the cooled extruded material, and then pelletizing the cooled extruded material.

In particular, the drying process before the pelletizing process resulted in the extrudate having a moisture content of less than 0.005%.

Particularly, the method also comprises the step of drying the cut materials at 80-100 ℃ for at least 3 h; drying until the water content of the granules is lower than 0.005%.

In another aspect, the invention provides a method for preparing a 3D printing wire, comprising: the method comprises the following steps: uniformly mixing the modified bio-based nylon and the pigment, and melting; and drawing and forming the molten liquid to prepare the 3D printing wire rod.

Wherein the weight ratio of the pigment to the modified bio-based nylon composite material is 0.5-4: 100, preferably 1: 100.

particularly, the mixture of the modified bio-based nylon and the pigment is extruded into a plastic melt in a single-screw extruder, and the obtained plastic melt is subjected to hot water treatment, cold water cooling and shaping and air drying to obtain the modified bio-based nylon wire.

In particular, the extrusion temperature of the extruder, i.e., the temperature at which the compound melts, is the melting temperature of the bio-based nylon.

In particular, the temperature of the mixture melting is 300-320 ℃.

Through the synergistic effect among the raw materials, the prepared printing wire is not easy to warp after being molded, and the quality of a molded product is greatly improved.

The purpose of modifying the bio-based nylon is to improve the strength of the bio-based nylon, reduce the warpage/shrinkage of materials, improve the tensile modulus, obviously improve the thermal property and resist higher temperature.

3D printing parameter control

The carbon fiber and glass fiber modified bio-based nylon wire belongs to an innovative product and is not researched by 3D printing. The material has higher melting point and use temperature, so the printing technology and parameters are different from other common nylon materials for 3D printing.

According to the research, the 3D printing wire of the reinforced bio-based nylon material is confirmed to have the nozzle temperature of 290-350 ℃, the constant temperature bin and the platform temperature of 120-150 ℃. Under this condition, stable material printing can be achieved.

The existing bio-based nylon materials are all polymers of fatty acid families and have the defects of low strength and poor temperature resistance.

Compared with the prior art, the invention has the following advantages:

1. the raw materials used for synthesizing the bio-based nylon prepared by the method are all derived from bio-based materials, and the bio-based nylon has rich and renewable raw materials.

2. The method obtains the monomer and the nylon product with high selectivity and high yield by optimizing the synthesis process of the monomer and the nylon.

3. The bio-based nylon is different from common linear bio-based nylon, such as PA56, PA510, PA518 and the like, and the bio-based nylon prepared by the method has a bio-based high molecular furan ring monomer with a 'rigid' planar structure, so that the heat resistance and the mechanical property are obviously improved.

4. According to the invention, the bio-based nylon with the 'rigid' structure is modified by carbon fiber or glass fiber for the first time to prepare the 3D printing wire, and the obtained modified bio-based nylon has high strength and good heat resistance, has better performance than that of common nylon or nylon modified 3D printing wire, and can be used in the field of aerospace.

5. According to the invention, the bio-based modified nylon containing furan rings is used in the field of 3D printing for the first time, and the printing parameters are obtained.

Drawings

FIG. 1 is a flow chart of the preparation of bio-based nylon.

Detailed Description

The invention will be further described with reference to specific embodiments, and the advantages and features of the invention will become apparent as the description proceeds. These examples are illustrative only and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and modifications may be made without departing from the spirit and scope of the invention.

The raw material glucose for preparing the bio-based nylon monomer is prepared by hydrolyzing a biomass raw material. The preparation of glucose from biomass feedstock is a conventional technique in the art. Other sources of glucose are also suitable for use as the feedstock in the present invention.

Example 1: preparation of bio-based nylon monomer

1. Preparation of lysine and 5-hydroxymethyl furfural by biomass hydrolysis

Biomass (corn, sugarcane, straw and the like) is hydrolyzed to produce glucose, and the glucose is respectively fermented and isomerized to produce lysine and 5-hydroxymethylfurfural. Lysine and 5-hydroxymethylfurfural are produced from biomass by methods known in the art.

2. Biological method for preparing 1, 5-pentanediamine

The decarboxylation of lysine catalyzed by decarboxylase (EC.4.1.1.18) produces 1, 5-pentanediamine.

As is known to those skilled in the art, the carboxyl groups at both ends of lysine are removed by lysine decarboxylase (EC4.1.1.18) to produce pentamethylene diamine.

For example, a specific biological method for preparing pentanediamine is disclosed in 'L-lysine decarboxylase property and application research' (Jiangli, Nanjing university, Master thesis, 2007).

For example, the specific biological method for the preparation of pentanediamine is disclosed in "research on the transformation of L-lysine into cadaverine by microorganisms" (ZhuJing, Tianjin science and technology university, Master's paper, 2009.3).

The preparation method comprises the following steps:

dissolving lysine salt (such as sodium lysine) in water to obtain lysine salt water solution with pH of 7.0;

adding lysine decarboxylase (EC.4.1.1.18) into lysine salt aqueous solution, performing lysine decarboxylation enzymatic decarboxylation reaction at 35 deg.C to obtain 1, 5-pentanediamine salt solution, and adding acid solution during the reaction to maintain pH at 7.0;

filtering the obtained 1, 5-pentanediamine salt solution by using an ultrafiltration membrane with the molecular weight cutoff of 3000-6000 to obtain 1, 5-pentanediamine salt ultrafiltrate and a lysine decarboxylase solution, and recycling the separated lysine decarboxylase solution after treatment;

feeding the obtained enzyme-removed 1, 5-pentanediamine salt ultrafiltrate into a two-chamber bipolar membrane electrodialysis device, desalting under the conditions of current density of 50mA/cm2, voltage of 20V and temperature of 25 ℃ to obtain a 1, 5-pentanediamine aqueous solution with mass concentration of 30% and a lysine solution with concentration of 25g/L, and recovering the lysine solution for adjusting the pH of enzymatic decarboxylation reaction and desorbing and reusing the macroporous adsorption resin;

concentrating and dehydrating the obtained 1, 5-pentamethylene diamine aqueous solution with the mass concentration of 30% under the conditions of normal pressure and 100 ℃, then carrying out reduced pressure distillation at the temperature of 120 ℃, and condensing the light phase to obtain the 1, 5-pentamethylene diamine product.

The pentanediamine can also be prepared by a chemical method or a biological method.

3. Biological method for preparing 2, 5-furandicarboxylic acid

Glucose adopts a biological enzyme method to isomerize and produce fructose, and the production condition is that K is used under the alkaline condition at 60 DEG C₂CO₃The pH is controlled to be 8, and the conversion rate of the reaction of catalyzing glucose to generate fructose by using D-xylose isomerase as a catalyst is 65%.

3-1) preparation of fructose

Adding glucose, alkaline aqueous solution and D-xylose isomerase into a reaction kettle, and uniformly mixing, wherein the pH value of a mixed system is 8.0 (usually 7-10); wherein the alkaline aqueous solution is selected from alkali metal salt or hydroxide (preferably K)₂CO₃、Na₂CO₃Aqueous KOH or NaOH); the molar ratio of glucose to alkali metal in the aqueous alkaline solution is 1:4 (usually 1: 2-6); the molar ratio of glucose to D-xylose isomerase was 100: 1 (typically 100: 0.5-2);

heating to raise the temperature of the mixed reaction system, and carrying out isomerization reaction under the condition of keeping the temperature at 60 ℃ (usually at 45-65 ℃) for 0.5h (usually 0.2-1h) to prepare fructose, wherein: after high-resolution liquid chromatography (HPLC), the yield is analyzed, and the conversion rate of the reaction for generating fructose by catalyzing glucose with D-xylose isomerase as a catalyst is 65%.

Performing separation and purification treatment on a system after isomerization reaction by using Ca ion exchange resin, and then performing crystallization treatment to obtain purified fructose for subsequent catalytic dehydration of fructose to prepare 5-hydroxymethylfurfural; or directly using pure fructose purchased for catalytic dehydration reaction.

3-2) preparation of 5-hydroxymethylfurfural

Putting fructose, a fructose dehydration catalyst and a high-boiling point solvent dimethyl sulfoxide (DMSO) into a reaction kettle to perform fructose dehydration reaction, wherein: selecting Amberlyst-15 as fructose dehydration catalyst; the molar ratio of the fructose to the catalyst Amberlyst-15 is 100: 3 (typically 100: 1-5); the reaction temperature for fructose dehydration is 150 ℃ (usually 120 ℃ - & 180 ℃); performing dehydration reaction for 20min (usually 15-30min), and separating and purifying to obtain 5-hydroxymethylfurfural (5-HMF).

Conversion and yield were calculated by liquid chromatography analysis, with 100% fructose conversion and 98% yield of 5-hydroxymethylfurfural (5-HMF).

In a particular embodiment of the invention, the fructose dehydration catalyst is illustrated by Amberlyst-15, and other catalysts such as SiO₂-Al₂O₃、ZSM-5Or heteropolyacids are also suitable for use in the present invention; the solvent is exemplified by the high boiling point solvent dimethyl sulfoxide (DMSO), and other solvents such as DMF are also suitable for use in the present invention.

3-3) preparation of 2, 5-Furanedicarboxylic acid

5-HMF and a catalyst Pd-Bi/Al₂O₃Adding into a container containing Na₂CO₃Heating the aqueous solution in a reaction kettle, and introducing oxygen into the reaction kettle to perform catalytic oxidation reaction, wherein: na (Na)₂CO₃The pH of the aqueous solution is 9.0 (typically 8-10); i.e. controlling the pH during catalytic oxidation to 9.0 (typically 8-10); the mass ratio of catalyst to 5-HMF is 0.5:100 (typically 0.2 to 1: 100); the reaction temperature of the catalytic oxidation reaction is usually 40 to 60 ℃ at 50 ℃); a pressure of 2MPa (usually 1.5-4 MPa);

the catalyst is an oxidation catalyst except Pd-Bi/Al₂O₃In addition, other catalysts such as PK-216 ion resin, Amberlyst-15 are also suitable.

Performing catalytic oxidation reaction for 1h (usually 0.5-2h), and performing column separation to obtain 2, 5-furandicarboxylic acid (FDCA); the 5-HMF conversion was 100% and the 2, 5-furandicarboxylic acid (FDCA) yield was 99%.

Example 2: synthesis of bio-based nylon

1) In N₂2, 5-Furan dicarboxylic acid (156g, 1 mole), 1, 5-pentanediamine (102g, 1 mole), catalyst PyBop (5.2g, 0.01 mole), and 5L of water were charged to a 20L autoclave with the following protection, in which: the molar ratio of 2, 5-furandicarboxylic acid to 1, 5-pentanediamine is 1: 1; the molar ratio of 2, 5-furandicarboxylic acid to catalyst was 1: 0.01 (typically 1: 0.005-0.5); the amount of water added is 4-12L per 1 mole of 2, 5-furandicarboxylic acid.

2) Heating, pressurizing, stirring at 80 deg.C (usually 80-200 deg.C) and 2MPa (usually 2-4MPa), and performing prepolymerization under stirring;

during the prepolymerization, except for using N₂Besides protection, other inert gases such as argon, helium and the like are suitable for the invention; the molar ratio of 2, 5-furandicarboxylic acid to 1, 5-pentanediamine may also be 1-2: 1; 2, 5-furansThe molar ratio of the dicarboxylic acid to the catalyst was 1: 0.005-0:5 are suitable for use in the present invention. During the prepolymerization, the reaction system starts to polymerize to form nylon salt.

3) After the prepolymerization reaction is carried out for 2h (usually 2-5h), the temperature of the reaction system is slowly increased at the temperature rising speed of 2.5 ℃/min (usually 1-4 ℃/min), the reinforced polycondensation reaction is carried out under the conditions that the temperature is kept to be 240 ℃ (usually 230-;

4) after the polycondensation reaction is intensified for 2h (usually 1-6h), the pressure is gradually reduced to 1MPa within 1-1.5h under the condition of keeping the temperature at 240 ℃ (usually 230-.

The viscosity index of the prepolymer is determined using ASTM D1824-2016 Standard test method for apparent viscosity of plastisols and organosols at Low shear rates, the viscosity index of the prepolymer being 120 (typically 115- & 125);

5) drying the prepolymer under reduced pressure, wherein the relative pressure of the reduced pressure drying is 30KPa (usually 10-50 KPa); the temperature for drying under reduced pressure is 80 deg.C (usually 60-110 deg.C); drying until the water content is not more than 0.05%, and then crushing to obtain prepolymer particles with the particle size of 20-50 mu m; then vacuumizing and heating, and carrying out solid phase polycondensation reaction under the vacuum conditions of 340 ℃ (usually 300-.

The reduced pressure drying is to remove water at a relatively low temperature, and the water content is not more than 0.05%. The crushed particles are finally melted, and the particles are small and can be quickly melted.

The molecular formula of the prepared bio-based nylon bio-PA is as follows:

wherein n is 85-110.

According to Differential Scanning Calorimetry (DSC) part 2 of the national Standard method GB-T19466-1-2004 plastics: measuring the glass transition temperature of the prepared bio-based nylon bio-PA, wherein the measurement result is 135-150 ℃; differential Scanning Calorimetry (DSC) part 3: the melting and crystallization temperatures and the enthalpy of the prepared bio-based nylon bio-PA are measured, and the measurement result is that the melting temperature is 300-320 ℃.

Example 3 preparation of modified Bio-based Nylon

1. The raw materials were prepared in the following weight ratios (× 10g)

Bio-based nylon bio-PA 60

Modifier 30

Modification auxiliary 10

Wherein: the bio-based nylon bio-PA is prepared according to the method of example 1; the modifier is chopped carbon fibers, and the length of the chopped carbon fibers is 2 mm; the modifying auxiliary agent comprises a compatilizer, an anti-wear agent and an antioxidant; the compatilizer is maleic acid grafted ethylene butyl acrylate; the wear-resisting agent is Ethylene Bis Stearamide (EBS); the antioxidant is tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester; wherein the weight ratio of the compatilizer to the wear-resistant agent to the antioxidant in the modification auxiliary agent is 9.5:0.3: 0.2;

besides the chopped carbon fibers, the modifier can also be chopped glass fibers or aramid fibers; in the embodiment of the invention, the chopped carbon fibers adopt T700,12K carbon fibers, the strength is 4.9Gpa, the modulus is 230Gpa, the elongation is 2.1%, the linear density is 800mg/m, and the density is 1.80g/cm³；

The length of the chopped carbon fiber or glass fiber is generally 1-15mm, the strength is 2-10GPa, the modulus is 100-300GPa, and the elongation is 1-10%.

Compatibilizers besides maleic anhydride grafted ethylene butyl acrylate, also polyacrylates, oxazolines or maleic anhydride grafted fatty acid esters are suitable for use in the present invention;

in addition to EBS, an abrasion resistance aid, also glyceryl stearate, polydimethylsiloxane, or oleamide are suitable for use in the present invention;

antioxidants in addition to tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (antioxidant 1010), 3, 5-di-tert-butyl-4-hydroxyphenylpropionyl-hexamethylenediamine (antioxidant 1098), tris (2, 4-di-tert-butylphenol phosphite) (antioxidant 168) or potassium iodide are also suitable for use in the present invention.

2. Adding all the raw materials into a high-speed mixer, mixing at room temperature (15-30 deg.C), stirring, and stirring for 5min (usually 5-10min) to obtain modified material.

3. And melting and blending the uniformly mixed modified material through a double-screw extruder, and extruding, wherein the uniformly mixed modified material is added from a main feed inlet of the double-screw extruder, and the double-screw extruder extrudes and granulates to obtain modified particles, namely modified bio-based nylon granules (modified bio-based nylon composite material) are obtained, wherein in the extruding process of the extruder, the temperature of the extruder is controlled to be 300-: 300 ℃ in the first area, 305 ℃ in the second area, 314 ℃ in the third area, 315 ℃ in the fourth area, 314 ℃ in the fifth area, 310 ℃ in the sixth area, 310 ℃ in the seventh area, 310 ℃ in the eighth area, 308 ℃ in the ninth area, 308 ℃ in the tenth area, 308 ℃ in the eleventh area, 310 ℃ in the head, 450r/min of the main machine rotation speed and 10r/min of the feeding frequency.

In the extrusion granulation process of the extruder, after water cooling treatment is carried out on an extruded material, drying and granulating are carried out in sequence to prepare the modified BIO-based granules (modified BIO-based nylon composite material (GX/BIO-PA)), wherein the drying treatment temperature is 80-100 ℃; the drying treatment time is 3h (usually 2-4h), wherein the water content of the modified granules is less than 0.05%. The purpose of the drying is to remove residual water from the pellets.

Example 3A preparation of Bio-based Nylon wire

The bio-based nylon of example 2 is pelletized and dried at 100 ℃ (usually 80-100 ℃) for at least 3 hours until the water content is lower than 0.05%, and then the dried pellets and the pigment are mixed in proportion and added into a single screw extruder, wherein the weight ratio of the pigment to the bio-based nylon is 1: 100 (typically 0.5-4: 100);

extruding a plastic melt from the mixture of the granules and the pigment in a single-screw extruder, and carrying out hot water treatment, cold water cooling and shaping and air drying on the obtained plastic melt to obtain the bio-based nylon wire, wherein: the temperature of each heating interval of the single-screw extruder is set as follows: the first zone is 280-305 ℃, the second zone is 305-315 ℃, the third zone is 305-315 ℃, the fourth zone is 305-315 ℃, the fifth zone is 300-315 ℃, the sixth zone is 305-315 ℃, the hot water temperature is 55-65 ℃, and the cold water temperature is 30-40 ℃.

Example 3B preparation of modified Bio-based Nylon wire

Drying the modified particles prepared in example 3 at 100 ℃ (usually 80-100 ℃) for at least 3h, drying until the water content is lower than 0.05%, mixing the dried particles and a pigment according to a proportion, and adding the mixture into a single-screw extruder, wherein the weight ratio of the pigment to the modified bio-based nylon composite material is 1: 100 (typically 0.5-4: 100);

extruding a plastic melt from the mixture of the modified granular materials and the pigment in a single-screw extruder, and carrying out hot water treatment, cold water cooling and shaping and air drying on the obtained plastic melt to obtain the modified bio-based nylon wire, wherein: the temperature of each heating interval of the single-screw extruder is set as follows: the first zone is 280-305 ℃, the second zone is 305-315 ℃, the third zone is 305-315 ℃, the fourth zone is 305-315 ℃, the fifth zone is 300-315 ℃, the sixth zone is 305-315 ℃, the hot water temperature is 55-65 ℃, and the cold water temperature is 30-40 ℃.

The bio-based nylon and the carbon fiber modified bio-based nylon wire material developed by the invention belong to innovative products and are not researched by 3D printing.

Example 43D printing

1. Preparing a bio-based nylon wire prepared in example 3A into a 1A type test sample meeting the test requirement by adopting 3D printing equipment (Finland Minifictification ultra) according to ISO 527-2 plastic tensile property test method, wherein the temperature of a spray head is set to be 340 ℃, and the temperature of a constant temperature bin and the temperature of a platform are set to be 140 ℃; under the set conditions, stable material printing can be realized.

The prepared type 1A test sample is subjected to a tensile strength test according to ISO 527-2 plastic tensile property test method, and the test results are shown in Table 1.

2. Preparing a bio-based nylon wire prepared in example 3A into a test sample meeting the test requirement by adopting 3D printing equipment (Finland Minifictification ultra) according to ISO 178-2 plastic tensile property test method, wherein the temperature of a spray head is set to be 340 ℃, and the temperature of a constant temperature bin and a platform is set to be 140 ℃; the sample size is 80mm multiplied by 10mm multiplied by 4 mm; under the set conditions, stable material printing can be realized.

The bending strength of the prepared test specimens was measured in accordance with ISO 178-2 test method for tensile Properties of plastics, and the test results are shown in Table 1.

3. The bio-based nylon wire prepared in example 3A was subjected to 3D printing according to ISO75 determination of plastic deformation temperature under load, to prepare a test sample meeting the test requirements, wherein the sample size is 80mm × 10mm × 4 mm; under the set conditions, stable material printing can be realized.

The prepared test specimens were subjected to the heat distortion temperature test according to method A (bending stress of 1.80 MPa) of ISO75 determination of plastic load distortion temperature, and the test results are shown in Table 1.

Example 4A 3D printing

The same as example 4 except that the modified bio-based nylon wire prepared in example 3B was used for 3D printing.

The results of measurement of tensile strength, flexural strength and heat distortion temperature are shown in Table 1.

Comparative example 13D printing

Carbon fiber reinforced nylon 12 wire manufactured by norsbury corporation was used as comparative example 1, 3D printing was performed according to the method of example 4, and tensile strength, flexural strength, and heat distortion temperature of the test sample were measured, and the test results are shown in table 1.

TABLE 13D printed Material Performance test results

The above-described embodiments of the present invention are merely exemplary and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

1. The preparation method of the bio-based nylon is characterized by comprising the following steps:

4) drying the prepolymer under reduced pressure, crushing to prepare prepolymer particles, heating and vacuumizing the prepolymer particles, and carrying out solid-phase polycondensation reaction under the vacuum conditions of the temperature of 300-350 ℃ and the relative pressure of 10-50KPa to obtain a white polyamide polymer, namely the bio-nylon bio-PA.

2. The method according to claim 1, wherein the reaction temperature of the prepolymerization in step 1) is 80 to 200 ℃; the pressure is 2-4 MPa.

3. The process according to claim 1 or 2, wherein the molar ratio of 2, 5-furandicarboxylic acid to 1, 5-pentanediamine in step 1) is (1-2): 1; the molar ratio of the catalyst to the 2, 5-furandicarboxylic acid is (0.005-0.5): 1.

4. The method as set forth in claim 1 or 2, wherein the heating temperature-increasing rate in the step 2) is 1 to 4 ℃/min.

5. A biobased nylon prepared by the method of any one of claims 1 to 4.

6. A preparation method of modified bio-based nylon is characterized by comprising the following steps: firstly: adding the bio-based nylon prepared by the method of any one of claims 1 to 5, a modifier and a modification auxiliary agent into a high-speed mixer, and uniformly mixing; then: melting and blending the uniformly mixed materials through a double-screw extruder, and performing extrusion treatment; then: and cooling the extruded material to room temperature to obtain the modified bio-based nylon.

7. The method as claimed in claim 6, wherein the weight parts of the bio-based nylon, the modifier and the modification auxiliary agent are (40-80): (20-50): (5-10).

8. The method of claim 6 or 7, wherein the modifier is selected from carbon fiber, glass fiber or aramid fiber.

9. The method of claim 6 or 7, wherein the modifying aids comprise compatibilizers, abrasion resistance aids, antioxidants.

10. The method as claimed in claim 9, wherein the compatilizer, the wear-resistant assistant and the antioxidant are mixed in the following weight ratio (5-15): (0.1-0.5): (0.1-0.5).