CN105801819B - A kind of copolyesters for being adapted as 3D printing material and preparation method thereof - Google Patents

Abstract

The present invention discloses a kind of copolyesters for being adapted as 3D printing material and preparation method thereof, by reasonably selecting raw material composition and proportion design, and using the method for fat polymerization, obtain that heat endurance is good, the copolyesters for being adapted as 3D printing material of excellent in mechanical performance.By copolyester material produced by the present invention, its tensile strength is more than 45MPa, and notch impact strength is more than 5.0KJ/m², elasticity modulus is more than 700MPa, effectively meets performance requirement of the 3D printing technique to raw material, available for the 3D making of functional mechanical part, and meets environmentally protective performance requirement of the 3D printing technique to raw material without gas release in print procedure；Meanwhile the present invention is to prepare copolyester material by the method for direct copolyreaction, preparation process is simple, reduces cost, and can effectively avoid the consistency problem brought by blending.

Description

A kind of copolyester suitable as 3D printing material and preparation method thereof

technical field

The invention relates to a copolyester and a preparation method thereof, in particular to a copolyester suitable as a 3D printing material and a preparation method thereof.

Background technique

3D printing technology is an emerging manufacturing technology using additive manufacturing. Its appearance has subverted the long-standing model of subtractive manufacturing technology used in traditional manufacturing. Because it can directly print parts of any complex shape through computer graphics data, it can effectively simplify the product manufacturing process, shorten the product development cycle, improve efficiency and reduce costs, and can be used to verify product appearance, part assembly relationship and functional testing , is receiving more and more attention.

Fusion extrusion deposition molding (FDM) is a commonly used technology in 3D printing technology. At present, 95% of the polymer materials commonly used in fusion extrusion deposition molding technology in the market are acrylic-butadiene-styrene ternary copolymers. material (ABS) and polylactic acid (PLA) as the matrix. The latest research from the Illinois Institute of Technology in the United States found that printers using ABS and PLA polymers as plastic raw materials have higher emissions of ultrafine particles, and ABS is toxic, has a heavy processing odor, and is easily deformed during extrusion processing; PLA has poor thermal stability and crystallization. Slow speed, poor toughness, and PLA is a biocompatible polymer widely used in the manufacture of drug capsules, so the development of new functional polymer materials for 3D printing is of great significance to the rapid development of the 3D printing field.

Copolyester materials have high strength, good thermal stability, excellent molding processability, and good stain resistance and wear resistance. They are widely used in fiber, clothing, packaging, binding, shoemaking, Building materials, automobile and other industries. However, some defects of copolyester limit its application in the field of 3D printing.

Although the patent CN103980674A provides a method for controlling the polyester oligomer melt and the flow rate of inorganic substances in the jet mixing process to prepare inorganic/polyester composite materials with high inorganic content, the compatibility between the two is not good. Well, the inorganics are not evenly dispersed. Patent CN103980672A discloses a method of using aromatic polycarbonate and aromatic polyester to carry out blending modification to improve its impact resistance, and then irradiating with electron beams to make it cross-linked to a certain extent, but the method is complicated and costly. higher. Patent CN103980674A discloses a polyester composite material containing inorganic substances, but the compatibility between the two is not good, and the polymer melt viscosity is high. Patent CN1170418A discloses a biodegradable copolyester, which is esterified and prepolymerized with aliphatic dibasic acid and aliphatic dibasic alcohol, and then mixed with ester derivatives of aromatic dibasic acid, fatty Family diols are mixed for transesterification, and polycondensation is completed to obtain copolyester, but the tensile strength of the obtained polyester is relatively low at about 27MPa, and the heat resistance is poor, and the heat distortion temperature is about 70°C, which is also relatively low.

Contents of the invention

The purpose of the present invention is to solve the above technical problems, and propose a copolyester suitable for 3D printing materials and its preparation method. The copolyester prepared by the present invention can effectively meet the performance requirements of 3D printing materials.

The technical solution adopted in the present invention is: a copolyester suitable as a 3D printing material, and its raw materials are composed of dibasic acid composed of terephthalic acid, isophthalic acid and sebacic acid, 1,3 - propylene glycol, catalysts, antioxidants, additives and auxiliaries;

Wherein, the mol ratio between each raw material is respectively:

Dibasic acid: propylene glycol=1:1.50～1.80;

Terephthalic acid: isophthalic acid: sebacic acid=3:7:0.1～0.4;

The catalyst is tetrabutyl titanate, the mass of which is 0.04-0.06% of the total mass of the dibasic acid;

The antioxidant is tris(2,4-di-tert-butylphenyl) phosphite, the mass of which is 0.1-0.5% of the total mass of the dibasic acid;

The additive is selected from one of powdered glass fiber, nano-silica, and nano-calcium carbonate, and its mass is 10-20% of the total mass of the dibasic acid;

The additive is selected from one of oleic acid, polyethylene wax or sodium polyamide, and its mass is 0.5-1% of the total mass of the dibasic acid.

The above-mentioned preparation method suitable for copolyester as 3D printing material comprises the following steps:

(1) Put the dibasic acid composed of terephthalic acid, isophthalic acid and sebacic acid together with 1,3-propanediol and catalyst into the esterification kettle in proportion to carry out esterification reaction, the reaction temperature is 170℃～ 215°C, when the amount of distilled water is more than 95% of the theoretical water output, the esterification reaction ends;

(2) Add antioxidants, additives, and auxiliary agents to the product obtained in step (1) in proportion, and carry out reduced-pressure compression polymerization under the conditions of 235-260°C and 40-80Pa for 2.5h-3h, and the polymerization stage is completed;

(3) Nitrogen gas is passed, the vacuum is released, and the material is discharged into cold water while it is hot, so as to obtain a copolyester suitable for 3D printing materials.

The beneficial effect of the present invention is to obtain a copolyester suitable for 3D printing materials with good thermal stability and excellent mechanical properties by rationally selecting the composition of raw materials and proportioning design, and adopting the method of esterification polymerization. The copolyester material prepared by the present invention has a tensile strength greater than 45MPa, a notched impact strength greater than 5.0KJ/m ² , and an elastic modulus greater than 700MPa, effectively meeting the requirements of 3D printing technology on the mechanical properties and deformation resistance of raw materials , can be used for 3D production of functional mechanical parts, and there is no gas release during the printing process, which meets the environmental protection performance requirements of 3D printing technology for raw materials; at the same time, the present invention prepares copolyester materials through direct copolymerization. The preparation process is simple, the cost is reduced, and the compatibility problem caused by blending can be effectively avoided.

Detailed ways

The present invention is further illustrated below by examples, but the present invention is not limited to these examples.

Example 1

232g (1.4mol) of terephthalic acid, 99.6g (0.6mol) of isophthalic acid, 4.04g (0.02mol) of sebacic acid, 230.28g (3.03mol) of 1,3-propanediol, and 0.166g of tetrabutyl titanate g, into the 1L reactor. The reaction kettle is equipped with stirring, temperature measuring system, rectification column and reflux condenser. After gradually raising the temperature to 100°C, the stirring is started. When the temperature is close to 170°C, water begins to distill out, and the distillation temperature is 98-100°C. Raise the temperature to about 215°C, and the esterification reaction ends when the water output reaches more than 95% of the theoretical value. Add 0.332g antioxidant, 33.2g additive (nano-calcium carbonate) and 1.1869g auxiliary agent (oleic acid) again, carry out decompression compression polymerization reaction, raise temperature gradually to 260 ℃, keep warm; The pressure in the reactor gradually reduces to 50Pa, and maintained for 3 hours, the polycondensation reaction can be completed. Nitrogen gas is passed, the vacuum is released, and the material is discharged into cold water while it is hot, and the product obtained is designated as A1.

Example 2

232g (1.4mol) of terephthalic acid, 99.6g (0.6mol) of isophthalic acid, 10.1g (0.05mol) of sebacic acid, 233.7g (3.075mol) of 1,3-propanediol, and 0.1711 g, into the 1L reactor. The reaction kettle is equipped with stirring, temperature measuring system, rectification column and reflux condenser. After gradually raising the temperature to 100°C, the stirring is started. When the temperature is close to 170°C, water begins to distill out, and the distillation temperature is 98-100°C. Raise the temperature to about 215°C, and the esterification reaction ends when the water output reaches more than 95% of the theoretical value. Add 0.3421g antioxidant, 51.315g additive (nano silicon dioxide) and 2.0410g auxiliary agent (polyethylene wax) again, carry out decompression compression polymerization reaction, raise temperature gradually to 255 ℃, keep warm; As small as 50Pa and maintained for 3 hours, the polycondensation reaction can be completed. Nitrogen is passed, the vacuum is released, and the material is discharged into cold water while it is hot, and the product obtained is designated as A2.

Example 3

232g (1mol) of terephthalic acid, 99.6g (0.6mol) of isophthalic acid, 16.16g (0.08mol) of sebacic acid, 252.93g (3.328mol) of 1,3-propanediol, and 0.1741g of tetrabutyl titanate , into the 1L reactor. The reaction kettle is equipped with stirring, temperature measuring system, rectification column and reflux condenser. After gradually raising the temperature to 100°C, the stirring is started. When the temperature is close to 175°C, water begins to distill out, and the distillation temperature is 98-100°C. Raise the temperature to about 215°C, and the esterification reaction ends when the water output reaches more than 95% of the theoretical value. Then add 0..3482g antioxidant, 34.816g additive (powdered glass fiber) and 1.1062g auxiliary agent (sodium polyamide), carry out decompression compression polymerization reaction, gradually increase the temperature to 255 ° C, keep warm; the pressure in the reactor Gradually reduce to 50Pa, and maintain for 3 hours, the polycondensation reaction can be completed. Nitrogen is passed, the vacuum is released, and the material is discharged into cold water while it is hot, and the product obtained is designated as A3.

Example 4

232g (1mol) of terephthalic acid, 99.6g (0.6mol) of isophthalic acid, 10.1g (0.05mol) of sebacic acid, 280.44g (3.69mol) of 1,3-propanediol, and 0.1711g of tetrabutyl titanate , into the 1L reactor. The reaction kettle is equipped with stirring, temperature measuring system, rectification column and reflux condenser. After gradually raising the temperature to 100°C, the stirring is started. When the temperature is close to 175°C, water begins to distill out, and the distillation temperature is 98-100°C. Raise the temperature to about 215°C, and the esterification reaction ends when the water output reaches more than 95% of the theoretical value. Then add 0.3421g antioxidant, 68.42g additive (powdered glass fiber) and 1.1062g auxiliary agent (sodium polyamide), carry out decompression compression polymerization, gradually increase the temperature to 255 ° C, keep warm; the pressure in the reactor gradually decreases As small as 50Pa and maintained for 3 hours, the polycondensation reaction can be completed. Nitrogen is passed, the vacuum is released, and the material is discharged into cold water while it is hot, and the product obtained is designated as A4.

Performance Testing

The tensile strength and elongation at break of the obtained product refer to the standard GB/T 1701-2001; the melting point of the obtained product refers to the national standard GB/T3682-2000, and the notched impact strength refers to the national standard GB/T1043-2008.

The test results of the product are shown in Table 1 below:

Table 1: Product test results of each embodiment.

It can be clearly seen from the test results in the above table 1 that the copolyester material prepared by the present invention has a tensile strength greater than 45MPa and a notched impact strength greater than 5.3KJ/m ² , effectively meeting the mechanical properties of materials for 3D printing Requirement; Simultaneously, by the copolyester material prepared by the present invention, its elongation at break is lower (8.19%～12.53%), modulus of elasticity is higher (784MPa～950MPa), and its anti-deformation property is good, can be used for The 3D printing of functional mechanical parts with high material reliability requirements, and no gas release during the printing process, meets the environmental protection performance requirements of 3D printing technology for raw materials; moreover, the copolyester material prepared by the present invention , its melting point is relatively high (178.6 ° C ~ 183.9 ° C), and its thermal stability is good; in addition, the present invention prepares copolyester materials through the method of direct copolymerization reaction, the preparation process is simple, the cost is reduced, and it can effectively avoid the Compatibility issues brought about by blending.

Claims (1)

1. a kind of preparation method for the copolyesters for being adapted as 3D printing material, it is characterised in that include the following steps：

(1) by the binary acid being made of terephthalic acid (TPA), M-phthalic acid and decanedioic acid and 1,3- propane diols and catalyst one Rise, be proportionally added into esterifying kettle and carry out esterification, 170 DEG C~215 DEG C of reaction temperature, when the amount for distillating water goes out for theory Water more than 95% when, esterification terminates；

(2) antioxidant, additive, auxiliary agent are proportionally added into step (1) products therefrom, 235~260 DEG C, 40~ Depressurization condensation reaction 2.5h~3h is carried out under conditions of 80Pa, polymerization stage is completed；

(3) lead to nitrogen, release vacuum, discharge while hot into cold water, be adapted as the copolyesters of 3D printing material to obtain the final product；

Wherein, the molar ratio between each raw material is respectively：

The binary acid:1,3- propane diols=1:1.50~1.80；

The terephthalic acid (TPA):The M-phthalic acid:Decanedioic acid=1:0.43~0.6:0.014~0.08；

The one kind of the additive in pulverized glass fibres, nano silicon dioxide, nano-calcium carbonate, its quality are described two The 10~20% of first acid gross mass；

The one kind of the auxiliary agent in oleic acid, Tissuemat E or polyamide sodium, its quality for binary acid gross mass 0.5~ 1%；

The catalyst is butyl titanate, its quality is the 0.04~0.06% of binary acid gross mass；The antioxidant is Asia Tricresyl phosphate (2,4- di-tert-butyl-phenyl) ester, its quality are the 0.1~0.5% of binary acid gross mass.