CN104961881B - For 3D printing, the polyurethane material of the keys of Alder containing Diels and its production and use - Google Patents

Abstract

The invention discloses for 3D printing, the polyurethane material of the keys of Alder containing Diels and its production and use, it is characterized in 100 parts of diisocyanate by molfraction, 50~75 parts of PEPA or PPG, 50~125 parts of the glycol chain extender of the keys of Alder containing Diels, 0~50 part of diisocyanate trimer crosslinking agent.The polyurethane material of the keys of Alder containing Diels is during 3D printing, when temperature rises to critical-temperature, and Diels Alder keys fracture solution crosslinking, system viscosity is reduced rapidly, is conducive to 3D printing process；When the temperature decreases, Diels Alder keys restructuring crosslinking, enhances the mechanical property of 3D printing product, and assign the function of its selfreparing and autoadhesion.

Description

For 3D printing, polyurethane material containing Diels-Alder bond and its preparation method and use

technical field

The invention relates to a polyurethane material used for 3D printing and containing Diels-Alder bonds, a preparation method and application thereof, and belongs to the field of polymer materials.

Background technique

In the past 20 years, 3D printing technology, as an emerging rapid prototyping technology, has developed very rapidly and is currently used in aerospace, national defense, biomedicine and other fields. 3D printing technology is based on digital models, using metal, ceramic and polymer materials, etc., to construct objects by layer-by-layer printing. Its types include fused deposition technology, selective laser sintering technology, stereolithography technology and layered solid manufacturing technology.

Selective laser sintering is the most widely used 3D printing technology. C.R.Dechard first proposed the idea of selective laser sintering in the patent US4863538 and successfully developed the laser sintering process in 1989. To put it simply, the laser beam is selectively sintered according to the layered section information under the control of the computer. After one layer is completed, the next layer is sintered. After all the sintering is completed, the excess powder is removed, and the sintered parts can be obtained. Among the materials that can be used in laser sintering, polymer materials have attracted much attention because of their excellent properties, but the polymers that can be used in the selective laser sintering process are very limited. Heinz Scholten et al proposed to use nylon-12 in the laser sintering process in the patent US6245281B1. At present, nylon-12 accounts for more than 95% of laser sintering polymer materials, and many polymer materials with excellent properties cannot be used in the laser sintering process, which greatly limits its application range.

The medical field is one of the most widely used fields of 3D printing. Polyurethane has excellent mechanical properties, excellent water resistance, good biocompatibility, anticoagulation, no toxic side effects, and is easy to process. The degree of freedom in molecular design is particularly extensive in the medical field. The use of polyurethane in 3D printing has been rarely reported. Lanbijian disclosed a polyurethane material that can be used for 3D printing in the patent CN104177815. In this method, toluene diisocyanate and acetone are mixed, tetraethylammonium bromide is added, and azobisisobutylamidine hydrochloride is added sequentially after stirring at room temperature Salt, 3-aminopropyltrimethoxysilane, polyurethane particles, and finally heated and stirred to obtain a polyurethane composite material. The material has the advantage of low processing temperature and is expected to be used in the manufacture of artificial organs. However, acetone is a volatile organic solvent, which is easy to cause harm to the human body during processing. At the same time, the mechanical strength of the product obtained by 3D printing of this material is not high.

The introduction of functional groups plays a decisive role in the performance of polymers, especially in use. For example, the Diels-Alder dynamic bond has environmental responsiveness and can respond to external stimuli, endowing the material with self-healing and self-adhesive properties. However, the application of polymers with functional groups in 3D printing has not been seen so far.

Contents of the invention

The object of the present invention is the polyurethane material for 3D printing, containing Diels-Alder bond and its preparation method and application developed for the deficiencies of the prior art, which is characterized in that the polyurethane material has a Diels-Alder dynamic bond corresponding to the environment, During the 3D printing process, when the temperature rises to the critical temperature, the Diels-Alder dynamic bond breaks and crosslinks, and the viscosity of the system decreases rapidly, which is beneficial to the laser sintering process; when the temperature decreases, the Diels-Alder dynamic bond is re-formed, making the system Cross-linking enhances the mechanical properties of the product, while the Diels-Alder dynamic bond endows the material with self-healing and self-adhesive properties.

The object of the present invention is achieved by the following technical measures, wherein the raw material parts are molar parts unless otherwise specified:

Starting materials for 3D printing polyurethane materials with dynamic bonds are made from the following components,

The diol chain extender containing Diels-Alder bond is matched with the diisocyanate trimer crosslinking agent to prepare polyurethane material containing Diels-Alder bond. The molecular structure of the polyurethane material contains dynamic chemical bond Diels-Alder bond, containing Diels - The polyurethane material of Alder bond has the function of self-healing and self-adhesive.

The diisocyanate is any one of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate and dicyclohexylmethane diisocyanate.

Described polyester polyol is polyethylene adipate, polyethylene glycol propylene glycol adipate, polyethylene glycol butylene adipate, polyethylene adipate, polyethylene ε- Any one of caprolactone, polyether polyol is polyether polyol-2000, polyether polyol-3000, polyether polyol-4000, polyether polyol-5000, polyether polyol-6000, polyether polyol Any one of polyol-7000 and polyether polyol-8000.

The diisocyanate trimer crosslinking agent is any one of hexamethylene diisocyanate trimer, toluene diisocyanate trimer, and diphenylmethane diisocyanate trimer.

The preparation method of polyurethane material containing Diels-Alder bond comprises the following steps:

1) Preparation of diols containing Diels-Alder bonds

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 12-36 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; The product III and the alcohol amine are reacted in an equimolar amount at a temperature of 65-80°C in excess methanol for 12-36 hours, and the reaction mixture is cooled and crystallized in a refrigerator, then subjected to suction filtration, washed with ether, and dried to obtain the product IV; The product IV was added to excess toluene, reflux reaction at a temperature of 100-125°C for 10-20 hours, then the solution was filtered and placed in a refrigerator to cool and crystallize, and the product V was obtained by suction filtration, ether washing and drying; equimolar amounts of Product V reacts with furfuryl alcohol at a temperature of 70-85°C in excess toluene for 12-36 hours, crushes the precipitate, filters it with suction, washes with ether, and dries to obtain product VI, which is a binary compound containing a Diels-Alder bond. alcohol;

2) Preparation of polyurethane containing Diels-Alder bond

Melt and react 100 parts of diisocyanate with 50-75 parts of polyester polyol or polyether polyol at a temperature of 70-100°C for 1-3 hours to obtain a prepolymer, and then add 0-50 parts of isocyanate trimer as a crosslinking agent , 50-125 parts of diols containing Diels-Alder bonds are used as chain extenders, and continue to react at a temperature of 70-90°C for 48-120 hours to obtain polyurethanes containing Diels-Alder bonds, and prepare them into particle sizes of 10-100 μm of powder.

The inolamine is any one of methanolamine, ethanolamine, n-propanolamine, isopropanolamine, 4-amino-n-butanol, 6-amino-n-hexanol and diglycolamine.

The polyurethane material is prepared into a powder material by any method of mechanical grinding, freeze pulverization, solvent precipitation or spray drying.

The polyurethane material containing Diels-Alder bond is used in any one of selective laser sintering technology, fusion deposition technology, photocuring molding technology or layered entity manufacturing technology in 3D printing technology.

Performance Testing:

The sample obtained in Application Example 1 is tested for mechanical properties, and the corresponding tensile strength, elongation at break, and Young's modulus are obtained, as shown in Table 1;

The sample obtained in Application Example 1 was cut off, and then the two sections were pasted together, and after being heated, irradiated with ultraviolet light or ultrasonically treated for a period of time, the fractured surface was bonded. Carry out mechanical property test to the sample after bonding, obtain corresponding tensile strength, elongation at break, Young's modulus, as shown in Table 2;

The present invention has the following advantages:

1. During the 3D printing process, when the temperature rises above the critical temperature, the Diels-Alder dynamic bond breaks, and the viscosity of the system decreases, which is beneficial to the 3D printing process;

2. The Diels-Alder dynamic bond reorganizes when the temperature is lower than the critical temperature, which makes the material system cross-linked and improves the mechanical properties of the product;

3. The Diels-Alder dynamic bond has environmental responsiveness, endowing 3D printing products with self-healing and self-adhesive properties;

4. The base material is polyurethane, which has good flexibility.

5. The material can be used in the preparation of artificial skin, artificial blood vessels and artificial cartilage.

detailed description

The present invention is specifically described below through the examples. It is necessary to point out that the present examples are only used to further illustrate the present invention, and can not be interpreted as limiting the protection scope of the present invention. Those skilled in the art can according to the above invention Some non-essential improvements and adjustments have been made to the content. Unless otherwise specified, the following parts are all molar parts.

Example 1

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 12 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; product III React with methanol amine in an equimolar amount at a temperature of 65°C in excess methanol for 12 hours, put the reaction mixture into the refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain the product IV; add the product IV to the excess In toluene, reflux reaction at a temperature of 100°C for 10h, then filter the solution and put it into a refrigerator to cool and crystallize, filter with suction, wash with ether, and dry to obtain the product Ⅴ; equimolar amounts of product Ⅴ and furfuryl alcohol at a temperature of 70°C, in React in excess toluene for 12 hours, mash the precipitate, filter with suction, wash with ether, and dry to obtain product VI, which is a diol containing a Diels-Alder bond;

100 parts of toluene diisocyanate and 50 parts of polyethylene adipate polyol were melted and reacted at a temperature of 70 ° C for 1 hour to obtain a prepolymer, and then 50 parts of diols containing Diels-Alder bonds were added as chain extenders. Continue to react at a temperature of 70° C. for 48 hours to obtain a polyurethane containing a Diels-Alder bond, and use a mechanical grinding method to make a powder with an average particle size of 60 μm.

Example 2

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 18 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; product III React with ethanolamine in an equimolar amount at a temperature of 68°C in excess methanol for 18 hours, put the reaction mixture in the refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain product IV; add product IV to excess toluene reflux reaction at a temperature of 105°C for 12h, then filter the solution and put it into a refrigerator for cooling and crystallization, and then obtain the product Ⅴ through suction filtration, washing with ether, and drying; React in toluene for 18 hours, crush the precipitate, filter with suction, wash with ether, and dry to obtain product VI, which is a diol containing Diels-Alder bond;

Melt 100 parts of toluene diisocyanate and 55 parts of polyethylene adipate polyol at a temperature of 75°C for 1.5 hours to obtain a prepolymer, and then add 10 parts of hexamethylene diisocyanate trimer as a crosslinking agent , 65 parts of diols containing Diels-Alder bonds are used as chain extenders, continue to react at a temperature of 75 ° C for 60 hours to obtain polyurethanes containing Diels-Alder bonds, and use mechanical grinding to make powders with an average particle size of 60 μm.

Example 3

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 24 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; product III React with propanolamine in an equimolar amount at a temperature of 71°C in excess methanol for 24 hours, put the reaction mixture in the refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain product IV; add product IV to excess in toluene at a temperature of 110°C for 14 hours, then filtered the solution and placed it in a refrigerator to cool and crystallize, and then filtered, washed with ether, and dried to obtain the product V; equimolar amounts of the product V and furfuryl alcohol at a temperature of 76°C, React in excess toluene for 24 hours, crush the precipitate, filter with suction, wash with ether, and dry to obtain product VI, which is a diol containing Diels-Alder bond;

100 parts of diphenylmethane diisocyanate and 60 parts of polyethylene adipate polyol were melted and reacted at a temperature of 80°C for 2 hours to obtain a prepolymer, and 20 parts of toluene diisocyanate trimer were added as a crosslinking agent. 80 parts of diols containing Diels-Alder bonds were used as chain extenders, and the reaction was continued at 80°C for 72 hours to obtain polyurethanes containing Diels-Alder bonds, which were then mechanically milled to produce a powder with an average particle size of 60 μm.

Example 4

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 30 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; product III React with an equimolar amount of isopropanolamine in excess methanol for 30 hours at a temperature of 74°C, put the reaction mixture in the refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain product IV; add product IV to In excess toluene, reflux reaction at a temperature of 115°C for 16h, then filter the solution and put it in a refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain product V; equimolar amounts of product V and furfuryl alcohol are mixed at a temperature of 79°C , reacted in excess toluene for 30 hours, smashed the precipitate, filtered it with suction, washed it with ether, and dried it to obtain the product VI, which is a diol containing a Diels-Alder bond;

Melt and react 100 parts of diphenylmethane diisocyanate and 65 parts of polyethylene adipate propylene glycol ester polyol at 85°C for 2.5 hours to obtain a prepolymer, and then add 30 parts of toluene diisocyanate trimer for crosslinking Agent, 95 parts of diols containing Diels-Alder bonds are used as chain extenders, continue to react at 85°C for 84 hours to obtain polyurethanes containing Diels-Alder bonds, and use mechanical grinding to make powders with an average particle size of 10 μm.

Example 5

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 36 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; product III React with 4-amino-n-butanol in an equimolar amount at a temperature of 77°C in excess methanol for 36 hours, put the reaction mixture into the refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain product IV; Add it to excess toluene, reflux reaction at a temperature of 120°C for 18h, then filter the solution and put it in the refrigerator to cool and crystallize, and then get the product V through suction filtration, ether washing and drying; React in excess toluene at 82°C for 36 hours, crush the precipitate, filter with suction, wash with ether, and dry to obtain product VI, which is a diol containing Diels-Alder bond;

Melt 100 parts of toluene diisocyanate and 70 parts of polyethylene adipate butylene glycol ester polyol at a temperature of 90°C for 3 hours to obtain a prepolymer, and then add 40 parts of diphenylmethane diisocyanate trimer As a cross-linking agent, 110 parts of diols containing Diels-Alder bonds are used as chain extenders. Continue to react at a temperature of 90°C for 96 hours to obtain polyurethanes containing Diels-Alder bonds, and use freeze grinding to make powders with an average particle size of 30 μm.

Example 6

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 24 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; product III React with 6-amino-n-hexanol in an equimolar amount at a temperature of 80°C in excess methanol for 24 hours, put the reaction mixture into the refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain the product IV; add the product IV to into excess toluene, reflux at a temperature of 125°C for 20 hours, then filter the solution and put it in a refrigerator to cool and crystallize, and then obtain product V through suction filtration, ether washing, and drying; equimolar amounts of product V and furfuryl alcohol are ℃, reacted in excess toluene for 24 hours, crushed the precipitate, filtered it with suction, washed it with ether, and dried it to obtain the product VI, which is a diol containing a Diels-Alder bond;

100 parts of diphenylmethane diisocyanate and 75 parts of polyhexamethylene adipate polyol were melted and reacted at a temperature of 70°C for 2 hours to obtain a prepolymer, and then 50 parts of diphenylmethane diisocyanate trimer were added to obtain Cross-linking agent, diol containing Diels-Alder bond is 125 parts of chain extender, continue to react at 70°C for 108h to obtain polyurethane containing Diels-Alder bond, and use freeze crushing method to make a powder with an average particle size of 80 μm.

Example 7

Dissolve equimolar amounts of furan and maleic anhydride in excess 1,4-dioxane, react at room temperature for 24 hours, smash the precipitate, filter with suction, wash with ether, and dry to obtain product III; product III React with diethylene glycol amine in an equimolar amount at a temperature of 75°C in excess methanol for 24 hours, put the reaction mixture into the refrigerator to cool and crystallize, then filter with suction, wash with ether, and dry to obtain the product IV; add the product IV to In excess toluene, reflux reaction at a temperature of 110°C for 15h, then filter the solution and put it in a refrigerator to cool and crystallize, and then obtain the product V by suction filtration, washing with ether, and drying; , reacted in excess toluene for 24 hours, smashed the precipitate, filtered it with suction, washed it with ether, and dried it to obtain the product VI, which is a diol containing a Diels-Alder bond;

Melt 100 parts of diphenylmethane diisocyanate and 75 parts of polyε-caprolactone polyol at a temperature of 80°C for 2 hours to obtain a prepolymer, then add 50 parts of diphenylmethane diisocyanate trimer as a crosslinking agent 125 parts of diols containing Diels-Alder bonds are used as chain extenders, and the reaction is continued at 80°C for 120h to obtain polyurethanes containing Diels-Alder bonds, which are made into powders with an average particle size of 100 μm by freeze grinding.

Application example 1

Spread the polyurethane powder material containing Diels-Alder dynamic bonds prepared in Examples 1 to 3 on the workbench of the 3D printer, set the temperature of the build cylinder to 95°C, the laser power to 60w, and the scanning distance to 0.2mm, and spread the powder Thickness 0.15mm, scanning speed 7.6m/s;

Under the control of computer-related programs, the laser selectively scans and sinters the polyurethane material powder containing Diels-Alder dynamic bonds according to the cross-section data of layered slices in the vertical direction according to the three-dimensional stl file;

The polyurethane material powder containing the Diels-Alder dynamic bond in the area scanned by the laser is heated and melted, and at the same time the Diels-Alder dynamic bond is broken, the viscosity of the material is greatly reduced, and bonding occurs. After the sintering of one layer is completed, the working cylinder is lowered to the set height, and then the next layer is powdered and sintered, and bonded with the previous layer, so that it is repeatedly processed and shaped. After laser sintering and cooling, the material solidifies and the Diels-Alder dynamic bonds recombine to cross-link the material system. Finally, take it out for powder cleaning and grinding to obtain a polyurethane product containing Diels-Alder dynamic bonds, which has excellent mechanical properties and has self-repairing and self-adhesive properties.

Table 1. The mechanical properties of the 3D printed samples of the materials obtained in Examples 1 to 3

It can be seen from Table 1 that the samples prepared by 3D printing of the polyurethane have excellent mechanical properties. It has excellent mechanical properties, the tensile strength is 13.02MPa, and the elongation at break can reach 413.35%, indicating that the material has good flexibility

Table 2. The mechanical properties of the materials obtained in Examples 1 to 3 after cutting and bonding the 3D printed samples

It can be seen from Table 2 that the mechanical properties of the samples obtained by 3D printing of the polyurethane material can still be maintained at a relatively high level after cutting and self-adhesive treatment, indicating that the material has good self-adhesive and self-repairing properties.

Claims (8)

1. a kind of be used for 3D printing, the polyurethane material of the key containing Diels-Alder, it is characterised in that the starting of the polyurethane material Raw material is made up of following components, is calculated as by molfraction：

The glycol chain extender of the key containing Diels-Alder matches preparation with diisocyanate trimer crosslinking agent and contains Diels- Contain dynamic chemical key Diels-Alder keys in Alder key polyurethane materials, the molecular structure for the polyurethane material being made, contain The polyurethane material of Diels-Alder keys has the function of selfreparing and autoadhesion.

2. it is used for 3D printing, the polyurethane material of the key containing Diels-Alder according to claim 1, it is characterised in that two is different Cyanate is that toluene di-isocyanate(TDI), methyl diphenylene diisocyanate, XDI, hexa-methylene two are different Any of cyanate, dicyclohexyl methyl hydride diisocyanate.

3. it is used for 3D printing, the polyurethane material of the key containing Diels-Alder according to claim 1, it is characterised in that polyester Polyalcohol be polyethylene glycol adipate, polyadipate ethylene glycol propylene glycol ester, polyadipate ethylene glycol butanediol ester, gather oneself two Any in sour hexylene glycol ester, poly-epsilon-caprolactone, PPG is PPG -2000, PPG -3000, gathered Ethoxylated polyhydric alcohol -4000, PPG -5000, PPG -6000, PPG -7000, PPG -8000 In it is any.

4. it is used for 3D printing, the polyurethane material of the key containing Diels-Alder according to claim 1, it is characterised in that two is different Cyanate trimer crosslinker is hexamethylene diisocyanate trimer, toluene diisocyanate trimer, diphenyl methane Any of diisocyanate trimer.

5. being used for 3D printing, the preparation method of the polyurethane material of the key containing Diels-Alder according to claim 1, it is special Levy and be that the preparation method of the polyurethane material of key containing Diels-Alder comprises the following steps：

1) preparation of the dihydric alcohol of key containing Diels-Alder

Furans and maleic anhydride equimolar amounts are dissolved in excessive Isosorbide-5-Nitrae-dioxane, 12~36h is being reacted at room temperature, will be heavy Starch is smashed to pieces, through suction filtration, ether washing, drying, obtains product III；Product III and hydramine equimolar amounts in 65~80 DEG C of temperature, 12~36h is reacted in excessive methanol, reaction mixture is put into refrigerator crystallisation by cooling, then through suction filtration, ether washing, baking It is dry, obtain product IV；Product IV is added in excessive toluene, in 100~125 DEG C of 10~20h of back flow reaction of temperature, then Refrigerator crystallisation by cooling is put into after solution is filtered, through suction filtration, ether washing, drying, product V is obtained；The product V of equimolar amounts With furfuryl alcohol in 70~85 DEG C of temperature, 12~36h is reacted in excess toluene, sediment is smashed to pieces, through suction filtration, ether washing, dried It is dry, product VI is obtained, is the dihydric alcohol of the key containing Diels-Alder；

2) preparation of the polyurethane of key containing Diels-Alder

By 100 parts of diisocyanate and 50~75 parts of PEPAs or PPG, in 70~100 DEG C of frit reactions of temperature 1~3h obtains performed polymer, and it is crosslinking agent, the dihydric alcohol 50 of the key containing Diels-Alder to add 0~50 part of isocyanate trimer ~125 parts are chain extender, continue, in 70~90 DEG C of 48~120h of reaction of temperature, to obtain the polyurethane of key containing Diels-Alder, and will It is prepared into the powder that particle diameter is 10~100 μm.

6. being used for 3D printing, the preparation method of the polyurethane material of the key containing Diels-Alder according to claim 5, it is special Levy and be that hydramine is carbinolamine, monoethanolamine, normal propyl alcohol amine, isopropanolamine, 4- amino n-butanol, 6- amino n-hexyl alcohol and diethylene glycol (DEG) It is any in amine.

7. it is used for 3D printing, the polyurethane material of the key containing Diels-Alder according to claim 1, it is characterised in that described Polyurethane material is prepared into by any method in mechanical milling method, Freezing smashing method, solvent precipitation or spray drying process Dusty material.

8. according to claim 1 be used for 3D printing, the purposes of the polyurethane material of the key containing Diels-Alder, its feature Be polyurethane material of the key containing Diels-Alder containing dynamic key be used for 3D printing technique in Selective Laser Sintering, Any of fusion sediment technology, Stereolithography technology or layer separated growth technology.