A polythiourethane urea-ketone polymer, its synthesis method and application

Abstract

This invention belongs to the fields of polymer synthesis and materials science, specifically disclosing a polythiourethane urea-ketone polymer, its synthesis method, and applications. Under alkaline catalysis, the anionic copolymerization reaction of elemental sulfur and isocyanate is achieved. The prepared product, when coated onto a substrate material, can be cured at room temperature to obtain a polythiourethane urea-ketone coating. This method has advantages such as low catalyst usage, mild reaction conditions, wide monomer compatibility, simple operation, and low monomer cost. The prepared polythiourethane urea-ketone exhibits good chemical and thermal stability, along with excellent UV resistance and a high refractive index, making it suitable for applications in optical coatings, optical lenses, and UV-resistant coatings.

Description

Technical Field

[0001] This invention belongs to the fields of polymer synthesis and materials science, and specifically discloses a polythiourethane urea-ketone polymer, its synthesis method, and its applications. Background Technology

[0002] Polyurethane thiocyanates, as a traditional polymer material, are widely used in high-performance adhesives, sealants, anti-corrosion coatings, and optical materials. The thioisocyanate structure within its composition provides better chain flexibility, significantly improving its adhesion to substrate surfaces. Furthermore, the introduction of sulfur also contributes to the superior optical properties of related coatings and adhesives.

[0003] Traditional methods for preparing polysulfuron materials mainly involve the stepwise polymerization of dimercapto monomers and diisocyanate monomers to form polysulfuron; alternatively, methods include the condensation polymerization of pentathiocarbonate and diamine monomers; ring-opening copolymerization of carbonyl sulfide and aziridine; and multi-component copolymerization reactions of sulfur, diisocyanate, and diol. However, the monomers used in existing synthesis methods, such as dimercapto monomers, thiocarbonates, and diisocyanates, have high production costs, while aziridine and carbonyl sulfide present operational difficulties during synthesis. Therefore, there is a need for a novel, efficient, simple, easy-to-operate, and low-cost method for synthesizing polysulfuron materials. Summary of the Invention

[0004] To address the shortcomings of existing polythiourethane synthesis routes, this invention proposes a one-step method for synthesizing polythiourethane urea-ketone prepolymers via a catalytic direct reaction of elemental sulfur with isocyanate monomers and anionic copolymerization under mild conditions. The prepolymers can be directly cured into films and bonded to substrates to form novel functionalized coatings with refractive and UV-resistant properties. This method offers advantages such as using a small amount of catalyst, mild reaction conditions, broad monomer compatibility, simple operation, and low monomer cost.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] The composition of the polyurethane urea-ketone prepolymer by mass percentage is: 83-95 wt% isocyanate, 3-15 wt% elemental sulfur, and 0.5-2.0 wt% alkali catalyst.

[0007] The isocyanate monomer is one or more of the following: benzyl isocyanate (BI), n-butyl isocyanate (n-BIC), hexamethylene diisocyanate (HDI), toluene diisocyanate (MDI), and isoflavone diisocyanate (IPDI).

[0008] The base catalysts are 1,8-diazobispirocyclo[5.4.0]undec-7-ene (DBU) and 1,5-7-triazidobicyclo(4.4.0)dec-5-ene (TBD).

[0009] This invention also provides a method for synthesizing polythiourethane urea-ketone polymers, which uses anionic copolymerization to prepare polythiourethane urea-ketone prepolymers. Specifically, isocyanate monomers and elemental sulfur are reacted in a mild environment in the presence of an alkaline catalyst to obtain a prepolymer, which is then cured to obtain polythiourethane urea-ketone polymers.

[0010] The copolymerization reaction environment is a dry environment protected by inert gas, the copolymerization reaction temperature is 25℃, and the copolymerization reaction time is 6-24h.

[0011] The above-mentioned polythiourethane urea-ketone prepolymers are used to prepare optical coatings, optical lenses, and UV-resistant coatings. The specific preparation method of the coating is as follows: the polythiourethane urea-ketone prepolymer is cast and cured on a substrate material.

[0012] The base material is stainless steel, metal, general-purpose plastic or plexiglass.

[0013] The curing conditions are: room temperature curing, curing time is 8-24 hours.

[0014] Beneficial effects:

[0015] The method for synthesizing polythiourethane urea-ketone polymers provided by this invention is a one-step synthesis with mild reaction conditions, which greatly reduces the operational difficulty, time, and economic costs of polymer synthesis. Furthermore, it allows for a wide range of selectable monomers, with functionalized isocyanates all suitable as reactants for copolymerization.

[0016] The polythiourethane urea-ketone coating prepared by this invention has good mechanical properties, adhesion properties, and good thermal and chemical stability. Attached image description:

[0017] Figure 1 This is a schematic diagram of the adhesion performance test.

[0018] Figure 2 The figure shows the mass loss of the coating prepared in Example 1 after immersion in acidic and alkaline methanol solutions and dimethyl sulfoxide solutions for seven days.

[0019] Figure 3 The UV-Vis spectra of the polyurethane urea-ketone prepared in Examples 1 and 2 are compared with those of ordinary PET films.

[0020] Figure 4 XRD tests were performed on the polythiourethane urea ketone and elemental sulfur prepared in Example 5.

[0021] Figure 5 TGA test of the polythiourethane urea ketone prepared in Example 6.

[0022] Figure 6 The FT-IR spectrum of the polythiourethane urea ketone prepared in Example 1 is shown. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] Weigh 0.48g of elemental sulfur powder, 5.046g of HDI, and 0.0372g of TBD into a 10mL flask. Mix and stir at room temperature for 24h under inert gas protection. After the reaction is complete, a prepolymer is obtained with a yield of 99%. Cast the prepolymer mixture onto a substrate (316L stainless steel) and cure it at room temperature for 24h.

[0026] The cured coating film was subjected to degradation experiments in acidic methanol, alkaline methanol, and benzyl mercaptan solutions, respectively. The mass loss of Example 1 was measured after seven days, and the results are as follows: Figure 2 .

[0027] Figure 3 The UV-Vis spectra of the polyurethane urea-ketone coatings prepared in Examples 1 and 2 are compared with those of ordinary PET films, demonstrating that their UV resistance is stronger than that of traditional optical materials.

[0028] Example 2

[0029] 0.96 g of elemental sulfur powder, 5.046 g of HDI, and 0.0372 g of TBD were weighed into a 10 mL flask and mixed and stirred at room temperature for 24 h under inert gas protection. After the reaction was completed, a prepolymer was obtained with a yield of 99%. The prepolymer mixture was cast onto a substrate (316L stainless steel) and cured at room temperature for 24 h.

[0030] Performance testing was conducted at room temperature.

[0031] According to the ASTM D1002 test standard, polyurethane urea-ketone prepolymer was applied to the surfaces of two 2cm × 2cm substrates (316L stainless steel) and bonded together. After curing, the adhesion was tested. Figure 1 .

[0032] The performance is shown in Table 1.

[0033] Example 3

[0034] Weigh 0.16g of elemental sulfur powder, 1.682g of HDI, and 0.0139g of TBD into a 10mL flask. Mix and stir at room temperature for 12h under inert gas protection. After the reaction is complete, a prepolymer is obtained with a yield of 99%. Cast the prepolymer mixture onto a substrate (316L stainless steel) and cure it at room temperature for 12h.

[0035] Example 4

[0036] Weigh 0.16g of elemental sulfur powder, 1.682g of HDI, 1.092g of BI, and 0.0139g of TBD into a 10mL flask. Mix and stir at room temperature for 24h under inert gas protection. After the reaction is complete, a prepolymer is obtained with a yield of 85%. Cast the prepolymer mixture onto a substrate (316L stainless steel) and cure it at room temperature for 24h.

[0037] Example 5

[0038] Weigh 0.16g of elemental sulfur powder, 1.682g of HDI, 1.092g of n-BIC, and 0.0139g of DBU into a 10mL flask. Mix and stir at room temperature for 24h under inert gas protection. After the reaction is complete, a prepolymer is obtained with a yield of 80%. Cast the prepolymer mixture onto a substrate (316L stainless steel) and cure it at room temperature for 24h.

[0039] Example 6

[0040] Weigh 0.32g of elemental sulfur powder, 3.251g of MDI, and 0.0372g of DBU into a 10mL flask. Mix and stir at room temperature for 12h under inert gas protection. After the reaction is complete, a prepolymer is obtained with a yield of 80%. Cast the prepolymer mixture onto a substrate (316L stainless steel) and cure it at room temperature for 24h.

[0041] Example 7

[0042] Weigh 0.32g of elemental sulfur powder, 3.251g of IPDI, and 0.0372g of DBU into a 10mL flask. Mix and stir at room temperature for 12h under inert gas protection. After the reaction is complete, a prepolymer is obtained with a yield of 80%. Cast the prepolymer mixture onto a substrate and cure it at room temperature for 24h.

[0043] Example 8

[0044] Weigh 0.32g of elemental sulfur powder, 3.251g of HDI, and 0.0372g of DBU into a 10mL flask. Mix and stir at room temperature for 24h under inert gas protection. After the reaction is complete, a prepolymer is obtained with a yield of 89%. Cast the prepolymer mixture onto a substrate (316L stainless steel) and cure it at room temperature for 24h.

[0045] Comparative Example 1

[0046] 0.96 g of elemental sulfur powder, 5.046 g of BDDA (1,4-butanediol diacrylate), and 0.0372 g of TBD were weighed into a 10 mL flask and mixed and stirred at room temperature for 24 h under inert gas protection. After the reaction was completed, a prepolymer was obtained with a yield of 79%. The prepolymer mixture was cast onto a substrate (316L stainless steel) and cured at room temperature for 24 h.

[0047] Table 1. Tensile, adhesive, and refractive properties of the embodiments.

[0048] Example Tensile strength (MPa) Elongation at break (%) Adhesion force (MPa) Refractive index 1 10.2±1.82 95.84±6.05 1.17±0.12 1.5838 2 12.53±2.78 95.76±5.09 1.08±0.10 1.5717 3 11.56±2.28 105.23±7.34 0.91±0.13 1.5263 4 9.15±1.38 118.23±5.05 0.93±0.31 1.5282 5 8.96±2.71 113.89±6.05 1.19±0.20 1.5128 6 50.21±3.48 7.78±0.25 0.54±0.09 1.4323 7 40.89±2.32 6.98±1.31 0.61±0.08 1.2756 8 12.61±0.16 103.83±3.68 1.08±0.17 1.5123 Comparative Example 1 8.6±1.23 85.32±1.06 0.32±0.06 1.5326 Polysulfuric acid 3.68±1.11 896±15.23 / /

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A polythiourethane urea-ketone polymer, characterized in that, The raw materials for preparing polythiourethane urea-ketone polymers consist of the following composition by mass percentage: 83-95 wt% isocyanate monomer, 3-15 wt% elemental sulfur, and 0.5-2.0 wt% alkaline catalyst. The isocyanate monomer is one or more of hexamethylene diisocyanate (HDI), toluene diisocyanate (MDI), and isophorone diisocyanate (IPDI).

2. The polythiourethane urea-ketone polymer according to claim 1, characterized in that, The alkaline catalyst is 1,8-diazobispiro[5.4.0]undec-7-ene DBU or 1,5,7-triazidobicyclo(4.4.0)dec-5-ene TBD.

3. A method for synthesizing the polythiourethane urea-ketone polymer according to claim 1, characterized in that, The synthesis method is as follows: isocyanate monomer and elemental sulfur are reacted in the presence of an alkaline catalyst under an inert gas-protected dry environment to generate polythiourethane urea-ketone prepolymer, which is then cured to obtain polythiourethane urea-ketone polymer.

4. An application of the polythiourethane urea-ketone polymer according to claim 1, characterized in that, The polythiourethane urea-ketone polymer is used to prepare optical coatings, optical lenses, or UV-resistant coatings.

5. The application of the polythiourethane urea-ketone polymer according to claim 4, characterized in that, The coating is prepared by casting and curing a polythiourethane urea-ketone prepolymer onto a substrate material.

6. The application of the polythiourethane urea-ketone polymer according to claim 5, characterized in that, The matrix material is a metal or a general-purpose plastic.

7. The application of the polythiourethane urea-ketone polymer according to claim 5, characterized in that, The curing conditions are: room temperature curing, and curing time is 8-24 hours.

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