Siloxane-modified bio-based epoxy glass polymer material and preparation method thereof

Abstract

The invention provides a brand-new siloxane-modified bio-based epoxy glass polymer material and a preparation method thereof, vanillin reacts with different diamine compounds to prepare a vanillyl diphenol compound, the diphenol compound reacts with different epoxides to obtain a vanillyl epoxy compound, and the vanillyl epoxy glass polymer material is prepared from the vanillyl diphenol compound and the vanillyl epoxy compound. 3-aminopropyl triethoxy siloxane is introduced on this basis for cross-linking curing, the epoxy glass polymer material is prepared through a gradient heating curing method, and a large number of dynamic imine bonds and silicon-oxygen bonds in the material can enhance the mechanical property, thermal stability and creep resistance of the epoxy glass polymer. Besides, the experimental raw materials in the design are green and environment-friendly, and the epoxy glass high polymer material is excellent in mechanical property, thermal stability and creep resistance, is an excellent option for preparing green materials, and provides a thought for preparing the epoxy glass high polymer material by using a green method subsequently.

Description

Technical Field

[0001] The invention relates to the field of polymer material industry, and in particular to a bio-based epoxy glass polymer material modified by siloxane and a preparation method thereof. Background Art

[0002] At present, epoxy self-healing is the most studied system in self-healing chemistry. Epoxy self-healing is generally formed by cross-linking epoxy-containing compounds with amine or anhydride curing agents. The cured epoxy self-healing has excellent mechanical properties, heat resistance, chemical resistance and dimensional stability. However, most reported epoxy self-healing uses petrochemical products as raw materials. As people's sustainable development concept and environmental awareness gradually improve, biomass resources have received more and more attention. Bio-based polymer materials are a class of sustainable polymer materials synthesized from renewable resources through physical, chemical or biological processes. At present, some polymer materials based on biomass resources such as vegetable oil, vanillin, eugenol, mushroom ene and isosorbide have been widely reported. Bio-based epoxy resins have attracted more and more attention due to their advantages such as easy availability, low price and biodegradability. Siloxane groups have attracted much attention due to their unique properties such as low glass transition, high failure strain, low surface energy and excellent thermal stability brought by siloxane bonds.

[0003] Glass-like polymer materials are based on the combination of covalent adaptive networks, and the network topology structure formed by dynamic covalent cross-linking forms covalent adaptive networks (CANs), which combine the advantages of thermosetting materials and thermoplastic materials. Dynamic covalent bonds are a type of chemical bonds that undergo reversible breakage and reconstruction under specific external stimuli, so that thermosetting materials can be reprocessed and recycled. Glassy polymers are expected to solve the environmental pollution and resource waste caused by the inability to recycle traditional thermosetting polymers. Because this material can undergo network rearrangement under external stimuli, it can exhibit the characteristics of reprocessability, reshaping, plastic deformation, and shape memory. However, the preparation reaction process of existing glass-like polymer materials is not environmentally friendly, and the method of using vanillin to prepare epoxy glass-like polymer materials has not been disclosed in this research field. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a bio-based epoxy glass polymer material modified by siloxane and a preparation method thereof, based on a bisphenol compound generated from vanillin, which has excellent mechanical properties and is a bio-based, green epoxy glass polymer material with good mechanical properties, providing a new idea for the preparation of epoxy glass polymer materials.

[0005] The present invention is achieved through the following technical solutions: A method for preparing a bio-based epoxy glass polymer material modified by siloxane, characterized by comprising: S1, dissolving a diamine compound and vanillin in methanol, heating in a water bath under a nitrogen atmosphere for reaction, and post-treating the obtained product to obtain a vanillyl diphenol compound; S2, dissolving the vanillyl diphenol compound and the epoxy compound in DMF, and heating the mixture in an oil bath under a nitrogen atmosphere to obtain a preliminary prepolymer; S3, adding 3-aminopropyl triethoxysiloxane to the preliminary prepolymer for reaction, adding KOH after a period of reaction, and when the solution becomes viscous or bubbles emerge, the reaction is completed to prepare a bio-based epoxy glass polymer material; Preferably, the molar ratio of the diamine compound to vanillin in S1 is 1:2, and the total added amount of the diamine compound and vanillin in S1 accounts for 20 wt%-60 wt% of methanol.

[0006] Preferably, the molar ratio of the active H of the vanillyl diphenol compound to the epoxy group of the epoxy compound in S2 is 1:1.

[0007] Preferably, the molar ratio of the epoxy group of the vanillyl epoxy compound to the active H of 3-aminopropyltriethoxysiloxane in S3 is 1:1.

[0008] Preferably, the reaction temperature in S1 is 70°C and the reaction time is 6h, the reaction temperature in S2 is 90-120°C and the reaction time is 3-5h; the reaction temperature in S3 is 120-130°C and the reaction time is 1-2h.

[0009] Preferably, the diamine compound includes one of hexamethylenediamine, p-phenylenediamine and 4,4'-diaminodiphenylmethane.

[0010] Preferably, the epoxy compound is one of propylene triglycidyl ether epichlorohydrin.

[0011] Preferably, the curing temperature and time of the bio-based epoxy glass polymer material obtained in S3 are pre-curing at 60°C for 2h, curing at 80°C for 3h, and post-curing at 120°C for 1h.

[0012] Preferably, after the prepolymer initially synthesized in S3 is added to 3-aminopropyl triethoxysiloxane oil bath for a period of time, KOH is added to catalyze the formation of Si-O-Si bonds. When the solution becomes viscous or bubbles emerge, the reaction is completed to prepare a bio-based epoxy glass polymer material.

[0013] A method for preparing a bio-based epoxy glass polymer material modified by siloxane is prepared by the above-mentioned preparation method.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a new preparation method of a bio-based epoxy glass polymer material containing silicon-oxygen bonds, using readily available vanillin as a basic raw material, reacting with different diamine compounds to prepare a vanillyl diphenol compound, reacting the diphenol compound with an epoxy compound to obtain a vanillyl epoxy compound, on which 3-aminopropyl triethoxysiloxane is introduced for curing, and a bio-based, recyclable, and ductile epoxy glass polymer material is prepared by a gradient temperature curing method, a large number of dynamic imine bonds and silicon-oxygen bonds in the material can enhance the mechanical properties, thermal stability, and creep resistance of the epoxy glass polymer, the benzene ring structure in the vanillyl diphenol compound can increase the rigidity and thermal stability of the material, and the longer flexible chain segment in the coupling agent can give the material soft and tensile properties. In addition, the experimental raw materials in the design of the present invention are green and environmentally friendly, and the mechanical properties, thermal stability, and creep resistance of the epoxy glass polymer material are excellent, which is an excellent option for preparing green materials, and provides ideas for the subsequent use of green methods to prepare epoxy glass polymer materials.

[0015] Furthermore, the present invention enhances the mechanical properties and thermal stability of epoxy glass polymer materials by introducing imine bonds through homemade vanillyl epoxy compounds. The use of plant-based materials makes the obtained epoxy glass polymer materials have excellent biodegradability. Through the dynamic reversible reaction involving biomass, imine bond exchange and silicon-oxygen bond exchange reactions are obtained, which endows the glass polymer materials with the characteristics of repeatable processing and recyclability. This work promotes the types of epoxy glass polymers, making them promising candidates for repairable and recyclable adhesives. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a reaction process diagram of Example 1 to Example 3; Figure 2 It is a reaction process diagram of Example 4 to Example 6. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0018] The invention prepares a bio-based glass-like polymer material containing silicon-oxygen bonds by modification based on siloxane compounds.

[0019] The technical scheme adopted by the present invention is as follows: the first step is to add diamines and vanillin in a molar ratio of 1:2 to a three-necked flask equipped with an electric stirrer, a pure nitrogen protection device inlet, and a reflux condenser, and then methanol is added, and the reaction is carried out in a water bath at 70°C. After the reaction for 4-6 hours, the obtained product is filtered, and then recrystallized three times with methanol, and dried to obtain the product vanillyl diphenol compound. The second step is to take a vanillyl diphenol compound and an epoxy compound with a molar ratio of 1:1, dissolve them in DMF, and add them to a 250 mL three-necked flask equipped with a reflux condenser, an electric stirrer, and a thermometer. At 90-120°C, react for 3-5 hours to obtain a preliminary prepolymer. The third step is to add 3-aminopropyl triethoxysiloxane to the preliminary prepolymer for reaction, and after a period of reaction, add KOH. When the solution becomes viscous or bubbles emerge, the reaction is terminated to prepare a bio-based epoxy glass polymer material.

[0020] The diamine substance is one of hexamethylenediamine, p-phenylenediamine and 4,4'-diaminodiphenylmethane.

[0021] The epoxy compound is one of glycerol triglycidyl ether and epichlorohydrin.

[0022] The obtained bio-based epoxy glass polymer material has a curing temperature and a curing time of 50°C for pre-curing for 2 hours, 80°C for curing for 3 hours, and 120°C for post-curing for 1 hour.

[0023] Reaction equation: 1. Reaction equation of vanillyl diphenol compounds

[0024] Embodiment 1: like Figure 1 As shown, step 1: 60.8 g (0.4 mol) of vanillin and 21.6 g (0.2 mol) of p-phenylenediamine were dissolved in 70 mL and 30 mL of methanol, respectively. Then, they were added to a three-necked flask equipped with an electric stirrer, a pure nitrogen protection device inlet, and a reflux condenser, and reacted in a 70 ° C water bath. After reacting for 6 hours, the obtained product was filtered to obtain yellow crystals, which were then washed three times with methanol and dried to finally obtain the product vanillyl diphenol compound.

[0025] Step 2: Dissolve 28.2 g (0.075 mol) of vanillyl diphenol compound and 26.0 g (0.1 mol) of propylene glycol triglycidyl ether in 100 mL of DMF, add into a 250 mL three-necked flask with a stirring device, and react in an oil bath at 90-120°C for 5 hours to obtain a preliminary prepolymer.

[0026] Step 3: Add 16.6 g (0.075 mol) of 3-aminopropyltriethoxysiloxane to the preliminary prepolymer, heat to 130 °C and react for 1 hour, add KOH, stir manually, and when the solution becomes viscous or bubbles emerge, the reaction is over, and quickly pour the reaction mixture into a polytetrafluoroethylene (PTFE) mold for curing.

[0027] Step 4: The reaction mixture is pre-cured at 50°C for 2 hours, cured at 80°C for 3 hours, and post-cured at 120°C for 1 hour, to finally obtain a bio-based epoxy glass polymer film.

[0028] Embodiment 2: like Figure 1 As shown, step 1: 60.8 g (0.4 mol) of vanillin and 23.2 g (0.2 mol) of hexamethylenediamine were dissolved in 70 mL and 30 mL of methanol, respectively. Then, they were added into a three-necked flask equipped with an electric stirrer, a pure nitrogen protection device inlet, and a reflux condenser, and reacted in a water bath at 70 ° C. After reacting for 6 hours, the obtained product was filtered to obtain yellow crystals, which were then washed three times with methanol and dried to finally obtain the product vanillyl diphenol compound.

[0029] Step 2: Dissolve 28.8 g (0.075 mol) of vanillyl diphenol compound and 26.0 g (0.1 mol) of propylene glycol triglycidyl ether in 100 mL of DMF, add into a 250 mL three-necked flask with a stirring device, and react in an oil bath at 90-120°C for 5 hours to obtain a preliminary prepolymer.

[0030] Step 3: Add 16.6 g (0.075 mol) of 3-aminopropyltriethoxysiloxane to the preliminary prepolymer, heat to 130°C and react for 1 hour, add KOH, stir manually, and when the solution becomes viscous or bubbles emerge, the reaction is over, and quickly pour the reaction mixture into a polytetrafluoroethylene (PTFE) mold for curing.

[0031] Step 4: The reaction mixture is pre-cured at 50°C for 2 hours, cured at 80°C for 3 hours, and post-cured at 120°C for 1 hour, to finally obtain a bio-based epoxy glass polymer film.

[0032] Embodiment three: like Figure 1As shown, step 1: 60.8 g (0.4 mol) of vanillin and 39.6 g (0.2 mol) of 4,4'-diaminodiphenylmethane were dissolved in 70 mL and 30 mL of methanol, respectively. Then, they were added to a three-necked flask equipped with an electric stirrer, a pure nitrogen protection device inlet, and a reflux condenser, and reacted in a 70 ℃ water bath. After 6 hours of reaction, the obtained product was filtered to obtain yellow crystals, which were then washed three times with methanol and dried to finally obtain the product vanillyl diphenol compound.

[0033] Step 2: Dissolve 34.95 g (0.075 mol) of vanillyl diphenol compound and 26.0 g (0.1 mol) of propylene glycol triglycidyl ether in 100 mL of DMF, add into a 250 mL three-necked flask with a stirring device, and react in an oil bath at 90-120°C for 5 hours to obtain a preliminary prepolymer.

[0034] Step 3: Add 16.6 g (0.075 mol) of 3-aminopropyltriethoxysiloxane to the preliminary prepolymer, heat to 130 °C and react for 1 hour, add KOH, stir manually, and when the solution becomes viscous or bubbles emerge, the reaction is over, and quickly pour the reaction mixture into a polytetrafluoroethylene (PTFE) mold for curing.

[0035] Step 4: The reaction mixture is pre-cured at 50°C for 2 hours, cured at 80°C for 3 hours, and post-cured at 120°C for 1 hour, to finally obtain a bio-based epoxy glass polymer film.

[0036] Embodiment 4: like Figure 2 As shown, step 1: 60.8 g (0.4 mol) of vanillin and 21.6 g (0.2 mol) of p-phenylenediamine were dissolved in 70 mL and 30 mL of methanol, respectively. Then, they were added to a three-necked flask equipped with an electric stirrer, a pure nitrogen protection device inlet, and a reflux condenser, and reacted in a 70 ° C water bath. After reacting for 6 hours, the obtained product was filtered to obtain yellow crystals, which were then washed three times with methanol and dried to finally obtain the product vanillyl diphenol compound.

[0037] Step 2: 11.28 g (0.03 mol) of vanillyl diphenol compound, 55.2 g (0.06 mol) of epichlorohydrin and 0.72 g (0.003 mol) of tetrabutylammonium bromide were added to a three-necked flask and reacted at 85 °C for 4 hours. Thereafter, the temperature was lowered to 50 °C, and then 10.92 g (0.06 mol) of NaOH solution was added to the flask, and the reaction was continued for 3 hours. After the reaction was completed, the excess epichlorohydrin was removed, and the residue was washed with deionized water and dried in a freeze dryer overnight to obtain a vanillyl epoxy compound.

[0038] Step 3: Add 3-aminopropyl triethoxysiloxane to the vanillyl epoxy compound, heat to 130 °C and react for 1 hour, add KOH, stir manually, and when the solution becomes viscous or bubbles emerge, the reaction is over, and quickly pour the reaction mixture into a polytetrafluoroethylene (PTFE) mold for curing.

[0039] Step 4: The reaction mixture is pre-cured at 50°C for 2 hours, cured at 80°C for 3 hours, and post-cured at 120°C for 1 hour, to finally obtain a bio-based epoxy glass polymer film.

[0040] Embodiment five: like Figure 2 As shown, step 1: 60.8 g (0.4 mol) of vanillin and 23.2 g (0.2 mol) of hexamethylenediamine were dissolved in 70 mL and 30 mL of methanol, respectively. Then, they were added into a three-necked flask equipped with an electric stirrer, a pure nitrogen protection device inlet, and a reflux condenser, and reacted in a water bath at 70 ° C. After reacting for 6 hours, the obtained product was filtered to obtain yellow crystals, which were then washed three times with methanol and dried to finally obtain the product vanillyl diphenol compound.

[0041] Step 2: 11.52 g (0.03 mol) of vanillyl diphenol compound, 55.2 g (0.06 mol) of epichlorohydrin and 0.72 g (0.003 mol) of tetrabutylammonium bromide were added to a three-necked flask and reacted at 85 °C for 4 hours. Thereafter, the temperature was lowered to 50 °C, and then 10.92 g (0.06 mol) of NaOH solution was added to the flask, and the reaction was continued for 3 hours. After the reaction was completed, the excess epichlorohydrin was removed, and the residue was washed with deionized water and dried in a freeze dryer overnight to obtain a vanillyl epoxy compound.

[0042] Step 3: Add 3-aminopropyl triethoxysiloxane to the vanillyl epoxy compound, heat to 130 °C and react for 1 hour, add KOH, stir manually, and when the solution becomes viscous or bubbles emerge, the reaction is over, and quickly pour the reaction mixture into a polytetrafluoroethylene (PTFE) mold for curing.

[0043] Step 4: The reaction mixture is pre-cured at 50°C for 2 hours, cured at 80°C for 3 hours, and post-cured at 120°C for 1 hour, to finally obtain a bio-based epoxy glass polymer film.

[0044] Embodiment six: like Figure 2As shown, step 1: 60.8 g (0.4 mol) of vanillin and 39.6 g (0.2 mol) of 4,4'-diaminodiphenylmethane were dissolved in 70 mL and 30 mL of methanol, respectively. Then, they were added to a three-necked flask equipped with an electric stirrer, a pure nitrogen protection device inlet, and a reflux condenser, and reacted in a 70 ℃ water bath. After 6 hours of reaction, the obtained product was filtered to obtain yellow crystals, which were then washed three times with methanol and dried to finally obtain the product vanillyl diphenol compound.

[0045] Step 2: 13.98 g (0.03 mol) of vanillyl diphenol compound, 55.2 g (0.06 mol) of epichlorohydrin and 0.72 g (0.003 mol) of tetrabutylammonium bromide were added to a three-necked flask and reacted at 85 °C for 4 hours. Thereafter, the temperature was lowered to 50 °C, and then 10.92 g (0.06 mol) of NaOH solution was added to the flask, and the reaction was continued for 3 hours. After the reaction was completed, the excess epichlorohydrin was removed, and the residue was washed with deionized water and dried in a freeze dryer overnight to obtain a vanillyl epoxy compound.

[0046] Step 3: Add 3-aminopropyl triethoxysiloxane to the vanillyl epoxy compound, heat to 130°C and react for 1 hour, add KOH, stir manually, and when the solution becomes viscous or bubbles emerge, the reaction is over, and quickly pour the reaction mixture into a polytetrafluoroethylene (PTFE) mold for curing.

[0047] Step 4: The reaction mixture is pre-cured at 50°C for 2 hours, cured at 80°C for 3 hours, and post-cured at 120°C for 1 hour, to finally obtain a bio-based epoxy glass polymer film.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a bio-based epoxy glass polymer material modified by siloxane, characterized in that: include: S1, dissolving a diamine compound and vanillin in methanol, heating in a water bath under a nitrogen atmosphere for reaction, and post-treating the obtained product to obtain a vanillyl diphenol compound; S2, dissolving the vanillyl diphenol compound and the epoxy compound in N,N-dimethylformamide, and heating the mixture in an oil bath under a nitrogen atmosphere to obtain a preliminary prepolymer; S3, adding 3-aminopropyl triethoxysiloxane to the preliminary prepolymer for reaction, then adding KOH for reaction, curing the reaction mixture by gradient temperature increase to prepare a bio-based epoxy glass polymer material.

2. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The molar ratio of diamine compounds to vanillin in S1 is 1:2, and the total added amount of diamine compounds and vanillin in S1 accounts for 20 wt%-60 wt% of methanol.

3. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The molar ratio of the active H of the vanillyl diphenol compound to the epoxy group of the epoxy compound in S2 is 1:

1.

4. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The molar ratio of active H groups in the vanillyl epoxy compound and 3-aminopropyltriethoxysiloxane in the prepolymer of S3 is 1:

1.

5. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The reaction temperature in S1 is 70°C and the reaction time is 6h; the reaction temperature in S2 is 90-120°C and the reaction time is 3-5h; the reaction temperature in S3 is 120-130°C and the reaction time is 1-2h.

6. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The diamine compound includes one of hexamethylenediamine, p-phenylenediamine and 4,4'-diaminodiphenylmethane.

7. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The epoxy compound is one of glycerol triglycidyl ether and epichlorohydrin.

8. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The curing temperature and time of the bio-based epoxy glass polymer material obtained in S3 are pre-curing at 60°C for 2h, curing at 80°C for 3h, and post-curing at 120°C for 1h.

9. The method for preparing a bio-based epoxy glass polymer material modified by siloxane according to claim 1, characterized in that: The post-treatment process in S1 is to filter and wash the obtained reaction product.

10. A bio-based epoxy glass polymer material modified by siloxane, prepared by the method for preparing a bio-based epoxy glass polymer material modified by siloxane according to any one of claims 1 to 9.

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