Acrylamido triazine as well as preparation method and application thereof

Abstract

The invention relates to the technical field of organic synthesis, in particular to acrylamido triazine and a preparation method and application thereof.The preparation method comprises the steps that 126 g of melamine is weighed and placed in a three-opening round-bottom flask, 600 g of water and 2-10 g of polymerization inhibitor are added and stirred to be uniform, 60-260 g of acrylic acid is dropwise added, the mixture is heated to 100-140 DEG C, the reaction time is 6-10 h, and a reaction solution is obtained; and filtering the reaction liquid while the reaction liquid is hot, washing a filter cake with water, acetone and ethanol respectively, and drying to obtain the acrylamido triazine. The prepared 1-acrylamide triazine can be used for free radical polymerization reaction to prepare linear formaldehyde-free polymer resin with a triazine ring as a unit structure; the prepared 1, 3-diacrylamido triazine and 1, 3, 5-triacrylamido triazine can perform or participate in free radical polymerization reaction between other unsaturated double bonds to prepare a polymer with a cross-linked structure, and a technical route for preparing an aldehyde-free high-molecular polymer based on melamine is broken through in an application technical method.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and in particular to an acrylamidotriazine and a preparation method and application thereof. Background Art

[0002] Melamine is a triazine heterocyclic compound with a high nitrogen content (66.7%). Its molecular skeleton is analogous to a benzene ring structure, and it contains reactive amino groups outside the ring, which can participate in the delocalized overlap and conjugation of the triazine ring's π electron orbitals. It exhibits significant basicity and nucleophilicity, and is capable of participating in reactions such as alkylation, acylation, oxidation, substitution, and diazotization. Melamine combines typical molecular rigidity with excellent intrinsic flame retardancy, making it an important organic chemical raw material. It is non-toxic, heat-resistant, flame-retardant, arc-resistant, highly insulating, and easily colorable.

[0003] Currently, melamine is primarily used to synthesize melamine-formaldehyde resins (melamine resins), which are directly applied in fields such as wood adhesives, molding compounds, and industrial additives. Its application technology is very narrow, with significant limitations and no other better options. Furthermore, the large amount of formaldehyde used in the preparation of melamine resins has led to the widely criticized problem of formaldehyde residue in practical applications. Furthermore, due to the significant fragmentation of melamine resins themselves, they suffer from slow aging and decomposition under wet and hot conditions, as well as slow formaldehyde release. These issues pose significant technical obstacles to the wider application of melamine.

[0004] Market realities suggest that my country possesses significant melamine production capacity, but its downstream application technology and innovation capabilities lag significantly behind. This significant disconnect between application technology and technological innovation is severely hampering the healthy, sustainable, and high-quality development of the melamine industry. High-intensity technological innovation is urgently needed to develop novel, advanced derivative structural compounds and new functional materials to promote efficient, interconnected, high-quality, healthy, and sustainable development of the melamine industry chain.

[0005] In the prior art, when using melamine and acrylic acid to undergo a dehydration reaction to prepare acrylamidotriazine (i.e., a melamine-derived monomer) that can be used in free radical polymerization reactions, the main technical points are as follows:

[0006] (1) The reaction is difficult to proceed autonomously and requires heating to promote the reaction process;

[0007] (2) Selecting an appropriate and reasonable temperature can effectively promote the dehydration reaction between melamine and acrylic acid to form a new structural compound, namely acrylamide triazine.

[0008] (3) By changing the molar ratio of melamine and acrylic acid and rationally regulating the reaction, 1-acrylamide triazine, 1,3-diacrylamide triazine, and 1,3,5-acrylamide triazine can be obtained respectively.

[0009] (4) Under appropriate heating conditions, the dehydration reaction can be effectively promoted, but it can also lead to free radical polymerization between unsaturated double bonds, thereby producing linear segments with a certain degree of polymerization. This polymerization reaction must be avoided and blocked.

[0010] To this end, the present invention provides an acrylamidotriazine and a preparation method and application thereof. Summary of the Invention

[0011] Based on this, it is necessary to provide an acrylamidotriazine and its preparation method and application to address the above technical problems. The preparation method utilizes the dehydration reaction between melamine and acrylic acid to prepare three acrylamidotriazines, which can not only promote the progress of the dehydration reaction, but also inhibit the free radical polymerization reaction between unsaturated double bonds, thereby improving the feasibility of the dehydration reaction.

[0012] According to a first aspect of the present invention, a method for preparing acrylamidotriazine is provided, comprising: step 1, weighing 126 g of melamine and placing it in a three-necked round-bottom flask, adding 600 g of water and 2-10 g of a polymerization inhibitor, stirring evenly, dropwise adding 60-260 g of acrylic acid, heating to 100-140° C., and reacting for 6-10 hours to obtain a reaction liquid; step 2, filtering the reaction liquid while hot, washing the filter cake with water, acetone, and ethanol, respectively, and drying the mixture to obtain acrylamidotriazine.

[0013] In some optional implementations of some embodiments, the polymerization inhibitor is one or more conventional polymerization inhibitors such as 2-tert-butyl-6-methylphenol, 2,6-di-tert-butyl-p-cresol, p-diphenol, m-diphenol, 2-tert-butyl-p-cresol, and phenothiazine.

[0014] In some optional implementations of some embodiments, the polymerization inhibitor is preferably 2,6-di-tert-butyl-p-cresol, and the added amount of the polymerization inhibitor is preferably 4.5 g.

[0015] In some optional implementations of some embodiments, the acrylamidotriazine includes 1-acrylamidotriazine, 1,3-diacrylamidotriazine and 1,3,5-triacrylamidotriazine.

[0016] In some optional implementations of some embodiments, the amount of acrylic acid used is 60 to 260 g, wherein the amount of acrylic acid added to prepare 1-acrylamide triazine is preferably 86 g, the amount of acrylic acid added to prepare 1,3-diacrylamide triazine is preferably 144 g, and the amount of acrylic acid added to prepare 1,3,5-triacrylamide triazine is preferably 230 g.

[0017] In some optional implementations of some embodiments, the reaction time in step 1 is 8 hours.

[0018] In some optional implementations of some embodiments, the heating temperature in step 1 is 115°C.

[0019] In some optional implementations of some embodiments, the drying condition in step 2 is vacuum drying at 30-60°C, wherein the drying condition is vacuum drying at 45°C.

[0020] According to a second aspect of the present invention, an acrylamido triazine is provided. The acrylamido triazine is prepared by the above preparation method.

[0021] In some optional implementations of some embodiments, the present application fully utilizes the chemical structure characteristics and performance advantages of melamine, adopts a synthesis scheme compatible with its reactivity, and prepares three acrylamidotriazines that can be used in the synthesis of formaldehyde-free melamine resins through dehydration reactions. Among them, the prepared 1-acrylamidotriazine can be used in free radical polymerization reactions to prepare linear formaldehyde-free polymer resins characterized by triazine rings as unit structures; the prepared 1,3-diacrylamidotriazine and 1,3,5-triacrylamidotriazine can undergo or participate in other free radical polymerization reactions between unsaturated double bonds to prepare polymers with cross-linked structures.

[0022] According to a third aspect of the present invention, there is provided an application of an acrylamidotriazine for use in the synthesis of formaldehyde-free melamine resin.

[0023] In some optional implementations of certain embodiments, the acrylamidotriazine disclosed herein, through its application technology, opens up a new technical route for preparing formaldehyde-free polymers from melamine. Furthermore, the technical method for preparing formaldehyde-free polymers using melamine derivative monomers lays a solid technical foundation for promoting the development of melamine in the field of new functional polymers and expanding the breadth of the melamine industry chain.

[0024] The advantages and beneficial effects of the present invention are:

[0025] (1) The present invention uses conventional and readily available raw materials and prepares purified acrylamidotriazines (i.e., melamine-derived monomers), specifically 1-acrylamidotriazine, 1,3-diacrylamidotriazine, and 1,3,5-triacrylamidotriazine, by rationally regulating the reaction.

[0026] (2) The preparation method of acrylamide triazine provided by the present invention has the characteristics of simple process, high efficiency, low cost and easy repeatability.

[0027] (3) The 1-acrylamide triazine prepared by the present invention can be used for free radical polymerization to prepare linear formaldehyde-free polymer resins with triazine rings as unit structural characteristics; the prepared 1,3-diacrylamide triazine and 1,3,5-triacrylamide triazine can undergo or participate in free radical polymerization reactions between other unsaturated double bonds to prepare polymers with cross-linked structures. In terms of applied technical methods, this opens up a technical route for preparing formaldehyde-free high molecular polymers based on melamine. Furthermore, the technical method of preparing formaldehyde-free high polymers using melamine derivative monomers has laid a good technical foundation for promoting the technical development of melamine in the field of new functional polymers and for broadening the breadth of the melamine industry chain. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of 1-acrylamidotriazine prepared in Example 1 of the present invention.

[0029] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of 1,3-diacrylamidotriazine prepared in Example 3 of the present invention.

[0030] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of 1,3,5-triacrylamidotriazine prepared in Example 6 of the present invention.

[0031] Figure 4 This is an infrared spectrum of an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] It should be noted that the raw materials used in the preparation and implementation of the acrylamidotriazine preparation method provided by the present invention can all be obtained through general market channels.

[0034] Example 1

[0035] In this embodiment, a method for preparing 1-acrylamidotriazine is provided, which specifically comprises the following steps: (1) 126 g of melamine is weighed and placed in a three-necked round-bottom flask, 600 g of water and 2.0 g of 2-tert-butyl-6-methylphenol are added, and the mixture is stirred evenly. 60 g of acrylic acid is added dropwise, and the mixture is heated to 100° C. for 8 hours. (2) The reaction solution is filtered while hot, and the filter cake is washed with water, acetone, and ethanol, respectively. After vacuum drying at 40° C., 1-acrylamidotriazine is obtained.

[0036] Example 2 to Example 8

[0037] For Examples 2 to 8, their specific material ratios and reaction control parameters are detailed in Table 1. Meanwhile, the preparation methods of Examples 2 to 8 are similar to that of Example 1 and can be implemented with reference to the preparation method of Example 1.

[0038] Table 1 Reaction material ratios and reaction conditions of Examples 1 to 8 (unit: mass fraction)

[0039]

[0040] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of 1-acrylamidotriazine prepared in Example 1, wherein: 1 HNMR(DMSO-d6,400MHZ): δ11.17(s,1H),7.34(s,1H,),7.15(d,2H),5.94(s,4H). Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of 1,3-diacrylamidotriazine prepared in Example 3, wherein: 1 HNMR(DMSO-d6,400MHZ): δ11.17(s,2H),7.15(s,3H),7.15(d,3H),5.95(s,2H). Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of 1,3,5-triacrylamidotriazine prepared in Example 6, wherein: 1 HNMR(DMSO-d6,400MHZ): δ11.20(s,3H),7.18(d,9H). Figure 4 The infrared spectra are for infrared structural testing of melamine (#0), 1-acrylamidotriazine (#1), 1,3-diacrylamidotriazine (#2), 1,3,5-triacrylamidotriazine (#3), and acrylic acid (AA), wherein melamine and acrylic acid are commercially available raw materials, 1-acrylamidotriazine is the 1-acrylamidotriazine prepared in Example 1, 1,3-diacrylamidotriazine is the 1,3-diacrylamidotriazine prepared in Example 3, and 1,3,5-triacrylamidotriazine is the 1,3,5-triacrylamidotriazine prepared in Example 6.

[0041] Reference Attachment Figure 4 It can be seen that in the melamine structure, 3473, 3415, 3334, 3125 cm -1 and 1648cm -1 The stretching vibration peaks at 1537 and 813 cm-1 are attributed to the primary amine (NH) outside the triazine ring. -1 The absorption peaks are attributed to the in-plane and out-of-plane stretching vibrations of the triazine ring. In contrast, in the structure of acrylamide triazine (1-acrylamido triazine, 1,3-diacrylamide triazine and 1,3,5-triacrylamido triazine), the absorption peaks at 3285 cm -1 There are obvious characteristic absorption peaks of amide groups at 3020 and 2850 cm -1 It is attributed to the characteristic absorption peak of the carbon-carbon double bond in the acrylamide triazine structure. In addition, the characteristic absorption peak of its amide group (-C=O) appears at 1700 cm -1 At 1720 cm, relative to AA, the characteristic absorption peak of the carboxyl group (-C=O) is -1 , a red shift phenomenon occurs.

[0042] In summary, through the analysis of relevant data, it can be seen that the acrylamide triazine structure contains both an amide group and a carbon-carbon double bond group, indicating the successful preparation of acrylamide triazine.

[0043] Obviously, those skilled in the art will appreciate that the various steps of the present invention described above can be performed in different ways than the present invention, and that simulation methods and experimental equipment include but are not limited to those described above. The various steps of the present invention described above can, in some cases, be performed in a different order than that shown here, and the steps shown or described above can be performed separately. Therefore, the present invention is not limited to any particular combination of hardware and software.

[0044] The above content is a further detailed description of the present invention in conjunction with specific embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A method for preparing acrylamidotriazine, characterized in that: include: Step 1, weighing 126g of melamine and placing it in a three-necked round-bottom flask, adding 600g of water and 2-10g of polymerization inhibitor, stirring evenly, adding 60-260g of acrylic acid dropwise, heating to 100-140°C, reacting for 6-10h, and obtaining a reaction solution; Step 2: Filter the reaction solution while hot, wash the filter cake with water, acetone, and ethanol, respectively, and dry it to obtain acrylamidotriazine.

2. The method for preparing acrylamidotriazine according to claim 1, wherein: The polymerization inhibitor is one or more of conventional polymerization inhibitors such as 2-tert-butyl-6-methylphenol, 2,6-di-tert-butyl-p-cresol, p-diphenol, m-diphenol, 2-tert-butyl-p-cresol, and phenothiazine.

3. The method for preparing acrylamidotriazine according to claim 2, wherein: The polymerization inhibitor is 2,6-di-tert-butyl-p-cresol, and the added amount of the polymerization inhibitor is 4.5 g.

4. The method for preparing acrylamidotriazine according to claim 1, wherein: The acrylamidotriazine includes 1-acrylamidotriazine, 1,3-diacrylamidotriazine and 1,3,5-triacrylamidotriazine.

5. The method for preparing acrylamidotriazine according to claim 4, wherein: If 1-acrylamidotriazine is prepared, the amount of acrylic acid added is 86 g; if 1,3-diacrylamidotriazine is prepared, the amount of acrylic acid added is 144 g; if 1,3,5-triacrylamidotriazine is prepared, the amount of acrylic acid added is 230 g.

6. The method for preparing acrylamidotriazine according to claim 1, wherein: The reaction time in step 1 is 8 h.

7. The method for preparing acrylamidotriazine according to claim 1, wherein: The heating temperature in step 1 is 115°C.

8. The method for preparing acrylamidotriazine according to claim 1, wherein: The drying condition in step 2 is vacuum drying at 30-60°C.

9. An acrylamidotriazine, characterized in that The acrylamidotriazine is obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the acrylamidotriazine according to claim 9 in the synthesis of formaldehyde-free melamine resin.

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