Low-temperature curing type rosin modified phenolic resin and preparation method thereof

Abstract

The invention belongs to the technical field of phenolic resin synthesis, and particularly relates to low-temperature curing type rosin modified phenolic resin and a preparation method thereof.The low-temperature curing type rosin modified phenolic resin is prepared from, by weight, 100 parts of phenol, 150-220 parts of formaldehyde aqueous solution, 20-40 parts of rosin, 5-10 parts of diphenyl cyclooctyne-sulfydryl and 7-12 parts of diphenyl azide phosphate; the preparation method comprises the following steps: modifying traditional phenolic resin by using rosin, diphenyl cyclooctyne-sulfydryl and diphenyl azide phosphate; rosin molecules contain a plurality of carbon chains and flexible annular structures, the resin system is introduced, the acting force between the molecular chains can be weakened, carbon-carbon double bonds of the rosin molecules can be subjected to an alkene click reaction with sulfydryl of diphenyl cyclooctyne-sulfydryl, and the flexibility is improved; in order to realize low-temperature curing, diphenyl cyclooctyne-sulfydryl is introduced into synthesis of the phenolic resin, a basis is provided for click chemical reaction, and then the phenolic resin reacts with azide groups in diphenyl azide phosphate, so that a low-temperature curing effect is finally achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of phenolic resin synthesis, and specifically relates to a low-temperature curing rosin-modified phenolic resin and a preparation method thereof. Background Art

[0002] As an important thermosetting resin, phenolic resin is widely used in many industries such as electronics, machinery, coatings, adhesives, etc. due to its excellent heat resistance, good mechanical properties and excellent electrical insulation.

[0003] Traditional phenolic resins have some limitations. On the one hand, the modification process is ineffective, brittle, or physical modification with external materials makes it difficult to achieve substantial changes in the molecule. On the other hand, the curing process of phenolic resins mostly needs to be carried out under high temperature conditions, which not only consumes a lot of energy, but also limits its use in some temperature-sensitive fields.

[0004] Therefore, the modification of phenolic resin is particularly important. Summary of the invention

[0005] In view of the defects of the prior art, the present invention discloses a low-temperature curing rosin-modified phenolic resin and a preparation method thereof. The scheme selects rosin, diphenylcyclooctyne-thiol and diphenyl phospho-azido to modify the traditional phenolic resin. First, the molecular structure of rosin contains multiple carbon chains and some flexible ring structures. After the rosin is introduced into the phenolic resin system, the interaction force between the molecular chains is weakened and the activity of the molecular chains is increased. At the same time, the rich carbon-carbon double bonds in the rosin can react with the thiol in the diphenylcyclooctyne-thiol to produce an ene click reaction, so that the overall flexibility of the resin is significantly improved. In order to further cure the room temperature phenolic resin at low temperature, the diphenylcyclooctyne-thiol is introduced into the synthesis process of the phenolic resin by designing a click chemical reaction. The diphenylcyclooctyne-thiol is rich in a large number of alkyne groups and provides a reaction basis for the occurrence of the click reaction. Furthermore, an azide group is introduced into diphenyl chlorophosphate to react with the alkyne group in the diphenylcyclooctyne-thiol to produce a click chemical reaction, so as to achieve the effect of low-temperature curing.

[0006] To achieve the above object, the technical solution adopted by the present invention is a low-temperature curing rosin-modified phenolic resin, comprising the following raw materials in parts by weight: 100 parts of phenol, 150-220 parts of formaldehyde aqueous solution, 20-40 parts of rosin, 5-10 parts of diphenylcyclooctyne-mercapto and 7-12 parts of diphenylphosphoazide;

[0007] Furthermore, the preparation method of diphenylphosphoryl azide comprises the following steps:

[0008] (a) weighing diphenyl chlorophosphate and adding it to tetrahydrofuran, stirring for 30 minutes at a stirring power of 0.5 kW, wherein the ratio of diphenyl chlorophosphate to tetrahydrofuran is 5-10 ml:50 ml, to obtain solution a; weighing sodium azide and adding it to tetrahydrofuran, stirring for 1 hour at a stirring power of 0.2 kW, wherein the ratio of sodium azide to tetrahydrofuran is 8-15 g:50 ml, to obtain solution b;

[0009] (b) adding tetrabutylammonium bromide to the solution a obtained in step (a), stirring for 40 minutes at a stirring power of 0.3 kW, wherein the mass ratio of tetrabutylammonium bromide to diphenyl chlorophosphate is 1.5-3%, to obtain a solution c, slowly adding the solution b obtained in step (a) to the solution c, stirring at a stirring power of 0.5 kW and heating at 45-60° C. for 2 hours, naturally cooling to room temperature, filtering, and obtaining a diphenyl phosphate azide precursor;

[0010] (c) The diphenylphosphoryl azide precursor obtained in step (b) is subjected to reduced pressure distillation at a pressure of 5 kPa, a temperature of 25° C., and a reduced pressure time of 2 h to obtain diphenylphosphoryl azide.

[0011] Furthermore, the preparation method of the diphenylcyclooctyne-thiol comprises the following steps:

[0012] (α) Weighing diphenylcyclooctyne-amino group, adding it to chloroform, stirring for 30 minutes at a stirring power of 0.5 kW, wherein the ratio of diphenylcyclooctyne-amino group to chloroform is 3-6 g:25 ml, to obtain reaction solution I; weighing thioglycolic acid, adding it to chloroform, stirring, stirring for 30 minutes at a stirring power of 0.5 kW, wherein the ratio of thioglycolic acid to chloroform is 5-8 ml:25 ml, to obtain reaction solution II;

[0013] (β) adding the reaction solution II obtained in step (a) to the reaction solution I, adding a triethylamine solution, wherein the amount of the triethylamine solution is 5-15% of the chloroform in the reaction solution I, heating at 80° C. for 2 h using a condenser reflux tube device, stirring at a stirring power of 0.5 kW, and naturally cooling to room temperature to obtain an organic phase;

[0014] (γ) washing the organic phase obtained in step (β) with water until it is neutral and separated to obtain a diphenylcyclooctyne-thiol precursor;

[0015] (δ) The diphenylcyclooctyne-mercapto precursor obtained in step (γ) is subjected to reduced pressure distillation at a pressure of 5 kPa, a temperature of 25° C., and a reduced pressure time of 2 h to obtain diphenylcyclooctyne-mercapto.

[0016] The present invention also provides a method for preparing a low-temperature curing rosin-modified phenolic resin, comprising the following steps:

[0017] Step 1, weigh 100 parts of phenol and dissolve them in 150-220 parts of formaldehyde aqueous solution, the concentration of the formaldehyde aqueous solution is 45%, stir for 30 minutes under the condition of stirring power of 0.5kw, add sodium hydroxide alkali solution to control pH 7.5-8.5, the concentration of sodium hydroxide is 1mol / L, heat at 70-90°C, and stir for 2.5h under the condition of stirring power of 0.5kw to obtain a phenolic intermediate;

[0018] Step 2: Weigh 20-40 parts of rosin and add it to the phenolic intermediate obtained in step 1, raise the temperature to 110-120° C., and stir for 40 minutes at a stirring power of 0.5 kW to obtain a phenolic modified product;

[0019] Step 3, weigh 5-10 parts of diphenylcyclooctyne-mercapto and add them to the phenolic modified product obtained in step 2, cool them by 60-80° C., and stir them for 1.5 hours at a stirring power of 0.5 kW to obtain a functionalized phenolic resin;

[0020] Step 4: weigh 7-12 parts of diphenyl phosphate azide and copper bromide and add them to the functionalized phenolic resin obtained in step 3, wherein the amount of copper bromide accounts for 2-4% of diphenyl phosphate azide, keep warm at 60-80°C, and stir for 2 hours at a stirring power of 0.5kw, add dilute hydrochloric acid solution to control it to neutral, the concentration of dilute hydrochloric acid is 0.5mol / L, filter and maintain 60-80°C at a pressure of 10kpa for curing treatment for 3 hours to obtain a low-temperature curing rosin-modified phenolic resin.

[0021] The beneficial effects achieved by the present invention are as follows:

[0022] The low-temperature curing rosin-modified phenolic resin prepared by the present invention introduces diphenylcyclooctyne-thiol groups during the synthesis process of the phenolic resin, which is rich in a large number of alkyne groups. The alkyne groups have high chemical reactivity and provide a good reaction basis for the occurrence of a click reaction. Furthermore, an azide group is further introduced into diphenyl chlorophosphate so that a click chemical reaction occurs between the azide group and the alkyne group in the diphenylcyclooctyne-thiol group. During the click chemical reaction, the azide group and the alkyne group can react quickly and efficiently under relatively mild conditions to form a stable triazole ring structure, thereby realizing cross-linking between molecules and achieving a low-temperature curing effect, thereby broadening the application range of the phenolic resin and enabling the phenolic resin to be effectively used in some environments with relatively strict temperature requirements.

[0023] The low-temperature curing rosin-modified phenolic resin prepared by the present invention contains multiple carbon chains and some flexible cyclic structures in its molecular structure, such as abietic acid-type resin acid, pimaric acid-type resin acid, etc. These structures give the rosin unique physical and chemical properties. When the rosin is introduced into the phenolic resin system, it can play a role similar to that of a "plasticizer" between the molecular chains of the resin. This is because the flexible cyclic structure and carbon chain of the rosin can be inserted between the molecular chains of the phenolic resin, thereby weakening the interaction force between the molecular chains, increasing the activity of the molecular chains, and significantly improving the overall flexibility of the resin, which greatly improves the disadvantage of the phenolic resin being relatively brittle. In addition, the rosin is rich in carbon-carbon double bonds, and can undergo an ene-click reaction with the thiol group in the diphenylcyclooctyne-thiol group, further introducing a relatively flexible segment into the molecular chain of the phenolic resin, thereby effectively reducing the brittleness of the resin and improving its flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A diagram of a method for preparing a low-temperature curing rosin-modified phenolic resin proposed by the present invention;

[0025] Figure 2 The structural diagram of the diphenylcyclooctyne-thiol group proposed by the present invention;

[0026] Figure 3 The synthetic process diagram of the diphenylcyclooctyne-thiol proposed by the present invention;

[0027] Figure 4 The structural diagram of diphenyl phosphoryl azide proposed by the present invention;

[0028] Figure 5 The synthetic process diagram of diphenylphosphoryl azide proposed by the present invention;

[0029] Figure 6 The bending strength test and impact strength test diagram of the low-temperature curing rosin-modified phenolic resin prepared in the examples and comparative examples of the present invention are shown;

[0030] Figure 7 The figure is a temperature variation resistance test diagram of the low-temperature curing rosin-modified phenolic resin prepared in the examples and comparative examples of the present invention;

[0031] Figure 8 The graph is a weight loss graph of the low-temperature curing rosin-modified phenolic resin prepared in the examples of the present invention and the comparative examples.

[0032] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0035] The preparation methods in the following examples are referred to Figure 1 , the structure of diphenylphosphoryl azide is referenced Figure 4 The synthesis process of diphenylphosphoryl azide is as follows Figure 5 , the structure of diphenylcyclooctyne-thiol is referenced Figure 2 The synthesis process of diphenylcyclooctyne-thiol is as follows Figure 3 Unless otherwise specified, all methods are conventional; the materials used in the following embodiments, unless otherwise specified, are new materials purchased from the market.

[0036] Example 1: This example provides a low-temperature curing rosin-modified phenolic resin, comprising the following raw materials in parts by weight: 100 parts of phenol, 150 parts of formaldehyde aqueous solution, 20 parts of rosin, 5 parts of diphenylcyclooctyne-mercapto and 7 parts of diphenylphosphoryl azide;

[0037] The preparation method of diphenylphosphoryl azide comprises the following steps:

[0038] (a) 5 ml of diphenyl chlorophosphate was added to 50 ml of tetrahydrofuran, and stirred for 30 min at a stirring power of 0.5 kW to obtain solution a; 8 g of sodium azide was added to 50 ml of tetrahydrofuran, and stirred for 1 h at a stirring power of 0.2 kW to obtain solution b;

[0039] (b) adding tetrabutylammonium bromide to the solution a obtained in step (a) and stirring for 40 minutes at a stirring power of 0.3 kW, wherein the mass ratio of tetrabutylammonium bromide to diphenyl chlorophosphate is 1.5%, to obtain a solution c, slowly adding the solution b obtained in step (a) and stirring at a stirring power of 0.5 kW and heating at 45° C. for 2 hours, naturally cooling to room temperature, and filtering to obtain a diphenyl phosphate azide precursor;

[0040] (c) The diphenylphosphoryl azide precursor obtained in step (b) is subjected to reduced pressure distillation at a pressure of 5 kPa for 2 h and a temperature of 25° C. to obtain diphenylphosphoryl azide.

[0041] The preparation method of diphenylcyclooctyne-sulfhydryl comprises the following steps:

[0042] (α) Weigh 3 g of diphenylcyclooctyne-amino and add it to 25 ml of chloroform, stir for 30 min at a stirring power of 0.5 kW to obtain reaction solution I; weigh 5 ml of thioglycolic acid and add it to 25 ml of chloroform and stir for 30 min at a stirring power of 0.5 kW to obtain reaction solution II;

[0043] (β) adding the reaction solution II obtained in step (a) to the reaction solution I, adding 1.25 ml of triethylamine solution, wherein the amount of triethylamine solution is 5% of the chloroform in the reaction solution I, heating at 80° C. for 2 h using a condenser reflux tube device, stirring at a stirring power of 0.5 kW, and naturally cooling to room temperature to obtain an organic phase;

[0044] (γ) washing the organic phase obtained in step (β) with water until it is neutral and extracting and separating to obtain a diphenylcyclooctyne-thiol precursor;

[0045] (δ) The diphenylcyclooctyne-mercapto precursor obtained in step (γ) is subjected to reduced pressure distillation at a pressure of 5 kPa for 2 h and a temperature of 25° C. to obtain diphenylcyclooctyne-mercapto.

[0046] This embodiment also provides a method for preparing a low-temperature curing rosin-modified phenolic resin, comprising the following steps:

[0047] Step 1, weigh 100 parts of phenol and dissolve it in 150 parts of 45% formaldehyde aqueous solution, stir for 30 minutes under the condition of stirring power of 0.5kw, add 1mol / L sodium hydroxide alkali solution to control pH 7.5, heat to 70-90°C, and stir for 2.5 hours under the condition of stirring power of 0.5kw to obtain a phenolic intermediate;

[0048] Step 2: Weigh 20 parts of rosin and add it to the phenolic intermediate obtained in step 1, heat it to 110° C., and stir it for 40 minutes at a stirring power of 0.5 kW to obtain a phenolic modified product;

[0049] Step 3: weigh 5 parts of diphenylcyclooctyne-mercapto and add them to the phenolic modified product obtained in step 2, lower the temperature to 60° C., and stir for 1.5 hours at a stirring power of 0.5 kW to obtain a functionalized phenolic resin;

[0050] Step 4: weigh 7 parts of diphenyl phosphohydride and 0.14 parts of copper bromide and add them to the functionalized phenolic resin obtained in step 3, keep warm at 60°C, and stir for 2 hours at a stirring power of 0.5 kw, add 0.5 mol / L dilute hydrochloric acid solution to control it to neutral, filter and maintain 60°C at a pressure of 10 kPa for curing treatment for 3 hours to obtain a low-temperature curing rosin-modified phenolic resin.

[0051] Example 2: This example provides a low-temperature curing rosin-modified phenolic resin, comprising the following raw materials in parts by weight: 100 parts of phenol, 180 parts of formaldehyde aqueous solution, 30 parts of rosin, 8 parts of diphenylcyclooctyne-mercapto and 10 parts of diphenylphosphoazide;

[0052] The preparation method of diphenylphosphoryl azide comprises the following steps:

[0053] (a) 8 ml of diphenyl chlorophosphate was added to 50 ml of tetrahydrofuran, and stirred for 30 min at a stirring power of 0.5 kW to obtain solution a; 12 g of sodium azide was added to 50 ml of tetrahydrofuran, and stirred for 1 h at a stirring power of 0.2 kW to obtain solution b;

[0054] (b) adding tetrabutylammonium bromide to the solution a obtained in step (a) and stirring for 40 minutes at a stirring power of 0.3 kW, wherein the mass ratio of tetrabutylammonium bromide to diphenyl chlorophosphate is 2.3%, to obtain a solution c, slowly adding the solution b obtained in step (a) and stirring at a stirring power of 0.5 kW and heating at 53° C. for 2 hours, naturally cooling to room temperature, and filtering to obtain a diphenyl phosphate azide precursor;

[0055] (c) The diphenylphosphoryl azide precursor obtained in step (b) is subjected to reduced pressure distillation at a pressure of 5 kPa for 2 h and a temperature of 25° C. to obtain diphenylphosphoryl azide.

[0056] The preparation method of diphenylcyclooctyne-sulfhydryl comprises the following steps:

[0057] (α) Weigh 4.5 g of diphenylcyclooctyne-amino group and add it to 25 ml of chloroform, stir for 30 min at a stirring power of 0.5 kW to obtain reaction solution I; weigh 6.5 ml of thioglycolic acid and add it to 25 ml of chloroform, stir for 30 min at a stirring power of 0.5 kW to obtain reaction solution II;

[0058] (β) adding the reaction solution II obtained in step (a) to the reaction solution I, adding 2.5 ml of triethylamine solution, wherein the amount of triethylamine solution is 10% of the chloroform in the reaction solution I, heating at 80° C. for 2 h using a condenser reflux tube device, stirring at a stirring power of 0.5 kW, and naturally cooling to room temperature to obtain an organic phase;

[0059] (γ) washing the organic phase obtained in step (β) with water until it is neutral and extracting and separating to obtain a diphenylcyclooctyne-thiol precursor;

[0060] (δ) The diphenylcyclooctyne-mercapto precursor obtained in step (γ) is subjected to reduced pressure distillation at a pressure of 5 kPa for 2 h and a temperature of 25° C. to obtain diphenylcyclooctyne-mercapto.

[0061] This embodiment also provides a method for preparing a low-temperature curing rosin-modified phenolic resin, comprising the following steps:

[0062] Step 1, weigh 100 parts of phenol and dissolve it in 190 parts of 45% formaldehyde aqueous solution, stir for 30 minutes under the condition of stirring power of 0.5kw, add 1mol / L sodium hydroxide alkali solution to control pH 8, heat to 80°C, and stir for 2.5h under the condition of stirring power of 0.5kw to obtain a phenolic intermediate;

[0063] Step 2: Weigh 30 parts of rosin and add it to the phenolic intermediate obtained in step 1, heat it to 115° C., and stir it for 40 minutes at a stirring power of 0.5 kW to obtain a phenolic modified product;

[0064] Step 3, weigh 8 parts of diphenylcyclooctyne-mercapto and add them to the phenolic modified product obtained in step 2, lower the temperature to 70° C., and stir for 1.5 hours at a stirring power of 0.5 kW to obtain a functionalized phenolic resin;

[0065] Step 4: Weigh 10 parts of diphenyl phosphoazide and 0.3 parts of copper bromide and add them to the functionalized phenolic resin obtained in step 3, keep warm at 70°C, and stir for 2 hours at a stirring power of 0.5 kw, add 0.5 mol / L dilute hydrochloric acid solution to control it to neutral, filter and maintain 70°C at a pressure of 10 kPa for curing treatment for 3 hours to obtain a low-temperature curing rosin-modified phenolic resin.

[0066] Example 3: This example provides a low-temperature curing rosin-modified phenolic resin, comprising the following raw materials in parts by weight: 100 parts of phenol, 220 parts of formaldehyde aqueous solution, 40 parts of rosin, 10 parts of diphenylcyclooctyne-mercapto and 12 parts of diphenylphosphoazide;

[0067] The preparation method of diphenylphosphoryl azide comprises the following steps:

[0068] (a) 10 ml of diphenyl chlorophosphate was added to 50 ml of tetrahydrofuran, and stirred for 30 min at a stirring power of 0.5 kW to obtain solution a; 15 g of sodium azide was added to 50 ml of tetrahydrofuran, and stirred for 1 h at a stirring power of 0.2 kW to obtain solution b;

[0069] (b) adding tetrabutylammonium bromide to the solution a obtained in step (a) and stirring for 40 minutes at a stirring power of 0.3 kW, wherein the mass ratio of tetrabutylammonium bromide to diphenyl chlorophosphate is 3%, to obtain a solution c, slowly adding the solution b obtained in step (a) and stirring at a stirring power of 0.5 kW and heating at 60° C. for 2 hours, naturally cooling to room temperature, and filtering to obtain a diphenyl phosphate azide precursor;

[0070] (c) The diphenylphosphoryl azide precursor obtained in step (b) is subjected to reduced pressure distillation at a pressure of 5 kPa for 2 h and a temperature of 25° C. to obtain diphenylphosphoryl azide.

[0071] The preparation method of diphenylcyclooctyne-sulfhydryl comprises the following steps:

[0072] (α) Weigh 6 g of diphenylcyclooctyne-amino and add it to 25 ml of chloroform, stir for 30 min at a stirring power of 0.5 kW to obtain reaction solution I; weigh 8 ml of thioglycolic acid and add it to 25 ml of chloroform and stir for 30 min at a stirring power of 0.5 kW to obtain reaction solution II;

[0073] (β) adding the reaction solution II obtained in step (a) to the reaction solution I, adding 3.75 ml of triethylamine solution, wherein the amount of triethylamine solution is 15% of the chloroform in the reaction solution I, heating at 80° C. for 2 h using a condenser reflux tube device, stirring at a stirring power of 0.5 kW, and naturally cooling to room temperature to obtain an organic phase;

[0074] (γ) washing the organic phase obtained in step (β) with water until it is neutral and extracting and separating to obtain a diphenylcyclooctyne-thiol precursor;

[0075] (δ) The diphenylcyclooctyne-mercapto precursor obtained in step (γ) is subjected to reduced pressure distillation at a pressure of 5 kPa for 2 h and a temperature of 25° C. to obtain diphenylcyclooctyne-mercapto.

[0076] This embodiment also provides a method for preparing a low-temperature curing rosin-modified phenolic resin, comprising the following steps:

[0077] Step 1, weigh 100 parts of phenol and dissolve it in 220 parts of 45% formaldehyde aqueous solution, stir for 30 minutes under the condition of stirring power of 0.5kw, add 1mol / L sodium hydroxide alkali solution to control pH 8.5, heat to 90°C, and stir for 2.5 hours under the condition of stirring power of 0.5kw to obtain a phenolic intermediate;

[0078] Step 2: Weigh 40 parts of rosin and add it to the phenolic intermediate obtained in step 1, heat it to 120° C., and stir it for 40 minutes at a stirring power of 0.5 kW to obtain a phenolic modified product;

[0079] Step 3: weigh 10 parts of diphenylcyclooctyne-mercapto and add them to the phenolic modified product obtained in step 2, lower the temperature to 80° C., and stir for 1.5 hours at a stirring power of 0.5 kW to obtain a functionalized phenolic resin;

[0080] Step 4: weigh 12 parts of diphenyl phosphoazide and 0.48 parts of copper bromide and add them to the functionalized phenolic resin obtained in step 3, keep warm at 80°C, and stir for 2 hours at a stirring power of 0.5 kw, add 0.5 mol / L dilute hydrochloric acid solution to control it to neutral, filter and maintain 80°C at a pressure of 10 kPa for curing treatment for 3 hours to obtain a low-temperature curing rosin-modified phenolic resin.

[0081] Comparative Example:

[0082] The difference between Comparative Example 1 and Example 2 is that no rosin is added, and the rest is the same as Example 2;

[0083] The difference between Comparative Example 2 and Example 2 is that diphenylcyclooctyne-amino and mercaptoacetic acid are not added, and the rest is the same as Example 2;

[0084] Comparative Example 3 is ordinary phenolic resin.

[0085] The properties of the prepared low-temperature curing rosin-modified phenolic resin were tested in terms of flexural strength, impact strength, temperature change resistance and weight loss rate. Figure 6 As the results of bending strength and impact strength, it can be seen that the low-temperature curing rosin-modified phenolic resin prepared in Example 2 exhibits good bending strength. The bending strength of Example 2 reaches 70.4 MPa, and the impact strength reaches 5.5 KJ / ㎡, showing good toughness; and the deformation temperature test of the prepared low-temperature curing rosin-modified phenolic resin is as follows Figure 7 As shown, the temperature change resistance of Example 2 reaches 198°C, which is much higher than that of the comparative example, indicating good stability; and the weight loss rate of the low-temperature curing rosin-modified phenolic resin is further tested as follows Figure 8 As shown, it can be seen that the weight loss rate of the embodiment is much lower than that of the comparative example, indicating that the low-temperature curing rosin-modified phenolic resin exhibits higher purity.

[0086] From the above analysis, it can be seen that the obtained low-temperature curing rosin-modified phenolic resin exhibits better performance.

[0087] Obviously, the above comparative examples and embodiments are only a part of comparative examples and embodiments of the present invention, and they and the comparative examples and embodiments based on such references are all within the scope of protection of the present invention.

[0088] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0089] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A low temperature curing rosin modified phenolic resin, characterized in that: The method comprises the following raw materials in parts by weight: 100 parts of phenol, 150-220 parts of formaldehyde aqueous solution, 20-40 parts of rosin, 5-10 parts of diphenylcyclooctyne-mercapto and 7-12 parts of diphenylphosphoryl azide; The raw materials for preparing the diphenylcyclooctyne-thiol group include diphenylcyclooctyne-amino and thioglycolic acid, and the usage ratio of the diphenylcyclooctyne-amino and thioglycolic acid is 3-6g:5-8ml; The raw materials for preparing the diphenyl phosphate azide include diphenyl chlorophosphate and sodium azide, and the usage ratio of the sodium azide to the diphenyl chlorophosphate is 8-15g:5-10ml.

2. A low temperature curing rosin modified phenolic resin according to claim 1, characterized in that, The preparation method of diphenylphosphoryl azide comprises the following steps: (a) weighing diphenyl chlorophosphate and adding it to tetrahydrofuran and stirring to obtain solution a, weighing sodium azide and adding it to tetrahydrofuran and stirring to obtain solution b; (b) adding tetrabutylammonium bromide to the solution a obtained in step (a) and stirring to obtain a solution c, slowly adding the solution b obtained in step (a) to the solution c, stirring and heating, cooling and filtering to obtain a diphenylphosphoryl azide precursor; (c) subjecting the diphenylphosphoryl azide precursor obtained in step (b) to reduced pressure distillation to obtain diphenylphosphoryl azide.

3. A low temperature curing rosin modified phenolic resin according to claim 2, characterized in that, The ratio of diphenyl chlorophosphate to tetrahydrofuran in step (a) is 5-10 ml:50 ml, the ratio of sodium azide to tetrahydrofuran is 8-15 g:50 ml, the mass ratio of tetrabutylammonium bromide to diphenyl chlorophosphate in step (b) is 1.5-3%, and the heating temperature is 45-60°C.

4. A low temperature curing rosin modified phenolic resin according to claim 1, characterized in that: The preparation method of the diphenylcyclooctyne-thiol comprises the following steps: (α) Weighing diphenylcyclooctyne-amino and adding it to chloroform and stirring to obtain a reaction solution I, and weighing thioglycolic acid and adding it to chloroform and stirring to obtain a reaction solution II; (β) adding the reaction solution II obtained in step (a) to the reaction solution I, adding a triethylamine solution, heating and stirring, and cooling to obtain an organic phase; (γ) washing the organic phase obtained in step (β) with water until it is neutral and separated to obtain a diphenylcyclooctyne-thiol precursor; (δ) The diphenylcyclooctyne-mercapto precursor obtained in step (γ) is subjected to reduced pressure distillation to obtain diphenylcyclooctyne-mercapto.

5. A low temperature curing rosin modified phenolic resin according to claim 4, characterized in that: The heating process described in step (β) is heated by using a device with a condensation reflux pipe, the heating temperature is 80° C., and the heating time is 1-3 hours.

6. A method for preparing a low-temperature curing rosin-modified phenolic resin according to any one of claims 1 to 5, characterized in that: The steps include: Step 1, weigh phenol, dissolve it in a formaldehyde aqueous solution and stir, add alkali solution to control the pH, heat and stir to obtain a phenolic intermediate; Step 2: Weigh rosin and add it to the phenolic intermediate obtained in step 1, heat it and stir it to obtain a phenolic modified product; Step 3, weighing diphenylcyclooctyne-mercapto group and adding it to the phenolic modified product obtained in step 2, cooling and stirring to obtain a functionalized phenolic resin; Step 4: weigh diphenyl phosphoazide and copper bromide and add them to the functionalized phenolic resin obtained in step 3, keep warm and stir, add acid solution to control it to be neutral, filter and cure to obtain a low-temperature curing rosin-modified phenolic resin.

7. The method for preparing a low-temperature curing rosin-modified phenolic resin according to claim 6, wherein: The pH range of step 1 is 7.5-8.5.

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