CN111909117B - Phthalic anhydride diisopropanol amide epoxy resin and preparation method and application thereof - Google Patents

Abstract

The invention provides a phthalic anhydride diisopropanol amide epoxy resin and a preparation method and application thereof, belonging to the technical field of organic synthesis, wherein the main component is phthalic anhydride diisopropanol amide polyglycidyl ether, and the mass percentage content of the phthalic anhydride diisopropanol amide polyglycidyl ether in the phthalic anhydride diisopropanol amide epoxy resin is more than or equal to 70%. The phthalic anhydride diisopropanol amide epoxy resin provided by the invention has an epoxy value of 0.42-0.49 eq/100g, has low viscosity, and can enhance the rigidity, toughness and high temperature resistance of an E-51 epoxy resin condensate. The invention also provides a preparation method of the epoxy resin in the technical scheme, which ensures the epoxidation degree of the raw materials by controlling the temperature, time and proportion of the reaction, so that the final epoxy resin has higher epoxy value and lower viscosity; can improve the high temperature resistance, rigidity and toughness of the cured epoxy resin.

Description

A kind of phthalic anhydride diisopropanolamide epoxy resin and preparation method and application thereof

technical field

The invention relates to the technical field of organic synthesis, in particular to a phthalic anhydride diisopropanolamide epoxy resin and a preparation method and application thereof.

Background technique

Epoxy resin generally refers to an organic compound containing two or more epoxy groups in the molecule, and its molecular structure is characterized by the presence of active epoxy groups in the molecular chain. Oxygen groups, so that they can cross-link with various types of curing agents to form insoluble polymers with a three-way network structure. The cured epoxy resin has good physical and chemical properties, excellent bonding strength, good dielectric properties, small deformation shrinkage, good dimensional stability, high hardness, good flexibility, and is resistant to alkali and most solvents. Stable, widely used in national defense and various sectors of the national economy for casting, impregnation, lamination, adhesives, coatings and other purposes. However, the epoxy resins in the prior art have problems of low epoxy value and high viscosity.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a kind of phthalic anhydride diisopropanolamide epoxy resin and its preparation method and application. The phthalic anhydride diisopropanolamide epoxy resin provided by the invention has high epoxy value and low viscosity, and can enhance the toughness, rigidity and high temperature resistance of the epoxy resin.

The invention provides a kind of phthalic anhydride diisopropanolamide epoxy resin, including phthalic anhydride diisopropanolamide polyglycidyl ether, and the structure of the phthalic anhydride diisopropanolamide polyglycidyl ether is shown in formula I:

The mass percentage content of phthalic anhydride diisopropanolamide polyglycidyl ether in the phthalic anhydride diisopropanolamide epoxy resin is ≥70%.

Preferably, the phthalic anhydride diisopropanolamide epoxy resin also includes:

Preferably, the epoxy value of the phthalic anhydride diisopropanolamide epoxy resin is 0.42-0.49eq/100g.

The present invention also provides the preparation method of the phthalic anhydride diisopropanolamide epoxy resin described in the above technical scheme, comprising the following steps:

After mixing phthalic anhydride, diisopropanolamine, dehydrating agent and organic solvent, carry out amidation reaction, simultaneously remove by-product water, after amidation reaction finishes, remove organic solvent and dehydrating agent, obtain phthalic anhydride diisopropanolamide ;

The phthalic anhydride diisopropanolamide, epichlorohydrin and inorganic base are subjected to a "one-step" ring opening and closing reaction under the action of a phase transfer catalyst, and after the reaction is completed, the phthalic anhydride diisopropanolamide ring is obtained by refining Oxygen resin.

Preferably, the molar ratio of the phthalic anhydride to diisopropanolamine is 1:(2-2.3).

Preferably, the temperature of the amidation reaction is 110-160° C., and the time is 5-9 h.

Preferably, the molar ratio of the hydroxyl group, epichlorohydrin and inorganic base of the phthalic anhydride diisopropanolamide is 1:(6-20):(0.75-1.15); the quality of the phase transfer catalyst is phthalic anhydride diisopropane 0.05-0.5% of the total mass of propanolamide, epichlorohydrin and inorganic base.

Preferably, the phase transfer catalyst is benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, tricaprylin methyl ammonium chloride, dodecyl trimethyl ammonium chloride or tetradecyl trimethyl ammonium chloride.

Preferably, the temperature of the "one-step" ring-opening and closing reaction is 30-80° C., the pressure is normal pressure, and the time is 2-6 h.

The present invention also provides the phthalic anhydride diisopropanolamide epoxy resin described in the above technical solution or the phthalic anhydride diisopropanolamide epoxy resin prepared by the preparation method described in the above technical solution as a reinforcing material in the epoxy resin applications in .

The invention provides a phthalic anhydride diisopropanolamide epoxy resin, the main component is phthalic anhydride diisopropanolamide polyglycidyl ether, and the phthalic anhydride diisopropanolamide epoxy resin is phthalic anhydride diisopropanolamide The mass percentage content of polyglycidyl ethers is greater than or equal to 70%. The phthalic anhydride diisopropanolamide epoxy resin provided by the invention has an epoxy value of 0.42-0.49eq/100g, and has a relatively low viscosity, which can enhance the rigidity, toughness and high temperature resistance of the epoxy resin cured product.

The present invention also provides a method for preparing the phthalic anhydride diisopropanolamide epoxy resin according to the above technical solution. The present invention ensures the glycidyl etherification of raw materials by controlling the temperature, time and pressure of the "one-step" ring-opening and closing reaction. degree, so that the final phthalic anhydride diisopropanolamide epoxy resin has higher epoxy value and lower viscosity.

Description of drawings

Fig. 1 is the infrared spectrogram of phthalic anhydride (a) and phthalic anhydride diisopropanolamide (b);

Fig. 2 is the hydrogen nuclear magnetic resonance spectrogram of phthalic anhydride diisopropanolamide;

Fig. 3 is the infrared spectrum of phthalic anhydride diisopropanolamide (a) and phthalic anhydride diisopropanolamide epoxy resin (b) prepared in Example 1;

Fig. 4 is the hydrogen NMR spectrogram of the phthalic anhydride diisopropanolamide epoxy resin obtained in Example 1;

Figure 5 is the SEM image of the impact fracture surface of the pure E-51 epoxy resin cured product (a) and the phthalic anhydride diisopropanolamide epoxy resin with a content of 10wt% of the cured product (b);

FIG. 6 is a graph showing the thermal weight loss of the cured product of pure E-51 epoxy resin and the cured product of phthalic anhydride diisopropanolamide epoxy resin with a content of 10 wt %.

Detailed ways

The invention provides a kind of phthalic anhydride diisopropanolamide epoxy resin, including phthalic anhydride diisopropanolamide polyglycidyl ether, and the structure of the phthalic anhydride diisopropanolamide polyglycidyl ether is shown in formula I:

The mass percentage content of phthalic anhydride diisopropanolamide polyglycidyl ether in the phthalic anhydride diisopropanolamide epoxy resin is ≥70%.

In the present invention, the phthalic anhydride diisopropanolamide epoxy resin preferably also includes:

In the present invention, the epoxy value of the phthalic anhydride diisopropanolamide polyglycidyl ether in the phthalic anhydride diisopropanolamide epoxy resin is 0.42-0.49eq/100g.

The phthalic anhydride diisopropanolamide type epoxy resin provided by the present invention contains phthalic anhydride diisopropanolamide polyglycidyl ether with a mass percentage content of ≥70%, so that the epoxy resin has a higher epoxy value and a lower viscosity , and can be used to enhance the toughness, rigidity and high temperature resistance of epoxy resins.

The present invention also provides the preparation method of the phthalic anhydride diisopropanolamide epoxy resin described in the above technical scheme, comprising the following steps:

After mixing phthalic anhydride, diisopropanolamine, dehydrating agent and organic solvent, carry out amidation reaction, simultaneously remove by-product water, after amidation reaction finishes, remove organic solvent and dehydrating agent, obtain phthalic anhydride diisopropanolamide ;

The phthalic anhydride diisopropanolamide, epichlorohydrin and inorganic base are subjected to a "one-step" ring opening and closing reaction under the action of a phase transfer catalyst, and after the reaction is completed, the phthalic anhydride diisopropanolamide ring is obtained by refining Oxygen resin.

In the present invention, after phthalic anhydride, diisopropanolamine, dehydrating agent and organic solvent are mixed, amidation reaction is carried out, and by-product water is removed simultaneously, and after amidation reaction is completed, organic solvent and dehydrating agent are removed to obtain diisopropyl phthalic anhydride Alcohol amides.

In the present invention, the molar ratio of the phthalic anhydride to diisopropanolamine is preferably 1:(2-2.3), more preferably 1:(2.03-2.2), and most preferably 1:(2.05-2.1). In the present invention, the dehydrating agent preferably includes toluene and/or xylene, more preferably xylene; the amount of the dehydrating agent is preferably 10-30% of the total mass of phthalic anhydride and diisopropanol, more preferably 15% -25%, more preferably 18-20%. In the present invention, the organic solvent preferably includes dimethyl sulfoxide, dimethylformamide, dimethylacetamide, diethylene glycol dimethyl ether and N,N' dimethylformamide (DMF). One or more of phthalic anhydride and diisopropanolamine, preferably N,N' dimethylformamide (DMF); the ratio of the total mass of the phthalic anhydride and diisopropanolamine to the mass of the organic solvent is preferably 1: (0.5～3 ), more preferably 1:(1.0 to 2.0), more preferably 1:(1.2 to 1.5).

In the present invention, the temperature of the amidation reaction is preferably 110-160° C., more preferably 120-150° C.; the amidation reaction time is preferably 5-9 h.

In the present invention, in the amidation reaction process, the by-product water produced in the amidation reaction process is preferably removed through a water separator.

In the present invention, the method of removing the organic solvent and the dehydrating agent is preferably distillation under reduced pressure.

In the present invention, the amidation reaction is preferably carried out in a four-necked flask, and the specific process of the amidation reaction is described in detail below in conjunction with the four-necked flask: adding phthalic anhydride, diisopropanolamine, an organic solvent and a dehydrating agent to the In a four-necked flask equipped with a mechanically sealed mechanical stirrer, a reflux condenser, a water separator and a thermometer, be warming up to the amidation reaction temperature and carry out the amidation reaction, and in the amidation reaction process, separate water through the water separator; After the amidation reaction is completed, the organic solvent and the dehydrating agent are removed by distillation under reduced pressure to obtain the phthalic anhydride diisopropanolamide.

After the phthalic anhydride diisopropanolamide is obtained, the phthalic anhydride diisopropanolamide, epichlorohydrin and inorganic base of the present invention undergo a "one-step" ring-opening and closing reaction under the action of a phase transfer catalyst, and after the reaction is completed, it is purified to obtain The phthalic anhydride diisopropanolamide epoxy resin.

In the present invention, the molar ratio of the hydroxyl group, epichlorohydrin (ECH) and inorganic base of the phthalic anhydride diisopropanolamide is preferably 1:(6-20):(0.75-1.15), more preferably 1: (7-15): (0.9-1.1); the hydroxyl value of the phthalic anhydride diisopropanolamide was measured by the phthalic anhydride method. In the present invention, the mass of the phase transfer catalyst is preferably 0.05-0.5% of the total mass of phthalic anhydride diisopropanolamide, epichlorohydrin and inorganic base, more preferably 0.1-0.2%.

In the present invention, the inorganic base is preferably NaOH or KOH. In the present invention, the phase transfer catalyst is preferably benzyltriethylammonium chloride (BTEAC), benzyltrimethylammonium chloride (BTMAC), tetrabutylammonium bromide (TBAB), tetrabutylchloride ammonium chloride (TBAC), tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride, more preferably benzyl trimethylammonium chloride Ethylammonium chloride (TEBA), tetrabutylammonium bromide (TBAB) or tetrabutylammonium chloride.

In the present invention, the pressure of the "one-step" ring opening and closing reaction is preferably normal pressure; the temperature is preferably 30-80°C, more preferably 40-60°C; the time is preferably 2-6h, more preferably 4h. In the present invention, the pressure of the "one-step method" ring-opening and closing reaction is set to normal pressure, the temperature is set to 30-80° C., and the time is set to 2-6 hours, so that the ring of the finally obtained phthalic anhydride diisopropanolamide epoxy resin can be obtained. The oxygen value is 0.42-0.49eq/100g; the detection of the epoxy value is preferably detected by the hydrochloric acid-acetone method.

In the present invention, the refining process preferably includes: filtering the obtained reaction solution, and sequentially subjecting the obtained filtrate to washing, neutralization and distillation to obtain the phthalic anhydride diisopropanolamide epoxy resin. In the present invention, the times of washing with water, the reagent for neutralization and the process of distillation are routine operations in the technical field.

In the present invention, the "one-step method" ring-opening and closing reaction is preferably carried out in a four-necked flask, and the specific process of the "one-step method" ring-opening and closing reaction is described in detail below in conjunction with the four-necked flask: phthalic anhydride diisopropanolamide , epichlorohydrin, inorganic base and phase transfer catalyst were added to a four-necked flask equipped with a mechanically sealed mechanical stirrer, a reflux condenser and a thermometer, and the temperature was raised to the "one-step" open and closed loop reaction temperature for "one-step" opening. closed-loop reaction.

The preparation method provided by the invention has wide raw material sources and simple operation, and can obtain the phthalic anhydride diisopropanolamide epoxy resin with the target epoxy value by controlling the "one-step method" ring opening and closing reaction conditions; at the same time, the prepared phthalic anhydride diisopropanolamide epoxy resin Propanolamide epoxy resins have lower viscosity.

The present invention also provides the phthalic anhydride diisopropanolamide epoxy resin described in the above technical solution or the phthalic anhydride diisopropanolamide epoxy resin prepared by the preparation method described in the above technical solution as a reinforcing material in the epoxy resin applications in .

In the present invention, the epoxy resin is preferably a bisphenol A type E-51 epoxy resin.

In the present invention, the phthalic anhydride diisopropanolamide epoxy resin is added to the bisphenol A type E-51 epoxy resin, which can significantly enhance the toughness, rigidity and high temperature resistance of the E-51 epoxy resin cured product.

The phthalic anhydride diisopropanolamide epoxy resin provided by the present invention and its preparation method and application are described in detail below in conjunction with the examples, but they cannot be understood as limiting the protection scope of the present invention.

Examples of raw materials used: phthalic anhydride (PA), tetrabutylammonium bromide, tetrabutylammonium chloride, benzyltriethylammonium chloride, sodium hydroxide, potassium hydroxide, epichlorohydrin (ECH), E -51 Bisphenol A epoxy resin and diethylenetriamine are industrial grade, provided by Anhui Xinyuan Technology Co., Ltd.; Diisopropanolamine (DiPA), industrial grade, produced by Nanjing Hongbaoli Co., Ltd.; Hydrochloric acid, acetone , xylene, N,N' dimethylformamide (DMF) and pyridine were all analytically pure, produced by Nanjing Chemical Reagent Co., Ltd.

The hydroxyl value of phthalic anhydride diisopropanolamide was determined by the phthalic anhydride method.

The epoxy value of phthalic anhydride diisopropanolamide epoxy resin was detected by hydrochloric acid-acetone method.

The FTIR test was carried out by the American Nicolet FTIR-360 Fourier Transform Infrared Spectrometer: potassium bromide coating method, and the measurement range was 400-4000 cm ^-1 .

The structure of the polymer was characterized by a Burker Fourier TrnasofmrAVANCE600 spectrometer with deuterated chloroform as the solvent.

Scanning electron microscope test: The fracture surface of the impacted sample was plated with gold, and the cell morphology was observed with the American Quanta200 environmental scanning electron microscope.

Use TGA/DSCl/1100SF thermogravimetric analyzer to test and analyze the thermal stability of the cured product. The test parameters of the thermogravimetric analyzer are set as follows: the heating range is 30 to 700 °C, the heating rate is 10 °C/min, and the carrier gas is nitrogen. , its flow rate is 40mL/min.

Viscosity test: Use Bruker DV-I rotational viscometer at room temperature of 25°C, select a suitable size rotor to test the viscosity of the sample, unit: mPa·s.

Example 1

Phthalic anhydride, diisopropanolamine, DMF and xylene were added to a 500mL four-necked flask equipped with a mechanical stirrer with a mechanical seal, a reflux condenser, a water separator and a thermometer. The moles of phthalic anhydride and diisopropanolamine were The ratio is 1:2.05, the quality of DMF is 140% of the quality of the reactants (phthalic anhydride, diisopropanolamine), and the quality of xylene is 20% of the quality of the reactants (phthalic anhydride, diisopropanolamine), and the temperature is raised to 150 ℃ amidation reaction for 7h, during the reaction, water is separated through a water separator; then, DMF and xylene are recovered by vacuum distillation to obtain phthalic anhydride diisopropanolamide, which is a brown-yellow glassy solid , the hydroxyl value is 459.6mgKOH/g, and the acid value is 1.9mgKOH/g.

Fig. 1 is the infrared spectrogram of phthalic anhydride (a) and phthalic anhydride diisopropanolamide (b). It can be seen from Figure 1: (a) 1847.44cm ^-1 and 1768.37cm ^-1 in the figure are the C=O stretching vibration infrared absorption peaks of the acid anhydride, and the COC stretching vibration absorption peaks in the acid anhydride molecule are located at 1255.41cm ^-1 and 1108.85cm ^- 1,713.52cm ^-1 is the absorption peak of the benzene ring; in the figure (b), the C=O stretching vibration infrared absorption peaks of the acid anhydrides at 1847.44cm ^-1 and ^{1768.37cm -1 no} longer exist, indicating that the phthalic anhydride has reacted completely; A strong characteristic absorption peak of C=O stretching vibration of tertiary amide appears at about 1687.38 cm ^-1 , and CN absorption peak at 1585.17 cm ^-1 indicates that amidation reaction has occurred, and the degree of amidation reaction is very high, and the absorption peak In the range of 1338.33～1039.42cm ^-1 is the stretching of CO, the broad and strong band at 3282.20cm ^-1 is the stretching vibration absorption band of multi-associate -OH, indicating that the compound has many hydroxyl groups. Fig. 2 is the hydrogen NMR spectrum of diisopropanolamide phthalic anhydride. The results are as follows: the singlet peaks near δ=1.15 and 1.28 are the hydrogens of the methyl groups on the alcoholamine chain, and the peaks near δ=3.43-4.0 are alcoholamines For the hydrogen of the methylene group on the chain, the peak near δ=4.75 is the peak at the hydroxyl position on the end of the alkanolamine, and δ=2.50 is the peak of the deuterated reagent DMSO; therefore, the analysis results of this spectrum show that the existence of the product is verified.

The prepared phthalic anhydride diisopropanolamide, epichlorohydrin, sodium hydroxide and benzyltriethylammonium chloride were added to a four-necked flask equipped with a mechanical stirrer with a mechanical seal, a reflux condenser and a thermometer , n (hydroxyl group in phthalic anhydride diisopropanolamide):n(ECH):n(NaOH)=1:8:1.1, the mass of benzyl triethylammonium chloride is the reactant (phthalic anhydride diisopropanolamide) , epichlorohydrin and sodium hydroxide) 0.3% of the mass, reacted at 40 ° C for 4 h, suction filtration after the reaction was completed, washed with water for neutralization, and then distilled to recover ECH low boilers to obtain the phthalic anhydride diisopropanolamides Epoxy resin, the measured epoxy value is 0.49eq/100g, and the viscosity is 2000mPa·s.

Fig. 3 is the infrared spectrum of phthalic anhydride diisopropanolamide (a) and phthalic anhydride diisopropanolamide epoxy resin (b); as can be seen from Fig. 3, the characteristic absorption peak of epoxy group appears near 909cm ^-1 , At the same time, the absorption peak of the hydroxyl group at 3361.3cm ^-1 weakened, which proved that the surface grafting was successful, and the main component was phthalic anhydride diisopropanolamide polyglycidyl ether.

Figure 4 is the hydrogen NMR spectrum of the obtained phthalic anhydride diisopropanolamide epoxy resin, it can be seen from Figure 4 that the singlet peaks near δ(ppm)=3.45, 3.68 and 3.82 are on the methylene group on the ethoxy chain and the hydrogen on the methylene group on the unclosed alcohol ether, the peaks near δ(ppm)=2.64, 2.82, 3.19 are the hydrogen on the methylene group and the methine group connected to the epoxy group, δ(ppm) )=7.28 is the peak of the deuterated reagent CDCl ₃ .

Based on the analysis of infrared spectrum and hydrogen NMR data, it can be known that the main component structural formula of phthalic anhydride diisopropanolamide epoxy resin is shown in formula I:

Example 2

Phthalic anhydride diisopropanolamide, epichlorohydrin, sodium hydroxide and tetrabutylammonium bromide prepared in Example 1 were added to a four-necked flask equipped with a mechanical stirrer with a mechanical seal, a reflux condenser and a thermometer In, n (phthalic anhydride diisopropanolamide hydroxyl): n (ECH): n (NaOH) = 1:10:1.15, the mass of tetrabutylammonium bromide is reactant (phthalic anhydride diisopropanolamide, epoxy 0.2% of the mass of chloropropane and sodium hydroxide), reacted at 60 ° C for 5 h, after the reaction was completed, suction filtration, washed with water for neutralization, and then distilled to remove ECH low boilers to obtain phthalic anhydride diisopropanolamide epoxy resin, The measured epoxy value was 0.42eq/100g, and the viscosity was 3500mPa·s.

Example 3

Phthalic anhydride diisopropanolamide, epichlorohydrin, sodium hydroxide and tetrabutylammonium chloride prepared in Example 1 were added to a four-necked flask equipped with a mechanical stirrer with a mechanical seal, a reflux condenser and a thermometer In, n (phthalic anhydride diisopropanolamide hydroxyl):n(ECH):n(NaOH)=1:7:0.95, the mass of tetrabutylammonium chloride is reactant (phthalic anhydride diisopropanolamide, epoxy 0.5% of the mass of chloropropane and sodium hydroxide), reacted at 50 ° C for 4 h, after the reaction was completed, suction filtered, neutralized and washed with water, and then distilled to remove ECH low boilers to obtain phthalic anhydride diisopropanolamide epoxy resin, The measured epoxy value was 0.46eq/100g, and the viscosity was 2700mPa·s.

Example 4

Phthalic anhydride diisopropanolamide, epichlorohydrin, sodium hydroxide and benzyltriethylammonium chloride prepared in Example 1 were added to a tetrahedron equipped with a mechanical stirrer with a mechanical seal, a reflux condenser and a thermometer. In the mouthed flask, n (phthalic anhydride diisopropanolamide hydroxyl group):n(ECH):n(NaOH)=1:6:1.1, the quality of benzyl triethylammonium chloride is reactant (phthalic anhydride diisopropanol) 0.4% of the total mass of amide, epichlorohydrin and sodium hydroxide), reacted at 60°C for 4 hours, after the reaction, suction filtered, neutralized by water washing, and then distilled to remove ECH low boilers to obtain phthalic anhydride diisopropanolamide Like epoxy resin, the measured epoxy value is 0.43eq/100g, and the viscosity is 3300mPa·s.

Example 5

Phthalic anhydride diisopropanolamide, epichlorohydrin, potassium hydroxide and benzyltriethylammonium chloride prepared in Example 1 were added to a tetrahedron equipped with a mechanical stirrer with a mechanical seal, a reflux condenser and a thermometer. In the mouthed flask, n (phthalic anhydride diisopropanolamide hydroxyl):n(ECH):n(KOH)=1:8:1.0, the quality of benzyl triethylammonium chloride is the reactant (phthalic anhydride diisopropanol) 0.5% of the total mass of amide, epichlorohydrin and sodium hydroxide), react at 50 ° C for 5 hours, after the reaction is completed, suction filtration, wash with water for neutralization, and then distill off ECH low boilers to obtain phthalic anhydride diisopropanolamide Like epoxy resin, the measured epoxy value is 0.45eq/100g, and the viscosity is 3100mPa·s.

Application example

The phthalic anhydride diisopropanolamide epoxy resin prepared in Example 1 was incorporated into E-51 epoxy resin, and then a theoretically required amount of diethylenetriamine curing agent was added for curing to obtain a cured product. The curing conditions included: at room temperature Curing for 12h, curing at 80℃ for 3h, and aging at room temperature for 10 days. The tensile strength, elongation at break, flexural strength and impact strength of the obtained cured product were tested by the GB/T2567-2008 method. The results are shown in Table 1. It can be seen from Table 1 that the incorporation of phthalic anhydride diisopropanolamide epoxy resin can significantly improve the tensile strength, elongation at break, flexural strength and impact strength of the cured E-51 epoxy resin. When the blending amount of phthalic anhydride diisopropanolamide epoxy resin is 10wt%, the tensile strength of the cured product is 90.94MPa, the bending strength is 139.88MPa, and the impact strength is 32.10kJ/m ² ; the tensile strength and The increase in impact strength reflects the increase in rigidity and toughness of the material, respectively. Combined with the data in Table 1, comprehensive consideration, when the dosage of phthalic anhydride diisopropanolamide epoxy resin is 10wt%, the performance of the cured product is the best.

Table 1 Performance test of phthalic anhydride diisopropanolamide epoxy resin mixed with E-51 epoxy resin cured product

When the content of phthalic anhydride diisopropanolamide epoxy resin was 10wt%, the impact fracture surface of the cured product was tested. Figure 5 shows the pure E-51 epoxy resin cured product (a) and phthalic anhydride diisopropanolamide The amount of epoxy-like epoxy resin added is 10wt% of the cured product (b) SEM image of the impact fracture surface, it can be seen from Figure 5 that the impact fracture surface of the pure E-51 epoxy resin cured product is relatively smooth; When the amount of phthalic anhydride diisopropanolamide epoxy resin was 10 wt%, the fracture surface of the resulting cured product was rougher, and there were "fibers", which proved that the cured product was mixed with phthalic anhydride diisopropanolamide epoxy resin. increased toughness.

Using Shimadzu DTG-60 thermogravimetric analyzer to test the thermogravimetric curve of the cured product of phthalic anhydride diisopropanolamide epoxy resin with a content of 10wt% and the cured product of E-51 epoxy resin, the results are shown in Figure 6 As shown in Figure 6, it can be seen that the initial decomposition temperature of the cured product with phthalic anhydride diisopropanolamide epoxy resin content of 10wt% is slightly lower than that of the pure E-51 epoxy resin cured product, but The rate of mass loss is also decreasing. When the temperature exceeds 450 °C, the carbonization rate of the cured product with a content of 10 wt% phthalic anhydride diisopropanolamide epoxy resin increases, indicating that phthalic anhydride diisopropanolamide epoxy resin The cured product with a resin content of 10wt% is more resistant to high temperature.

It can be seen from the above examples: the phthalic anhydride diisopropanolamide epoxy resin provided by the present invention has a relatively high epoxy value, and after being incorporated into the E-51 resin, the toughness, rigidity and high temperature resistance of the cured product can be improved. sex.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. The phthalic anhydride diisopropanol amide epoxy resin is characterized by comprising phthalic anhydride diisopropanol amide polyglycidyl ether, wherein the structure of the phthalic anhydride diisopropanol amide polyglycidyl ether is shown as a formula I:

the mass percentage of the phthalic anhydride diisopropanol amide polyglycidyl ether in the phthalic anhydride diisopropanol amide epoxy resin is more than or equal to 70 percent.

2. The phthalic anhydride diisopropanol amide epoxy resin according to claim 1, further comprising:

3. the phthalic anhydride diisopropanol amide epoxy resin as claimed in claim 1 or 2, wherein the phthalic anhydride diisopropanol amide epoxy resin has an epoxy value of 0.42 to 0.49eq/100 g.

4. The method for preparing the phthalic anhydride diisopropanol amide epoxy resin as claimed in any one of claims 1 to 3, comprising the steps of:

mixing phthalic anhydride, diisopropanolamine, a dehydrating agent and an organic solvent, performing an amidation reaction, removing a byproduct water, and removing the organic solvent and the dehydrating agent after the amidation reaction is finished to obtain phthalic anhydride diisopropanolamine;

the phthalic anhydride diisopropanol amide, the epoxy chloropropane and the inorganic base are subjected to open-close ring reaction by a one-step method under the action of a phase transfer catalyst, and after the reaction is finished, the phthalic anhydride diisopropanol amide epoxy resin is obtained by refining.

5. The method according to claim 4, wherein the molar ratio of the phthalic anhydride to the diisopropanolamine is 1: (2-2.3).

6. The method according to claim 4 or 5, wherein the temperature of the amidation reaction is 110 to 160 ℃ and the time is 5 to 9 hours.

7. The preparation process according to claim 4, wherein the molar ratio of the hydroxyl group of the phthalic anhydride diisopropanol amide, the epichlorohydrin and the inorganic base is 1: (6-20): (0.75 to 1.15); the mass of the phase transfer catalyst is 0.05-0.5% of the total mass of the phthalic anhydride diisopropanol amide, the epoxy chloropropane and the inorganic base.

8. The production method according to claim 4 or 7, wherein the phase transfer catalyst is benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride.

9. The preparation method according to claim 4 or 7, wherein the temperature of the one-step open-close loop reaction is 30-80 ℃, the pressure is normal pressure, and the time is 2-6 h.

10. Use of the phthalic anhydride diisopropanol amide epoxy resin according to any one of claims 1 to 3 or the phthalic anhydride diisopropanol amide epoxy resin prepared by the preparation method according to any one of claims 4 to 9 as a reinforcing material in epoxy resins.

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