KR100511139B1 - 4-functionality hybrid epoxy resin composition - Google Patents

Abstract

The present invention relates to a tetrafunctional hybrid epoxy resin composition, in particular, including a tetrafunctional epoxy resin (TGDDM) and epoxidized soybean oil (ESO), low-cost hybrid epoxy resin having mechanical properties superior to conventional TGDDM epoxy resin It provides an epoxy resin composition that can be provided.

Description

4-functional hybrid epoxy resin composition {4-FUNCTIONALITY HYBRID EPOXY RESIN COMPOSITION}

The present invention relates to a tetrafunctional hybrid epoxy resin composition having excellent mechanical properties, and in particular, a tetrafunctional epoxy resin and an epoxidized soybean oil (hereinafter, referred to as "ESO") are hybridized to each other. The present invention relates to an epoxy resin composition capable of low-cost production of a tetrafunctional hybrid epoxy resin having better mechanical properties than a widely used TGDDM (4,4'-tetradiglycidyldiaminodiphenolmethane) epoxy resin.

Conventional epoxy resin hybrids were prepared by hybridizing an epoxy resin with a thermosetting resin or a thermoplastic resin only to improve mechanical or thermal properties (P. Musto et al., J. Appl. Polym. Sci., 1998, 69, 1029).

However, such a conventional epoxy resin hybrid has a problem in that the mechanical properties are greatly improved while the thermal properties are greatly reduced and manufacturing costs are high.

Therefore, there is an urgent need to develop an epoxy resin hybrid composition having excellent mechanical properties and low manufacturing cost.

Accordingly, an object of the present invention is to provide a tetrafunctional hybrid epoxy resin composition that can hybridize a tetrafunctional epoxy resin and an ESO to produce a hybrid epoxy resin having superior mechanical properties than a conventional TGDDM epoxy resin at low cost.

In order to achieve the above object, the present invention provides a tetrafunctional hybrid epoxy resin composition is a hybrid of the TGDDM epoxy resin and ESO.

Hereinafter, the present invention will be described in detail.

ESOs contained in the tetrafunctional hybrid epoxy resin composition according to the present invention are represented by the following Chemical Formula 1.

ESO of Formula 1 may be prepared by oxidizing soybean oil with an acid and hydrogen peroxide solution, for example, in a solvent in the presence of Amberlite (Amberlite) as shown in Scheme 1 below.

In Reaction Scheme 1, the solvent, acid, hydrogen peroxide (30%) and amberlite are each weight ratio in the range of 1: 0.2 to 0.6, 1: 0.2 to 0.5, 1: 0.6 to 1.1, and 1: 0.15 to 0.35 with respect to soybean oil. Can be used as Examples of the solvent include toluene and tetrahydrofuran (THF).

The reaction is preferably carried out for 6 to 9 hours in the temperature range of 45 to 60 ℃ in terms of the maximum reaction rate and the resin viscosity. When the reaction temperature is 45 ℃ or less or the reaction time is 6 hours or less, the reaction is slowed to obtain a resin having a low epoxidation degree. Resin is prepared.

The tetrafunctional hybrid epoxy resin composition of the present invention comprises 80 to 99% by weight of TGDDM epoxy resin and 1 to 20% by weight of ESO.

As can be seen from the results shown in Figures 3 and 4, when the content of ESO is less than 1% by weight, the mechanical properties of the cured product of the cured hybrid epoxy resin composition are larger than those of the cured product of the conventional TGDDM epoxy resin composition. There is no increase, and when the content of ESO exceeds 20% by weight, a sharp decrease in physical properties occurs. Therefore, the content of ESO of the tetrafunctional hybrid epoxy resin composition according to the present invention is preferably 1 to 20% by weight, in particular 5 to 10% by weight, based on the total weight of the composition.

The tetrafunctional hybrid epoxy resin composition according to the present invention may be prepared by reacting diaminodiphenylmethane (DDM) as a curing agent in an equivalent ratio of 1: 1. After curing, the cured product of the tetrafunctional hybrid epoxy resin composition exhibits better mechanical properties (critical stress intensity factor and flexural strength) than the conventional TGDDM epoxy resin.

The invention is described in more detail in the following examples, although the scope of the invention is not limited thereto.

Example 1

100 g of soybean oil (0.14 mole, purity 98%, Wako Chemical, Japan), 25.2 g of glacial acetic acid (0.42 mole, Wako Chemical, Japan), 25 g of amber light and 40 g of toluene were placed in a reactor equipped with a stirrer, a thermometer and a condenser, and the temperature was increased to 55 ° C. After holding, 79.4 g (0.7 mol, Wako Chemical Co., Ltd.) of 30% hydrogen peroxide solution was added thereto and reacted for 7 hours to prepare ESO of Chemical Formula 1.

After the reaction, the prepared resin was filtered and washed with distilled water until the pH reaches 7. The organic phase was dried over anhydrous sodium sulfate and then filtered. Toluene was removed by vacuum distillation of the filtered ESO at 80 ° C. to obtain an ESO having a weight average molecular weight of 1527 in a yield of 89% or more.

Example 2

The reaction was carried out for 8 hours in the same manner as in Example 1 except that the reaction temperature was maintained at 50 ° C. to obtain an ESO epoxy resin having a weight average molecular weight of 1491 in a yield of 88% or more.

Example 3

Diaminodi as a curing agent in a hybrid epoxy resin composition obtained by mixing 98 wt% of a tetrafunctional epoxy resin TGDDM (LG Chemical Co., Ltd., density 1.17 g / cm 3, viscosity 14000 cps) with 2 wt% of the ESO epoxy resin obtained in Example 1 Phenylmethane (DDM; Aldrich) was added in a 1: 1 equivalent ratio to prepare a specimen. At this time, curing conditions were 1 hour at 110 degreeC, 2 hours at 140 degreeC, and 1 hour at 170 degreeC.

Example 4

Hybrid epoxy in the same manner as in Example 3, except that 90 wt% of the tetrafunctional epoxy resin TGDDM (LG Chemical Co., Ltd., density 1.17 g / cm 3, viscosity 14000 cps) and 10 wt% of ESO obtained in Example 1 were used. A cured specimen of the resin composition was prepared.

Example 5

Hybrid epoxy in the same manner as in Example 3, except that 85 wt% of the tetrafunctional epoxy resin TGDDM (LG Chemical Co., Ltd., density 1.17 g / cm 3, viscosity 14000 cps) and 15 wt% of ESO obtained in Example 1 were used. A cured specimen of the resin composition was prepared.

Example 6

Hybrid epoxy in the same manner as in Example 3, except that 80 wt% of the tetrafunctional epoxy resin TGDDM (LG Chemical Co., Ltd., density 1.17 g / cm 3, viscosity 14000 cps) and 20 wt% of ESO obtained in Example 1 were used. A cured specimen of the resin composition was prepared.

Example 7

A cured specimen of the hybrid epoxy resin composition was prepared in the same manner as in Example 4 except that the ESO obtained in Example 2 was used.

Comparative example

Specimens were prepared using a cured general purpose TGDDM epoxy resin (LG Chem).

Measurement of physical properties

The physical properties of the cured specimens and the comparative example specimens of the hybrid epoxy resin compositions prepared in Examples 3 to 7 were measured by the following method.

(1) Curing Activation Energy (E _a )

The cure rate is a function of temperature, and assuming that the rate constant is based on the Arhenius equation, the cure activation energy ( E _a ) can be obtained using the Flynn-Wall-Ozawa equation.

Where q is the temperature increase rate, A is the exponential factor, T _P is the temperature at the maximum exothermic peak, g (α) is a term depending on the conversion rate, and R is a gas constant.

Based on the above equation, after calculating the maximum heating temperature for each heating rate, ln q The hardening activation energy ( E _a ) can be calculated from the slope (1.052 Ea / R ) of the graph by the relationship of 1 / T _p .

(2) mechanical properties

end. Critical Stress Intensity Factor (K _IC )

The critical stress intensity factor (K _IC ) representing the crack growth resistance of the cured specimen can be obtained using the following equation.

Where P is the load, L is the distance between the supports, b is the width of the specimen, d is the thickness of the specimen, and Y is the geometric factor depending on the length of the crack, the location of the crack, and the loading method.

The critical stress intensity factor of the cured specimens was measured by using a universal test machine (Universal Test Machine # 1125) with a strain rate of 2 mm / min and a ratio of the distance between the supports and the thickness of the specimen at 4: 1.

I. Flexural strength ( σ _f )

The flexural strength ( σ _f ) of the cured specimen can be obtained using the following equation.

Where P is the load, L is the distance between the supports, b is the width of the specimen, and d is the thickness of the specimen.

The flexural strength of the cured specimens was measured by using a universal test machine (Universal Test Machine # 1125) with a strain rate of 2.1 mm / min and a ratio of the distance between the supports and the thickness of the specimen at 16: 1.

The physical property values of the cured specimens and the comparative example specimens of the hybrid epoxy resins prepared in Examples 3 to 7 thus measured are shown in Table 1 and FIGS. 2 to 4.

Curing activation energy (kJ / mol) Critical stress intensity factor (kPa · m ^1/2 ) Flexural strength (kPa) Example 3 56.2 1.53 (+ 18%) 120.5 (+ 8%) Example 4 57.0 2.03 (+ 56%) 129.4 (+ 16%) Example 5 55.6 1.99 (+ 50%) 106.2 (-5%) Example 6 53.7 2.0 (+ 54%) 96.4 (-13%) Example 7 56.9 1.99 (+ 53%) 129.5 (+ 16%) Comparative example 55.1 1.3 111.4

As can be seen in Table 1 and Figures 2 to 4, the tetrafunctional hybrid epoxy resin composition of the present invention has a higher critical stress intensity factor and flexural strength than conventional general-purpose TGDDM epoxy resin. Therefore, the tetrafunctional hybrid epoxy resin composition of the present invention is excellent in mechanical properties compared to the conventional epoxy resin.

Since the tetrafunctional hybrid epoxy resin composition prepared according to the method of the present invention has excellent mechanical properties and low manufacturing cost, it can be advantageously used to prepare a composite material by replacing it with a conventional TGDDM epoxy resin.

FIG. 1 shows the results of infrared spectroscopy (FT-IR) of monomer soybean oil and ESO synthesized in Example 1. FIG.

Figure 2 shows the heating curve according to the ESO content of the cured specimen and the comparative example specimen of the hybrid epoxy resin composition prepared in Examples 3 to 6.

Figure 3 shows the critical stress intensity factor (K _IC ) according to the ESO content of the cured specimen and the comparative example specimen of the hybrid epoxy resin composition prepared in Examples 3 to 6.

Figure 4 shows the flexural strength (σ _f ) according to the ESO content of the cured specimen and the comparative example specimen of the hybrid epoxy resin composition prepared in Examples 3 to 6.

Claims (5)

A tetrafunctional hybrid epoxy resin composition comprising 80 to 99% by weight of tetrafunctional epoxy resin (TGDDM) and 1 to 20% by weight of epoxidized soybean oil (ESO). The method of claim 1, ESO has a structure of the following formula (1), tetrafunctional hybrid epoxy resin composition. Formula 1 The method of claim 1, ESO is produced by oxidizing soybean oil in a solvent in the presence of Amberlite (Amberlite), tetrafunctional hybrid epoxy resin composition. The method of claim 3, wherein The tetrafunctional hybrid epoxy resin composition, characterized in that the reaction was carried out for 6 to 9 hours in the temperature range of 45 to 60 ℃. A composite obtained by curing the tetrafunctional hybrid epoxy resin composition according to any one of claims 1 to 4 as a matrix resin and curing with an amine curing agent.