Modified epoxy adhesive for snowboard and preparation method thereof

Abstract

The invention relates to the field of adhesives, and discloses a modified epoxy adhesive for a snowboard and a preparation method thereof, the modified epoxy adhesive for the snowboard comprises modified epoxy resin, modified graphene oxide, a curing agent, a flexibilizer and a diluent; the modified epoxy resin is prepared by grafting a carboxyl-terminated modifier and epoxy resin, and the carboxyl-terminated modifier is prepared by reacting phenyl phosphoryl dichloride with 2-hydroxymethyl aminoethanol, grafting octenyl succinic anhydride and further reacting with glutaric acid; the modified graphene oxide is prepared by carrying out functionalization treatment on graphene oxide by utilizing lysine, reacting allyl glycidyl ether with polymethylhydrosiloxane, and grafting with the functionalized graphene oxide. The adhesive is endowed with excellent mechanical property and adhesive property, the toughness is relatively high under normal and low temperature conditions, and the water resistance and the flame retardant property are improved at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to a modified epoxy adhesive for skis and a preparation method thereof. Background Art

[0002] Snowboards are a type of sports equipment used for skiing. During the preparation of snowboards, epoxy adhesives are generally used to bond dissimilar materials such as wood, fiber, plastic and metal. After the resin and curing agent are evenly mixed, they are applied layer by layer in the order of board bottom, high-performance fiber, wood core and board surface under manual conditions. Then, under certain pressure and temperature conditions, the composite snowboard is fixed in a specific mold to achieve bonding between the layers of material.

[0003] The performance of epoxy adhesives will be affected by environmental factors. They are prone to degradation under the influence of humidity and temperature. When exposed to a humid environment, water molecules can easily penetrate into the epoxy adhesive through the microcracks and pores in the epoxy adhesive, causing the adhesive material to plasticize, resulting in irreversible cracking, reducing mechanical properties, and premature peeling and damage at the bonding interface. In addition, when epoxy adhesives are used in low temperature environments, the cross-linked network structure of the resin molecules is frozen and concentrated, resulting in further increase in the brittleness of the resin, and its impact resistance and toughness are greatly reduced, causing epoxy resins to often crack in alternating environments of normal and low temperatures, limiting their application. Summary of the invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a modified epoxy adhesive for skis and a preparation method thereof. By adding modified epoxy resin and modified graphene oxide, the adhesive is given excellent mechanical properties and bonding properties, and has high toughness under normal and low temperature conditions, while water resistance and flame retardancy are improved.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A modified epoxy adhesive for a snowboard, comprising the following components in parts by weight: 70-90 parts of a modified epoxy resin, 15-20 parts of modified graphene oxide, 15-30 parts of a curing agent, 2-5 parts of a toughening agent, and 10-20 parts of a diluent; The modified epoxy resin is prepared by grafting a terminal carboxyl modifier with an epoxy resin, wherein the terminal carboxyl modifier is prepared by grafting octenyl succinic anhydride with phenylphosphoryl dichloride and 2-hydroxymethylaminoethanol after a substitution reaction, and further undergoing a polyesterification reaction with glutaric acid; the modified graphene oxide is prepared by functionalizing graphene oxide with lysine, and grafting functionalized graphene oxide with allyl glycidyl ether and polymethyl hydrogen siloxane after a silylation reaction.

[0006] Preferably, the epoxy resin is one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0007] Preferably, the toughening agent is SEBS; the curing agent is one or more combinations of aliphatic amine curing agent, alicyclic amine curing agent, aromatic amine curing agent, polyether amine curing agent, and polyamide curing agent; the diluent is one or more combinations of ethylene glycol diglycidyl ether, dodecyl glycidyl ether, benzyl glycidyl ether, and neopentyl glycol diglycidyl ether.

[0008] Preferably, the method for preparing the modified graphene oxide comprises the following steps: (1) Allyl glycidyl ether was placed in a reactor, heated to 105-120°C, nitrogen was introduced and kept warm for 20-30 min, cooled to 75-85°C, chloroplatinic acid catalyst and polymethylhydrogensiloxane were added, and the mixture was reacted at 105-120°C for 3-5 h to prepare an epoxy silicone monomer; (2) ultrasonically dispersing graphene oxide in deionized water to obtain a dispersion, dissolving lysine in deionized water, adjusting the pH value to 7-7.5 with a sodium hydroxide solution, then adding the dispersion to mix evenly, placing at 30-45° C. for reaction for 18-24 hours, and washing and drying after the reaction to obtain functionalized graphene oxide; (3) Functionalized graphene oxide is ultrasonically dispersed in acetone, epoxy silicone monomer and triphenylphosphine are added, and the mixture is reacted at 85-105°C for 12-16 hours. After the reaction is completed, the modified graphene oxide is prepared by filtering, washing and drying.

[0009] Preferably, in step (3), the mass ratio of the functionalized graphene oxide to the epoxy silicone monomer is 1:0.4-0.7.

[0010] Preferably, the preparation method of the modified epoxy resin comprises the following steps: A. Phenylphosphoryl dichloride and 2-hydroxymethylaminoethanol are placed in a reactor, tetrahydrofuran solvent is added, and the reaction is stirred for 5 to 7 hours. During the reaction, triethylamine is added in batches to remove the hydrogen chloride produced by the reaction. After the reaction is completed, the terminal hydroxyl intermediate is prepared by suction filtration, rotary evaporation, and drying; B. Place the terminal hydroxyl intermediate, octenyl succinic anhydride, p-toluenesulfonic acid and N,N-dimethylformamide in a reactor, stir and react at 110-125° C. for 4-6 hours, and after the reaction is completed, perform vacuum distillation and drying to obtain a modified terminal hydroxyl intermediate; C. Take the modified terminal hydroxyl intermediate and glutaric acid in a reactor, place it at 120-135° C. and stir to react for 5-7 hours. After the reaction is completed, take out the product and dry it to prepare a terminal carboxyl modifier; D. Place the terminal carboxyl modifier and epoxy resin in a reactor, place them at 100-120°C and stir to react for 5-6 hours. After the reaction is completed, take out the product and dry it to prepare a modified epoxy resin.

[0011] Preferably, in step A, the molar ratio of phenylphosphoryl dichloride to 2-hydroxymethylaminoethanol is 1:2-2.6.

[0012] Preferably, in step B, the molar ratio of the terminal hydroxyl intermediate to octenyl succinic anhydride is 1:2-2.5.

[0013] Preferably, in step C, the molar ratio of the modified terminal hydroxyl intermediate to glutaric acid is 1:1.3-1.5.

[0014] The method for preparing the modified epoxy adhesive for skis as described above comprises the following steps: S1, taking parts by weight of modified epoxy resin and toughening agent, mixing them and preheating them at 60-80° C. for 20-30 min to prepare a premix; S2, adding parts by weight of modified graphene oxide, a curing agent, and a diluent to the premix and stirring evenly to prepare a mixture; S3. The mixture is transferred to a grinder for grinding and dispersion, and then degassed in a vacuum environment for 20 to 60 minutes to prepare a modified epoxy adhesive.

[0015] Beneficial effects of the present invention: The present invention utilizes allyl glycidyl ether and polymethyl hydrogen siloxane to undergo a silylation reaction to prepare an epoxy silicone monomer. At the same time, the present invention utilizes a carboxyl group in a graphene oxide structure to react with an amino group in a lysine structure to prepare functionalized graphene oxide. Then, the epoxy group in the epoxy silicone monomer structure reacts with the carboxyl group in the functionalized graphene oxide structure to prepare modified graphene oxide. Among them, graphene oxide, as a nanofiller, has the advantages of impermeability to oxygen and water and high specific surface area. Grafting epoxy silicone monomers into the interlayer of graphene oxide can not only increase the interlayer spacing of graphene oxide and make the propagation path of oxygen and water tortuous, but also increase the contact area between graphene oxide and epoxy resin, and improve the compatibility between modified graphene oxide and epoxy resin. Epoxy resin can be co-cured with modified graphene oxide and curing agent to enhance cross-linking density and improve waterproof and toughening effects. In addition, the grafting of epoxy silicone monomers introduces Si-O-Si flexible chain segments to form a network structure with more free volume, which reduces stress concentration in the cured product, thereby improving the normal and low temperature toughness of epoxy resin adhesives.

[0016] The invention utilizes chlorine atoms in a phenylphosphoryl dichloride structure and hydroxyl groups in a 2-hydroxymethylaminoethanol structure to undergo substitution reaction to prepare a terminal hydroxyl intermediate containing phosphorus and nitrogen elements, thereby improving the flame retardancy of an adhesive, and then a -NH group in the terminal hydroxyl intermediate structure is grafted with an acid anhydride group in a hydrophobic substance octenyl succinic anhydride structure to prepare a modified terminal hydroxyl intermediate, thereby improving the hydrophobicity of the adhesive, and further utilizes glutaric acid to undergo polyesterification reaction with the terminal hydroxyl intermediate to prepare a terminal carboxyl modifier containing carboxyl groups at both ends, and then the carboxyl group thereof is reacted with an epoxy group in an epoxy resin structure to prepare a modified epoxy resin, and the grafting of the terminal carboxyl modifier introduces flexible chains, hydrophobic long chains, phosphorus atoms and nitrogen atoms into a three-dimensional network structure of the epoxy resin, thereby achieving the effects of toughening, improving water resistance and flame retardancy. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1 A method for preparing modified graphene oxide comprises the following steps: (1) 180 g of allyl glycidyl ether was placed in a reactor, heated to 110°C, introduced with nitrogen and kept warm for 30 min, cooled to 80°C, added with 280 uL of chloroplatinic acid catalyst and 363 g of polymethylhydrogensiloxane, and reacted at 110°C for 5 h to prepare an epoxy silicone monomer; (2) 1 g of graphene oxide was ultrasonically dispersed in 160 mL of deionized water to obtain a dispersion, 2.5 g of lysine was dissolved in 40 mL of deionized water, and the pH value was adjusted to 7.4 using a 4 mg / mL sodium hydroxide solution, and then the dispersion was added and mixed evenly, and the mixture was placed at 40 ° C for 20 h. After the reaction was completed, the functionalized graphene oxide was prepared by washing and drying; (3) Take 1 g of functionalized graphene oxide and ultrasonically disperse it in 40 mL of acetone, add 0.5 g of epoxy silicone monomer and 0.002 g of triphenylphosphine, and react at 95 °C for 14 h. After the reaction is completed, filter, wash and dry to prepare modified graphene oxide.

[0019] Example 2 A method for preparing a modified epoxy resin comprises the following steps: A. Take 19.5g of phenylphosphoryl dichloride and 22.8g of 2-hydroxymethylaminoethanol in a reactor, add 100mL of tetrahydrofuran solvent and stir to react for 6h. During the reaction, triethylamine is added in batches to remove the hydrogen chloride produced by the reaction. After the reaction is completed, it is filtered, rotary evaporated and dried to prepare a terminal hydroxyl intermediate; B. 30.4 g of the terminal hydroxyl intermediate, 46.3 g of octenyl succinic anhydride, 0.45 g of p-toluenesulfonic acid and 100 mL of N,N-dimethylformamide were placed in a reactor, stirred and reacted at 120° C. for 6 h. After the reaction was completed, the modified terminal hydroxyl intermediate was prepared by vacuum distillation and drying; C. Take 28.9 g of the modified terminal hydroxyl intermediate and 6.87 g of glutaric acid in a reactor, place it at 125° C. and stir for 6 hours. After the reaction is completed, take out the product and dry it to prepare a terminal carboxyl modifier; D. Take 15.2g of terminal carboxyl modifier and 30.4g of epoxy resin CYD-128 into a reactor, place it at 120°C and stir to react for 6h. After the reaction is completed, take out the product and dry it to prepare a modified epoxy resin.

[0020] Example 3 A modified epoxy adhesive for a snowboard comprises the following components in parts by weight: 72 parts of the modified epoxy resin prepared in Example 2, 15 parts of the modified graphene oxide prepared in Example 1, 15 parts of diaminodiphenylmethane as a curing agent, 2 parts of SEBS as a toughening agent, and 12 parts of ethylene glycol diglycidyl ether as a diluent.

[0021] The preparation method of the modified epoxy adhesive for skis comprises the following steps: S1, taking parts by weight of modified epoxy resin and toughening agent, mixing them and preheating them at 75° C. for 30 min to prepare a premix; S2, adding parts by weight of modified graphene oxide, a curing agent, and a diluent to the premix and stirring evenly to prepare a mixture; S3. The mixture is transferred to a grinder for grinding and dispersion, and then degassed in a vacuum environment for 30 minutes to prepare a modified epoxy adhesive.

[0022] Example 4 A modified epoxy adhesive for a snowboard comprises the following components in parts by weight: 80 parts of the modified epoxy resin prepared in Example 2, 17 parts of the modified graphene oxide prepared in Example 1, 22 parts of diaminodiphenylmethane as a curing agent, 4 parts of SEBS as a toughening agent, and 16 parts of ethylene glycol diglycidyl ether as a diluent.

[0023] The preparation method of the modified epoxy adhesive for skis is the same as that in Example 3.

[0024] Example 5 A modified epoxy adhesive for a snowboard comprises the following components in parts by weight: 88 parts of the modified epoxy resin prepared in Example 2, 20 parts of the modified graphene oxide prepared in Example 1, 28 parts of diaminodiphenylmethane as a curing agent, 5 parts of SEBS as a toughening agent, and 20 parts of ethylene glycol diglycidyl ether as a diluent.

[0025] The preparation method of the modified epoxy adhesive for skis is the same as that in Example 3.

[0026] Comparative Example 1 A modified epoxy adhesive for a snowboard comprises the following components in parts by weight: 888 parts of epoxy resin CYD-12, 20 parts of modified graphene oxide prepared in Example 1, 28 parts of diaminodiphenylmethane as a curing agent, 5 parts of SEBS as a toughening agent, and 20 parts of ethylene glycol diglycidyl ether as a diluent.

[0027] The preparation method of the modified epoxy adhesive for skis is the same as that in Example 3.

[0028] Comparative Example 2 A modified epoxy adhesive for a snowboard comprises the following components in parts by weight: 88 parts of the modified epoxy resin prepared in Example 2, 20 parts of graphene oxide, 28 parts of diaminodiphenylmethane as a curing agent, 5 parts of SEBS as a toughening agent, and 20 parts of ethylene glycol diglycidyl ether as a diluent.

[0029] The preparation method of the modified epoxy adhesive for skis is the same as that in Example 3.

[0030] Performance Testing The modified epoxy adhesive prepared in Examples 3-5 and Comparative Examples 1-2 was used to bond the PU film material on the surface of the snowboard and the P-Tex material on the bottom of the snowboard fixed on the fixture, and was cured for 40 minutes under 0.2MPa and 75°C. The performance test was carried out and the data results are shown in Table 1.

[0031] Table 1 Test results of sample performance Category Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Tensile strength / MPa 72.4 76.3 78.7 66.8 51.2 Impact strength (KJ / m-2) 28.8 29.2 29.6 22.7 17.4 -20℃ impact strength (KJ / m-2) 26.6 27.1 27.2 20.1 11.2 Peel strength of board material (KN / m) 2.3 2.7 2.5 2.3 2.1 Peel strength of bottom material (KN / m) 3.4 3.9 3.7 3.6 3.2 -20℃ board material peeling strength (KN / m) 2.0 2.5 2.2 2.0 1.6 -20℃ peel strength of bottom material (KN / m) 3.1 3.7 3.5 3.2 2.4 Water contact angle / ° 94.5 95.2 97.8 71.2 95.7 Limiting oxygen index / % 29.2 30.6 32.2 25.6 30.2 As can be seen from the data in Table 1, the modified epoxy adhesives prepared in Examples 3-5 of the present invention have excellent mechanical properties and bonding properties, high toughness under normal and low temperature conditions, and improved water resistance and flame retardancy. In Comparative Example 1, the epoxy resin was not modified, and the tensile strength, impact strength, water contact angle and limiting oxygen index measured were significantly different from those of Examples 3-5. The reason is that the flexible chain, hydrophobic long chain, phosphorus atom and nitrogen atom were not introduced into the three-dimensional network structure of the epoxy resin, resulting in reduced performance. In Comparative Example 2, the graphene oxide was not modified, and the tensile strength, impact strength under normal and low temperature conditions and peel strength under low temperature conditions were lower than those of Examples 3-5, indicating that modifying the graphene oxide can improve the mechanical properties and low temperature resistance of the adhesive.

[0032] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0033] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A modified epoxy adhesive for a snowboard, characterized in that: The invention comprises the following components in parts by weight: 70-90 parts of modified epoxy resin, 15-20 parts of modified graphene oxide, 15-30 parts of curing agent, 2-5 parts of toughening agent and 10-20 parts of diluent; The modified epoxy resin is prepared by grafting a terminal carboxyl modifier with an epoxy resin, wherein the terminal carboxyl modifier is prepared by grafting octenyl succinic anhydride with phenylphosphoryl dichloride and 2-hydroxymethylaminoethanol after a substitution reaction, and further undergoing a polyesterification reaction with glutaric acid; the modified graphene oxide is prepared by functionalizing graphene oxide with lysine, and grafting functionalized graphene oxide with allyl glycidyl ether and polymethyl hydrogen siloxane after a silylation reaction.

2. The modified epoxy adhesive for snowboard according to claim 1, characterized in that: The epoxy resin is one of bisphenol A epoxy resin and bisphenol F epoxy resin.

3. The modified epoxy adhesive for snowboard according to claim 1, characterized in that: The toughening agent is SEBS; the curing agent is one or more combinations of aliphatic amine curing agent, alicyclic amine curing agent, aromatic amine curing agent, polyether amine curing agent, and polyamide curing agent; the diluent is one or more combinations of ethylene glycol diglycidyl ether, dodecyl glycidyl ether, benzyl glycidyl ether, and neopentyl glycol diglycidyl ether.

4. The modified epoxy adhesive for snowboard according to claim 1, characterized in that: The preparation method of the modified graphene oxide comprises the following steps: (1) Allyl glycidyl ether was placed in a reactor, heated to 105-120°C, nitrogen was introduced and kept warm for 20-30 min, cooled to 75-85°C, chloroplatinic acid catalyst and polymethylhydrogensiloxane were added, and the mixture was reacted at 105-120°C for 3-5 h to prepare an epoxy silicone monomer; (2) ultrasonically dispersing graphene oxide in deionized water to obtain a dispersion, dissolving lysine in deionized water, adjusting the pH value to 7-7.5 with a sodium hydroxide solution, then adding the dispersion to mix evenly, placing at 30-45° C. for reaction for 18-24 hours, and washing and drying after the reaction to obtain functionalized graphene oxide; (3) Functionalized graphene oxide is ultrasonically dispersed in acetone, epoxy silicone monomer and triphenylphosphine are added, and the mixture is reacted at 85-105°C for 12-16 hours. After the reaction is completed, the modified graphene oxide is prepared by filtering, washing and drying.

5. The modified epoxy adhesive for snowboard according to claim 4, characterized in that: In the step (3), the mass ratio of the functionalized graphene oxide to the epoxy silicone monomer is 1:0.4-0.

7.

6. The modified epoxy adhesive for snowboard according to claim 1, characterized in that: The preparation method of the modified epoxy resin comprises the following steps: A. Phenylphosphoryl dichloride and 2-hydroxymethylaminoethanol are placed in a reactor, tetrahydrofuran solvent is added, and the reaction is stirred for 5 to 7 hours. During the reaction, triethylamine is added in batches to remove the hydrogen chloride produced by the reaction. After the reaction is completed, the terminal hydroxyl intermediate is prepared by suction filtration, rotary evaporation, and drying; B. Place the terminal hydroxyl intermediate, octenyl succinic anhydride, p-toluenesulfonic acid and N,N-dimethylformamide in a reactor, stir and react at 110-125° C. for 4-6 hours, and after the reaction is completed, perform vacuum distillation and drying to obtain a modified terminal hydroxyl intermediate; C. Take the modified terminal hydroxyl intermediate and glutaric acid in a reactor, place it at 120-135° C. and stir to react for 5-7 hours. After the reaction is completed, take out the product and dry it to prepare a terminal carboxyl modifier; D. Place the terminal carboxyl modifier and epoxy resin in a reactor, place them at 100-120°C and stir to react for 5-6 hours. After the reaction is completed, take out the product and dry it to prepare a modified epoxy resin.

7. The modified epoxy adhesive for snowboard according to claim 6, characterized in that: In the step A, the molar ratio of phenylphosphoryl dichloride to 2-hydroxymethylaminoethanol is 1:2-2.

6.

8. The modified epoxy adhesive for snowboards according to claim 6, characterized in that: In the step B, the molar ratio of the terminal hydroxyl intermediate to octenyl succinic anhydride is 1:2-2.

5.

9. The modified epoxy adhesive for snowboards according to claim 6, characterized in that: In the step C, the molar ratio of the modified terminal hydroxyl intermediate to glutaric acid is 1:1.3-1.

5.

10. A method for preparing a modified epoxy adhesive for a snowboard according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, taking parts by weight of modified epoxy resin and toughening agent, mixing them and preheating them at 60-80° C. for 20-30 min to prepare a premix; S2, adding parts by weight of modified graphene oxide, a curing agent, and a diluent to the premix and stirring evenly to prepare a mixture; S3. The mixture is transferred to a grinder for grinding and dispersion, and then degassed in a vacuum environment for 20 to 60 minutes to prepare a modified epoxy adhesive.