TW201336900A - Silicone composite with high strength and method for manufacturing the same - Google Patents

Abstract

A silicone composite and method for manufacturing the same are disclosed. The major components of the silicone composite comprise a silanized graphene and a silicone matrix. The unique properties of the silanized graphene lead an improvement of the mechanical strength property of the silicone composite.

Description

High-strength silicone composite material and manufacturing method thereof

This invention relates to a silicone composite, and more particularly to a high strength silicone composite.

Silicone materials have been widely used in a variety of high value-added industries, such as electronics, automotive manufacturing or traditional industries. Because silicone is a multifunctional and versatile polymer material, it has good insulation, thermal stability, elasticity and hydrophobicity, so it is often used as an interface thermal conductive element, heat-resistant sealing material or protective element.

In industrial applications, although the silicone rubber itself has the above various advantages, it is limited by the mechanical strength and thermal conductivity of the silicone rubber itself, and cannot expand and extend the industrial application range of the silicone rubber. Therefore, in order to break through the limitations of silicone itself, the past literature has published a variety of silicone composites by doping different materials. For example, U.S. Patent Application Publication No. US 2010/01296254 A1 discloses a silicone material doped with oxidized or acidified nano carbon fibers. However, neither the oxidized or acidified nanocarbon fibers nor the hydrophilic materials can significantly improve the mechanical strength and thermal conductivity of the silicone. In addition, since the silicone itself is hydrophobic, if a hydrophilic material is doped, the hydrophilic material and the silicone may be unevenly dispersed.

Therefore, it is necessary to provide a silicone composite material having high strength and a method of manufacturing the same.

The present invention provides a method of producing a silicone composite material. According to an embodiment of the present invention, the decaneization reaction of graphene is first carried out to form a decylated graphene having a siloxane alkyl branch. The above decylated graphene is then dispersed in the silicone component to form a silicone dispersion containing decylated graphene. Finally, the above-mentioned silicone dispersion is solidified to form a silicone composite.

According to an embodiment of the present invention, in the step of curing the silicone dispersion, the hardener is first added to the silicone dispersion to form a curing reaction solution. Next, the curing reaction liquid is first subjected to a vacuum defoaming operation, and is injected into a mold to be heated and solidified to form the above-mentioned silicone composite material.

In the above step of heating and curing the reaction liquid, the heating temperature may be from 100 ° C to 150 ° C, or preferably from 110 ° C to 130 ° C.

According to another embodiment of the present invention, the present invention provides a method of producing decylated graphene in the above-described silicone composite. First, a carbon-carbon double bond (C=C) in graphene is broken by an oxidizing agent and a strong acid to form a first graphene oxide having an oxygen-containing group. Next, the oxime coupling agent is mixed with the above first graphene oxide and reacted to form a second graphene oxide having a decyloxyalkyl group. Finally, under the action of the reducing agent, the oxygen-containing group in the second graphene oxide which is not reacted with the oxirane coupling agent is reduced to a carbon-carbon double bond (C=C) to form a decyloxy group. Decanolated graphene.

According to an embodiment of the present invention, the oxidizing agent is potassium permanganate (KMnO ₄ ) and sodium nitrite (NaNO ₂ ), the strong acid is sulfuric acid (H ₂ SO ₄ ), and the reducing agent comprises hydrazine (N ₂ H ₄ ). The above oxygen-containing group may be at least one selected from the group consisting of a hydroxyl group, an epoxy group, a carbonyl group, and a carboxylic acid group. The above-mentioned oxime coupling agent may have a chemical structural formula of RSi[O(CH ₃ )] _a (CH ₃ ) _3-a , wherein R is a C3-C18 alkyl group and a is an integer of 0 to 3. Further, R of the above-mentioned oxime coupling agent is preferably a C6-C10 alkyl group.

According to an embodiment of the present invention, the method for producing the above-described decadiene graphene is obtained by mixing and reacting a cerium oxygen coupling agent with a first graphene oxide by an ultrasonic vibration method.

According to another embodiment of the present invention, the method for manufacturing the above-mentioned silicone composite material utilizes ultrasonic vibration method and high-speed mechanical stirring method to uniformly mix the germane-alkylene graphene and the tannin component, and perform defoaming operation in a vacuum to form A tantalum dispersion of decadiated graphene is uniformly mixed. The main component of the above-mentioned silicone component comprises polydimethylsiloxane, and its chemical structural formula may be H ₂ CCHSi(CH ₃ ) ₂ O[SiO(CH ₃ ) ₂ ] _n Si(CH ₃ ) ₂ CHCH ₂ . Where n is an integer from 50 to 500 and its viscosity is between 2500 mPa‧s and 4000 mPa‧s.

According to an embodiment of the present invention, the main component of the hardener comprises a decane coupling agent containing a platinum catalyst, and the chemical structure formula of the decane coupling agent is R'SiO(CH ₃ ) ₂ [SiO(CH ₃ ) ₂ ] _k [SiO(CH ₃ )H] _m SiR'. Wherein R' is methyl (CH ₃ ) or hydrogen (H), k is an integer from 1 to 30, and m is an integer from 1 to 30. The volume ratio of the silicone component to the above hardener is 10:1.

According to an embodiment of the present invention, the above decylalkylene of the decylated graphene has a comb-like solid structure.

According to an embodiment of the present invention, the decylalkyl group of the decylated graphene dispersed in the silicone composite material is interlaced with each of the decylated graphene to form a network structure.

Further, the present invention provides a silicone composite material produced by the above manufacturing method. According to another embodiment of the invention, it comprises a cured silicone substrate and a decylated graphene having a decyloxyalkyl group. The above decylated graphene is dispersed in a cured silicone substrate, and the oxoalkyl groups between the respective decylated graphenes are interdigitated to form a network structure.

According to an embodiment of the present invention, the content of the above decylated graphene is from 0.5 wt% to 5 wt%.

According to an embodiment of the present invention, the mechanical strength of the silicone composite material is considered to be, and the preferred content of the above-described decylated graphene is from 0.75 wt% to 2 wt%.

In order to provide the reader with a better understanding of the silicone composites provided by the present invention, several embodiments of the invention are enumerated below. However, these examples are for illustrative purposes only and do not impose any limitation on the scope and application of the invention. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and the scope of the invention is fully described by those skilled in the art. In the drawings, the shapes and dimensions may be exaggerated, and the same reference numerals will be used to designate the same or similar components.

Method for manufacturing silicone rubber composite material

1 is a flow chart of a method for manufacturing a silicone composite material according to an embodiment of the present invention. 2 is a flow chart of a method for producing decylated graphene according to an embodiment of the present invention.

In the step 110 shown in Fig. 1, first, the decylated graphene is prepared, and the manufacturing steps thereof are shown in Fig. 2. In Fig. 2, the preparation of the decylated graphene requires sequential oxidation of the graphene (step 210), decaneization (step 220), and reduction (step 230).

In the oxidation step 210 of FIG. 2, graphene is subjected to an oxidizing agent under acidic conditions to cleave the carbon-carbon double bond (C=C) of graphene to form a first graphene oxide having an oxygen-containing group. . And the first graphene oxide can be purified by centrifugation and filtration. In the oxidation step 210, the oxidizing agent used may be potassium permanganate (KMnO ₄ ) and sodium nitrite (NaNO ₂ ), and the acidic conditions are composed of concentrated sulfuric acid (98 wt%) as a solvent. The oxygen-containing group of the first graphene oxide is at least one selected from the group consisting of a hydroxyl group, an epoxy group, a carbonyl group, and a carboxylic acid group.

According to an embodiment of the present invention, in the oxidation step 210, the oxidation reaction of the graphene described above is carried out by a high temperature stirring reflux reaction method. The reaction temperature can be from 80 ° C to 120 ° C, and the optimum reaction temperature is from 90 ° C to 110 ° C. The reaction time can be from 1 hour to 5 hours, and the optimum reaction is from 2 hours to 4 hours.

In the oximation step 220 of FIG. 2, the first graphene oxide obtained in step 210 is subjected to a decaneization reaction with a ruthenium oxygen coupling agent to form a second graphene oxide having a decyloxyalkyl group. The second graphene oxide was purified via filtration. According to an embodiment of the present invention, in the decaneization step 220, the chemical formula of the oxirane coupling agent used is RSi[O(CH ₃ )] _a (CH ₃ ) _3-a , wherein R is C3-C18 The alkyl group is preferably a C6-C10 alkyl group, most preferably a C8 alkyl group. And a is an integer from 0 to 3, preferably an integer from 1 to 3. According to an embodiment of the present invention, the above-mentioned oxime coupling agent has a molecular weight of from 102 to 360, most preferably from 144 to 276.

In accordance with an embodiment of the present invention, in the decaneization step 220, the oxime coupling agent is mixed with the first graphene oxide by ultrasonic vibration. The oscillating time can be from 0.5 hours to 5 hours, and the optimal oscillating time is from 2 hours to 4 hours.

In accordance with another embodiment of the present invention, in the decaneization step 220, the oxime coupling agent is reacted with the first graphene oxide using a high temperature agitation reflux reaction. The reaction temperature can be from 110 ° C to 150 ° C, and the optimum reaction temperature is from 120 ° C to 140 ° C. The reaction time can be from 12 hours to 36 hours, and the optimum reaction time is from 20 hours to 30 hours.

In the reduction step 230 of FIG. 2, the second graphene oxide obtained in step 230 is subjected to a reduction reaction with a reducing agent to cause an oxygen-containing group in the second graphene oxide which is not reacted with the oxirane coupling agent. And reduced to a carbon-carbon double bond (C=C) to form a decylated graphene having a decyloxyalkyl group. The decylated graphene was purified by filtration. According to an embodiment of the invention, in the reduction step 230, the reducing agent used is hydrazine (N ₂ H ₄ ).

After preparing the decadiene graphene (step 110), the tannin composite material can be directly prepared, and the manufacturing steps of the tannin composite material are referred to FIG. In step 120 of Figure 1, the decadiene graphene obtained in step 110 is dispersed in a silicone component to form a silicone dispersion containing decylated graphene.

Since the decylalkyl group of the decylated graphene has high compatibility with the tannin component, the interface energy barrier between the graphene and the tannin component is reduced, and the above-mentioned oxoalkyl group can reduce the attraction between the graphene. Van der Waal interaction. Therefore, the decylated graphene can be uniformly dispersed in the silicone component without any agglomeration. Furthermore, since the decyloxyalkylene of the decylated graphene has a comb-like steric structure, the dispersed decylated graphene can be interlaced to form a network structure, thereby strengthening the mechanical strength of the enamel composite.

In step 120, the main component of the tannin component used is polydimethylsiloxane, and its chemical structural formula may be H ₂ CCHSi(CH ₃ ) ₂ O[SiO(CH ₃ ) ₂ ] _n Si ( CH ₃ ) ₂ CHCH ₂ , where n is an integer from 50 to 500, and its viscosity is between 2500 mPa‧s and 4000 mPa‧s.

In step 130 of Figure 1, the silicone dispersion obtained in step 120 is allowed to cure naturally at room temperature to form a silicone composite. According to an embodiment of the present invention, in step 130, a hardener is added to the silicone dispersion to form a curing reaction solution. Then, the curing reaction liquid is injected into a mold to be heated and solidified to form a silicone composite material. The heating temperature is from 100 ° C to 150 ° C, preferably from 110 ° C to 130 ° C. According to an embodiment of the invention, the heating time is from 1 to 2 hours. The main component of the hardener used is a oxane coupling agent containing a platinum catalyst. The chemical structure of the above decane coupling agent is R'SiO(CH ₃ ) ₂ [SiO(CH ₃ ) ₂ ] _k [SiO(CH ₃ )H] _m SiR'. Wherein R' is methyl (CH ₃ ) or hydrogen (H), k is an integer from 1 to 30, and m is an integer from 1 to 30. The volume ratio of the silicone component to the hardener is 10:1.

Silicone composite composition

A silicone composite produced by the method of the present invention comprising a cured silicone substrate and a decylated graphene having a phosphonyl group. The use of the decylalkylene of the decylated graphene helps to disperse the decanolated graphene in the cured silicone substrate and interlace with the other decylated graphene oxyalkylene groups to form a network structure. According to an embodiment of the present invention, the content of the decadiene graphene in the silicone composite is from 0.5 wt% to 5 wt%.

The test method for the silicone composite material is provided below, wherein the measurement item of the silicone rubber composite material comprises a tensile mechanical strength test. The mechanical strength of the silicone composite was measured by the standard ASTM D638 and the tensile strength was measured using a Hung Ta microcurrent tensile tester.

Preparation and mechanical strength determination of tannin composite

Using the above-described manufacturing method, the decylated graphene having a C8 alkyl group is mixed with a silicone component to prepare a decylated graphene concentration of 0.5 wt%, 0.75 wt%, 1 wt%, 2 wt%, and 5 wt%, respectively. Silicone dispersion. Then, in the above-mentioned different decadiene graphene concentration of the tannin dispersion, a hardener is separately added to prepare a curing reaction liquid having different concentrations of the decadiene graphene, wherein the volume ratio of the silicone component to the hardener is 10:1.

A curing reaction solution having different concentrations of decaneated graphene is injected into a mold and heat-cured at a temperature ranging from 110 ° C to 130 ° C to form a silicone composite material having different decaneated graphene contents.

The mechanical strength of the silicone composite with different decaneated graphene content was compared with the silicone composite containing no decaneated graphene. The results are shown in Table 1 and Figure 3.

Table 1: Determination of mechanical strength of tannin composites

From the results of Table 1, it is known that the mechanical strength of the silicone composite containing decylated graphene is remarkably improved, and the mechanical strength increase rate is 1.3 times or more of that of the control group. When the undecylated graphene is incorporated, there is only a slight increase in the mechanical strength of the silicone composite.

In addition, if only the effect of the content of the decaneated graphene on the mechanical strength of the silicone composite is compared, the silicone composite has a better mechanical strength when the content of the decylated graphene is from 0.75 wt% to 2 wt%. Among them, when the content of decylated graphene is 1 wt%, the tannin composite has the best mechanical strength performance.

According to the results of the embodiments of the present invention, the decylated graphene can be uniformly dispersed in the silicone composite due to the characteristics of the decylated graphene. In addition, silicone rubber composites containing decaneated graphene have better mechanical strength to substantially improve the natural limitations of silicone. For the problems faced by conventional silicone materials, the silicone composite materials provided by the embodiments of the present invention provide a better solution and can be directly applied to a variety of high value-added industries.

The preferred embodiment of the invention has been disclosed above. However, the above-described manufacturing methods are not limited to the embodiments of the present invention, and various modifications and changes can be made without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be defined by the scope of the appended claims.

110, 120, 130. . . step

210, 220, 230. . . step

1 is a flow chart of a method for manufacturing a silicone composite material according to an embodiment of the present invention.

2 is a flow chart of a method for producing a decylated graphene according to an embodiment of the present invention.

Figure 3 is a mechanical strength line diagram of a silicone composite, in which the horizontal axis is graphene content (wt%) and the vertical axis is tensile strength (MPa), containing decaneated graphene (■), containing undecylated Graphene raw material (●).

110, 120, 130. . . step

Claims (19)

A method for producing a silicone composite material comprising the steps of: alkylating a graphene to form a decylated graphene having a decyloxyalkyl branch; dispersing the decylated graphene in a silicone component to form a a silicone dispersion of decylated graphene; and curing the silicone dispersion to form the silicone composite. The method for producing a silicone composite according to claim 1, wherein the curing the silicone dispersion comprises: adding a hardener to the silicone dispersion to form a curing reaction solution; and injecting the curing reaction solution into a mold. The medium is heat cured to form the silicone composite. The method for producing a silicone composite according to claim 2, wherein the temperature of the curing reaction solution is from 100 ° C to 150 ° C by heating. The method for producing a silicone composite according to claim 3, wherein the temperature of the curing reaction solution is from 110 ° C to 130 ° C. The method for producing a silicone composite according to claim 1, wherein the method for producing the decylated graphene comprises: breaking a carbon-carbon double bond (C=C) in the graphene under the action of an oxidizing agent and a strong acid, Forming a first graphene oxide having an oxygen-containing group; mixing and reacting an anthracene oxygen coupling agent with the first graphene oxide to form a second graphene oxide having a phosphonium alkyl group; The oxygen-containing group in the second graphene oxide which is not reacted with the oxime coupling agent is reduced to a carbon-carbon double bond (C=C) by the action of a reducing agent to form the decane having a decyloxy group. Graphene. The method for producing a silicone composite according to claim 5, wherein the oxidizing agent is potassium permanganate (KMnO ₄ ) and sodium nitrite (NaNO ₂ ), the strong acid is sulfuric acid (H ₂ SO ₄ ), and the reducing agent Contains hydrazine (N ₂ H ₄ ). The method for producing a silicone composite according to claim 5, wherein the oxygen-containing group is at least one selected from the group consisting of a hydroxyl group, an epoxy group, a carbonyl group, and a carboxylic acid group. The method for producing a silicone composite according to claim 5, wherein the oxime coupling agent has the following chemical structural formula: RSi[O(CH ₃ )] _a (CH ₃ ) _3-a wherein R is a C3-C18 alkane Base; and a is an integer from 0 to 3. The method for producing a silicone composite according to claim 5, wherein R of the anthracene coupling agent is a C6-C10 alkyl group. The method for producing a silicone composite according to claim 5, wherein the helium oxygen coupling agent is mixed with the first graphene oxide and reacted by an ultrasonic vibration method. The method for producing a silicone composite according to claim 1, wherein the silicone component comprises polydimethyloxane having a chemical structural formula of H ₂ CCHSi(CH ₃ ) ₂ O[SiO(CH ₃ ) ₂ ] _n Si(CH ₃ ) ₂ CHCH ₂ , wherein n is an integer from 50 to 500. The method for producing a silicone composite according to claim 1, wherein the viscosity of the silicone component is between 2,500 mPa·s and 4,000 mPa·s. The method for producing a silicone composite according to claim 2, wherein the hardener comprises a oxane coupling agent containing a platinum catalyst, and the chemical structure of the decane coupling agent is R'SiO(CH ₃ ) ₂ [SiO( CH ₃ ) ₂ ] _k [SiO(CH ₃ )H] _m SiR', wherein R' is methyl (CH ₃ ) or hydrogen (H), k is an integer from 1 to 30, and m is an integer from 1 to 30 . The method for producing a silicone composite according to claim 2, wherein a volume ratio of the silicone component to the hardener is 10:1. The method for producing a silicone composite according to claim 1, wherein the nonoxyalkylene group of the decylated graphene has a comb-like solid structure. The method for producing a silicone composite according to claim 1, wherein the decylalkyl group of the decylated graphene dispersed in the silicone composite material is interlaced with each of the decylated graphene to form a network structure. A silicone composite material produced by the manufacturing method according to any one of claims 1 to 16, comprising: a cured silicone substrate; and a decylated graphene having a decyloxyalkylene Dispersing in the cured silicone substrate, and the alkyloxyalkyl groups between the respective alkylene graphenes are interlaced to form a network structure. The silicone composite according to claim 17, wherein the content of the decylated graphene is from 0.5 wt% to 5 wt%. The silicone composite according to claim 17, wherein the optimum content of the decylated graphene is from 0.75 wt% to 2 wt%.