阅读说明：本技术 一种通过开环加成反应在碳纤维表面接枝纳米二氧化硅的方法 (A method of by opening in carbon fiber surface engrafted nanometer silica ) 是由 马丽春 宋国君 朱莹莹 李晓茹 石龙龙 王明业 冯培峰 于 2019-08-27 设计创作，主要内容包括：一种通过开环加成反应在碳纤维表面接枝纳米二氧化硅的方法,它一种碳纤维表面改性的方法。本发明的目的是要解决现有碳纤维的热氧化性及界面强度低的问题。方法：一、碳纤维抽提处理；二、碳纤维氧化处理；三、碳纤维接枝KH550；四、改性纳米二氧化硅的制备；五、开环加成反应接枝纳米二氧化硅,得到表面接枝纳米SiO<Sub>2</Sub>的碳纤维。本发明使用偶联剂之间的交叉反应法,在碳纤维和纳米SiO<Sub>2</Sub>上分别接枝不同种类且可以互相反应的偶联剂,利用偶联剂反应所形成的化学键,将碳纤维和纳米SiO<Sub>2</Sub>有机的结合在一起,消除之前单纯偶联剂接枝的缺点与不足,更好的提高碳纤维与树脂基的界面性能。本发明适用于碳纤维表面改性。(A method of by opening in carbon fiber surface engrafted nanometer silica, a kind of its method of carbon fiber surface modification.The invention aims to solve the problems, such as that the thermal oxidation of existing carbon fiber and boundary strength are low.Method: one, carbon fiber extracting is handled；Two, carbon fiber oxidation processes；Three, carbon fiber is grafted KH550；Four, the preparation of modified manometer silicon dioxide；Five, opening engrafted nanometer silica obtains surface grafting Nano-meter SiO_2 2 Carbon fiber.The present invention is using the cross reaction method between coupling agent, in carbon fiber and Nano-meter SiO_2 2 It is upper to be grafted variety classes respectively and chemical bond is formed by using coupling agent reaction, by carbon fiber and Nano-meter SiO_2 with the coupling agent of interreaction 2 It combines, it is the shortcomings that simple coupling agent grafting and insufficient before eliminating, preferably improve carbon fiber and resin-based interface performance.The present invention is suitable for carbon fiber surface modification.)

1. it is a kind of by opening carbon fiber surface engrafted nanometer silica method, it is characterised in that this method It is completed by the following steps:

One, carbon fiber extracting is handled: carbon fiber is placed in Soxhlet extractor, then is heated to reflux cleaning by cleaning agent of acetone, It takes out after carbon fiber that drying to constant weight for vacuum constant temperature again, obtains extracting treated carbon fiber；

Two, carbon fiber oxidation processes:

1., by AgNO₃And K₂S₂O₃It is dissolved into deionized water, obtains black mixed solution；

2., will extracting treated that carbon fiber is immersed in black mixed solution, reheating reaction to black mixed solution becomes Colourless transparent solution, then dried after carbon fiber is taken out, obtain the carbon fiber of oxidation processes；

Three, carbon fiber is grafted KH550:

Silane resin acceptor kh-550 and dehydrated alcohol are uniformly mixed, silane resin acceptor kh-550 ethanol solution is obtained；It will The carbon fiber of oxidation processes is immersed in silane resin acceptor kh-550 ethanol solution, then is condensed back under magnetic stirring anti- It answers, then is used washes of absolute alcohol 2~3 times after carbon fiber is taken out, then drying to constant weight in vacuum constant temperature drying box, obtains It is grafted the carbon fiber of KH550；

The volume ratio of silane resin acceptor kh-550 and dehydrated alcohol is 5:95 in step 3；

Four, the preparation of modified manometer silicon dioxide:

By SiO₂It is added in dehydrated alcohol, then carries out ultrasound, obtain uniform suspension；Silicon is added into uniform suspension Alkane coupling agent KH-560, obtains reaction solution；Reaction solution is transferred in oil bath pan, then carries out being condensed back under magnetic stirring anti- It answers, obtains reaction product；It is cleaning agent to reaction product eccentric cleaning using dehydrated alcohol, places into drying in constant temperature drying box, Obtain the modified silica of silane coupling agent KH-560；

SiO in uniform suspension described in step 4₂Mass fraction 4%~8%；

The mass fraction of silane coupling agent KH-560 is 1%~3% in reaction solution described in step 4；

Five, opening engrafted nanometer silica:

The modified silica of silane coupling agent KH-560 is dispersed in dehydrated alcohol first, ultrasound is then carried out, obtains silicon Alkane coupling agent KH-560 modified silica/dehydrated alcohol mixed liquor；The carbon fiber for being grafted KH550 is immersed in silane coupled In agent KH-560 modified silica/dehydrated alcohol mixed liquor, then condensing reflux reaction is carried out, after reaction, is cooled to Room temperature, then using dehydrated alcohol be cleaning agent to carbon fiber supersound washing, is finally putting into drying box that drying to constant weight, obtains surface Engrafted nanometer SiO₂Carbon fiber；

The quality of silane coupling agent KH-560 described in step 5 modified silica and the volume ratio of dehydrated alcohol are (1g ~3g): (30mL~90mL).

2. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that the time that cleaning is heated to reflux in step 1 is 40h~48h, and the temperature of vacuum constant temperature drying is 100 DEG C.

3. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that step 2 1. described in black mixed solution in AgNO₃Concentration be 0.01mol/L~0.02mol/L, K₂S₂O₃Concentration be 0.1mol/L~0.15mol/L；Step 2 2. described in heating reaction temperature be 65 DEG C~75 DEG C, do Dry temperature is 75 DEG C~85 DEG C, and drying time is 12h~14h.

4. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that the temperature that reaction is condensed back in step 3 is 70 DEG C, and the time for being condensed back reaction is 5h~7h, magnetic force The speed of stirring is 100r/min~300r/min, and the temperature of drying is 100 DEG C.

5. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that the temperature of condensing reflux described in step 4 is 100 DEG C, and the time of condensing reflux is 5h~7h, magnetic force The speed of stirring is 100r/min~300r/min, and the number of eccentric cleaning is 3 times~5 times, and the time of each eccentric cleaning is 10min~30min, the speed of each eccentric cleaning are 100r/min~300r/min, and drying temperature is 70 DEG C~90 DEG C, dry Time is 6h~8h.

6. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that SiO in uniform suspension described in step 4₂Mass fraction 6%；Reaction described in step 4 The mass fraction of silane coupling agent KH-560 is 2% in liquid.

7. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that ultrasonic time described in step 5 is 50min~60min, and ultrasonic power is 100W~300W.

8. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that the temperature of condensing reflux described in step 5 is 100 DEG C, and the time of condensing reflux is 3h~5h.

9. it is according to claim 1 it is a kind of by opening in the side of carbon fiber surface engrafted nanometer silica Method, it is characterised in that it using dehydrated alcohol is cleaning agent to carbon fiber supersound washing 5 times~6 times in step 5, each supersound washing Time be 50min~60min, the power of supersound washing is 100W~300W.

10. it is according to claim 1 it is a kind of by opening in carbon fiber surface engrafted nanometer silica Method, it is characterised in that drying temperature described in step 5 is 100 DEG C.

Technical field

The present invention relates to a kind of methods of carbon fiber surface modification.

Background technique

Nowadays the industry of most rich and powerful the Republic of China, surely belongs to materials industry.Basis of the material as all industries is promoting its people Economic level and aspect of improving the overall national strength have irreplaceable important function.It is fine compared to the metal material of comparative maturity Dimension resinous material has the characteristics that strong intensity height, hardness, light weight, density are small, corrosion-resistant and antifatigue.Extensive utilization to boat The high-precision pointed collar domain such as sky, space flight, war industry, automobile, with gradually development in recent years, fiber reinforced resinous material is also gradually applied In our daily life.

Usually there are many defects in the surface of carbon fiber, by being modified processing to carbon fiber surface, allow its surface Smooth degree decline increases its specific surface area, or by chemical method, its surface is allowed to increase more active groups.To The characteristics of making it preferably play the original high intensity of carbon fiber, high rigidity in conjunction with basis material, play its excellent mechanical property Energy.Currently, the carbon fiber surface modification method used both at home and abroad mainly includes chemical oxidation, coupling agent coating, sol-gel Method, chemical graft process, " Grafting-to " technology etc..

Carbon fiber is because the advantages of its high-strength light, is industrially widely used in high tip industry, but its poor heat Oxidisability and lower bound surface intensity limit carbon fibre composite in the development of aerospace field.

Summary of the invention

The invention aims to solve the problems, such as that the thermal oxidation of existing carbon fiber and boundary strength are low, and provide one kind By opening carbon fiber surface engrafted nanometer silica method.

The present invention it is a kind of by opening in the method for carbon fiber surface engrafted nanometer silica, be by following What step was completed:

One, carbon fiber extracting is handled: carbon fiber being placed in Soxhlet extractor, then is heated to reflux clearly by cleaning agent of acetone It washes, takes out after carbon fiber that drying to constant weight for vacuum constant temperature again, obtain extracting treated carbon fiber；

Two, carbon fiber oxidation processes:

1., by AgNO₃And K₂S₂O₃It is dissolved into deionized water, obtains black mixed solution；

2., will extracting treated that carbon fiber is immersed in black mixed solution, reheat reaction to black mixed solution Become colorless clear solution, then dries after carbon fiber is taken out, and obtains the carbon fiber of oxidation processes；

Three, carbon fiber is grafted KH550:

Silane resin acceptor kh-550 and dehydrated alcohol are uniformly mixed, it is molten to obtain silane resin acceptor kh-550 dehydrated alcohol Liquid；The carbon fiber of oxidation processes is immersed in silane resin acceptor kh-550 ethanol solution, then is condensed under magnetic stirring Back flow reaction, then used washes of absolute alcohol 2~3 times after carbon fiber is taken out, then be dried to perseverance in vacuum constant temperature drying box Weight obtains the carbon fiber of grafting KH550；

The volume ratio of silane resin acceptor kh-550 and dehydrated alcohol is 5:95 in step 3；

Four, the preparation of modified manometer silicon dioxide:

By SiO₂It is added in dehydrated alcohol, then carries out ultrasound, obtain uniform suspension；Add into uniform suspension Enter silane coupling agent KH-560, obtains reaction solution；Reaction solution is transferred in oil bath pan, then is condensed back under magnetic stirring Stream reaction, obtains reaction product；It is cleaning agent to reaction product eccentric cleaning using dehydrated alcohol, places into constant temperature drying box and do It is dry, obtain the modified silica of silane coupling agent KH-560；

SiO in uniform suspension described in step 4₂Mass fraction 4%~8%；

The mass fraction of silane coupling agent KH-560 is 1%~3% in reaction solution described in step 4；

Five, opening engrafted nanometer silica:

The modified silica of silane coupling agent KH-560 is dispersed in dehydrated alcohol first, ultrasound is then carried out, obtains Silica/dehydrated alcohol the mixed liquor modified to silane coupling agent KH-560；The carbon fiber for being grafted KH550 is immersed in silane In coupling agent KH-560 modified silica/dehydrated alcohol mixed liquor, then condensing reflux reaction is carried out, it is after reaction, cold But to room temperature, then using dehydrated alcohol it is cleaning agent to carbon fiber supersound washing, is finally putting into drying box that drying to constant weight, obtains Surface grafting Nano-meter SiO_2₂Carbon fiber；

The quality of silane coupling agent KH-560 described in step 5 modified silica and the volume ratio of dehydrated alcohol For (1g~3g): (30mL~90mL).

The principle of the present invention:

The present invention uses silane coupling agent as intermediate bridge, completes Nano-meter SiO_2₂Graft modification to carbon fiber.It uses Silane coupling agent KH550 and KH560 are linked together by opening, not only make Nano-meter SiO_2₂In conjunction with carbon fiber It is closer, while the amino of a molecule can increase Nano-meter SiO_2 with the epoxy group addition of two molecules₂Grafting efficiency.

Advantages of the present invention:

Simple coupling agent engrafted nanometer SiO₂It is limited to the modified effect of carbon fiber mechanical property, sol-gel method High-temperature process is larger to the performance damage of carbon fiber itself, directly adds Nano-meter SiO_2 in the base₂Easily reunite, be difficult to disperse, The present invention then uses the cross reaction method between coupling agent, in carbon fiber and Nano-meter SiO_2₂It is upper to be grafted variety classes and be mutual respectively The coupling agent of phase reaction is formed by chemical bond using coupling agent reaction, by carbon fiber and Nano-meter SiO_2₂Organically combine one The shortcomings that rising, eliminating before coupling agent grafting merely and insufficient, better raising carbon fiber and resin-based interface performance, enhancing The mechanical property of composite material.

The present invention is suitable for carbon fiber surface modification.

Detailed description of the invention

Fig. 1 is the XPS map of extracting treated carbon fiber obtained in one step 1 of embodiment；

Fig. 2 is surface grafting Nano-meter SiO_2 obtained in one step 5 of embodiment₂Carbon fiber XPS map；

Fig. 3 is untreated carbon fiber surface topography map；

Fig. 4 is surface grafting Nano-meter SiO_2 obtained in one step 5 of embodiment₂Carbon fiber surface topography map；

Fig. 5 is interface shear strength histogram, in figure 1 be untreated carbon fiber interface shear strength, 2 be embodiment The interface shear strength of extracting treated carbon fiber obtained in one step 1,3 oxygen 2. obtained for one step 2 of embodiment Change the interface shear strength of the carbon fiber of processing, the 4 surface grafting Nano-meter SiO_2s obtained for one step 5 of embodiment₂Carbon fiber Interface shear strength.

Specific embodiment