阅读说明：本技术 一种橡胶用石墨烯复合助剂及其制备方法 (Graphene composite additive for rubber and preparation method thereof ) 是由 陶磊 王煜玮 于 2020-07-13 设计创作，主要内容包括：本发明公开一种橡胶用石墨烯复合助剂材料的制备方法,主要步骤包括氧化石墨烯插层改性功能化过程,纳米氧化锌颗粒制备及改性过程以及二者的插层均匀分散步骤,所得产品中石墨烯与纳米氧化锌二者相互穿插,最终得到均匀分散的纳米氧化锌石墨烯两相堆叠结构,应用过程中,二者相互促进对方在橡胶中的分散,同时纳米氧化锌的插层也避免了石墨烯在机械混炼时容易发生二次堆叠的现象,用做橡胶生产中的活化剂可以优化硫化过程,同时可以降低普通氧化锌的用量,石墨烯经改性后极大地增强了与橡胶的结合相容性,提高了硫化胶的交联密度,最大限度地提高了材料的使用性能,该制备方法简单高效,节能,适合大规模生产。(The invention discloses a preparation method of a graphene composite auxiliary material for rubber, which mainly comprises a graphene oxide intercalation modification functionalization process, a nano zinc oxide particle preparation and modification process and an intercalation uniform dispersion step of the nano zinc oxide particle and the nano zinc oxide, wherein the graphene and the nano zinc oxide are mutually interpenetrated in an obtained product, and a uniformly dispersed nano zinc oxide graphene two-phase stacked structure is finally obtained, in the application process, the graphene and the nano zinc oxide mutually promote the dispersion of the other side in rubber, meanwhile, the intercalation of the nano zinc oxide also avoids the phenomenon that the graphene is easy to be secondarily stacked during mechanical mixing, the graphene composite auxiliary material can be used as an activating agent in rubber production to optimize a vulcanization process, and simultaneously reduce the using amount of common zinc oxide, the graphene is greatly enhanced in combination compatibility with the rubber after being modified, the crosslinking density of vulcanized rubber is improved, and the service performance of the material is furthest improved, the preparation method is simple, efficient, energy-saving and suitable for large-scale production.)

1. The preparation method of the graphene composite additive for rubber is characterized by comprising the following steps:

a. preparing an intercalation modified functional product of graphene oxide, sequentially adding a graphene oxide filter cake, a dispersing agent, a graphene modifier and deionized water into a sand mill, uniformly dispersing by the sand mill, and then heating for reaction for 1 hour to obtain the graft modified graphene oxide aqueous dispersion.

b. And (b) adding a sodium hydroxide solution into the solution obtained in the step a to adjust the pH value to 8-11, then adding a zinc-containing source solution, stirring for 10 minutes, reacting for 1 hour at a set temperature, continuously titrating by using 4mol/L NaOH as an alkali source in the process, adding a surfactant, adding a modified coupling agent after reflux reaction for 1 hour, and continuing to react for 1 hour.

c. And c, filtering and washing the product obtained in the step b, drying the product in an oven at the temperature of 80 ℃ for 24 hours, grinding the product to obtain a precursor compound, and finally calcining the precursor compound in a vacuum-pumping nitrogen-replacing box furnace at high temperature for 2 hours to obtain the graphene auxiliary agent composite material for the rubber.

2. A method of preparing a composite material according to claim 1, wherein: in the step a, the graphene modifier is polyvinyl alcohol, octadecylamine or one of ethylenediamine and hexamethylenetetramine.

3. A method of preparing a composite material according to claim 1, wherein: in the step a, the dispersing agent is one or more of sodium polyacrylate, sodium dodecyl benzene sulfonate, dodecyl trimethyl ammonium bromide and dodecyl sodium sulfonate.

4. A method of preparing a composite material according to claim 1, wherein: in the step b, the zinc source is one of zinc chloride, zinc sulfate heptahydrate, zinc nitrate and zinc acetate.

5. A method of preparing a composite material according to claim 1, wherein: the mass ratio of zinc oxide to graphene in the zinc source is 95: 5-1: 1.

6. A method of preparing a composite material according to claim 1, wherein: the surfactant in the step b is an ionic surfactant or a non-ionic surfactant, and preferably one or more of sodium dodecyl benzene sulfonate, Brij700, polyethylene glycol PEG4000 and polyvinylpyrrolidone are selected.

7. A method of preparing a composite material according to claim 1, wherein: preferably, the ionic surfactant is selected from one of sodium dodecyl sulfonate and sodium dodecyl benzene sulfonate cetyl trimethyl ammonium bromide.

8. A method of preparing a composite material according to claim 1, wherein: in the step b, the modified coupling agent is one of Si69, KH550, KH560 or KH 570.

9. A method of preparing a composite material according to claim 1, wherein: in step b the temperature was set at 60 ℃.

10. A method of preparing a composite material according to claim 1, wherein: the high-temperature calcination temperature is 300-600 ℃.

Technical Field

The invention relates to a preparation method of an auxiliary agent for rubber, in particular to a preparation method of a modified nano zinc oxide intercalation modified functionalized graphene nano composite material.

Background

Graphene is a monolayer of carbon atoms passing through sp²A novel carbon material with a two-dimensional honeycomb lattice structure formed by hybridization and close packing has ultrahigh mechanical property, high thermal conductivity, high anisotropy, high electron mobility, high light transmittance, high specific surface area, high barrier property and the like. The single-layer graphite is considered to be the thinnest and strongest material in the universe so far, has extremely high physical and mechanical properties, and is widely concerned in the field of rubber reinforcement in recent two years.

The preparation cost of the single-layer graphene is high due to the fact that the existing large-scale preparation process of the graphene is not mature, the cost can be greatly increased when the graphene is applied to industrial products, and the graphene cannot be widely applied. The graphene microchip is an ultrathin graphene laminated accumulation body with more than 10 layers and a thickness of 5-100 nanometers, maintains a planar carbon six-membered ring conjugated crystal structure of graphene, and has excellent mechanical strength, electric conduction and heat conduction properties, and good lubricating, high temperature resistant and corrosion resistant properties. Compared with common graphite, the thickness of the graphene nanoplatelets is in the nanoscale range, but the radial width of the graphene nanoplatelets can reach tens of microns to tens of microns, the graphene nanoplatelets have an ultra-large shape ratio, and the graphene nanoplatelets have large-scale production capacity and high product cost performance at home at present. However, strong van der waals force and pi-pi interaction between graphene layers enable the graphene to be tightly stacked and not easy to peel off, which increases difficulty in the research of preparing rubber/graphene nanocomposites by means of a traditional mechanical blending method. And the extremely stable chemical structure of the graphene enables the graphene to be almost insoluble in all low-boiling-point organic solvents, which provides a barrier for preparing the rubber-based graphene nanocomposite by using a solution compounding method.

The rubber is lack of crystallization capacity and small in intermolecular force, so that the mechanical property, the electrical property and the like of the rubber can meet the application requirement of a polymer material after being enhanced, the unique structure of the graphene endows the graphene with excellent physicochemical properties, and the graphene has high strength, high heat conductivity, high conductivity and high specific surface area, and zinc oxide is an active agent of natural latex. It is the most important inorganic activator in rubber industry, and the addition of the rubber material can not only accelerate the vulcanization speed, but also improve the crosslinking degree. It has activating effect on thiazole, sulfenamide, guanidine, and thiuram accelerators. The zinc oxide can be widely used for various rubber products, has the functions of reinforcement and reinforcement, and can improve the heat conduction performance of rubber. After the graphene and the zinc oxide are combined and used as a vulcanization activator to be added into rubber, the physical and mechanical properties, the electric conductivity, the thermal properties and the gas barrier properties of the rubber can be obviously improved, particularly the tensile strength and the elongation at break of the rubber are obviously improved, and the using amount of the zinc oxide in a rubber formula can be effectively reduced, so that the graphene-zinc oxide composite material for the rubber has high economic value, and simultaneously meets the current requirements of environmental protection.

The nano zinc oxide serving as inorganic powder is difficult to add into a polymer, has small particle size, high surface energy, hydrophilicity and oleophobicity, is in a thermodynamic unstable state, is easy to agglomerate, and is difficult to realize effective uniform dispersion, so that the nano zinc oxide is subjected to hydrophobic treatment, and the nano zinc oxide has a vital effect on improving the compatibility and the dispersibility with the polymer.

Disclosure of Invention

The invention aims to provide a preparation method of a graphene composite additive for rubber, which comprises the steps of firstly utilizing the interaction of a surface functional group of graphene oxide and a modifier to form special graphene which is beneficial to rubber, expanding interlayer spacing, then depositing nano zinc oxide particles on the surface of a graphene sheet layer through the liquid deposition of nano zinc oxide to form intercalation, so that the graphene and the graphene form a mutual entanglement and interpenetration structure, thereby being beneficial to the effective dispersion of the graphene and the graphene, forming effective steric hindrance between the graphene sheet layers due to the deposition of the surface, and avoiding the wrinkle of the graphene caused by too large specific surface area in the rubber processing process, thereby obtaining a rubber vulcanized material with more excellent performance.

The technical scheme of the invention comprises the following steps:

1. the preparation method of the graphene composite additive for rubber is characterized by comprising the following steps:

a. preparing an intercalation modified functional product of graphene oxide, sequentially adding a graphene oxide filter cake, a dispersing agent, a graphene modifier and deionized water into a sand mill, uniformly dispersing by the sand mill, and then heating for reaction for 1 hour to obtain the graft modified graphene oxide aqueous dispersion.

b. And (b) adding a sodium hydroxide solution into the solution obtained in the step a to adjust the pH value to 8-11, then adding a zinc-containing source solution, stirring for 10 minutes, reacting for 1 hour at a set temperature, continuously titrating by using 4mol/L NaOH as an alkali source in the process, adding a surfactant, adding a modified coupling agent after reflux reaction for 1 hour, and continuing to react for 1 hour.

c. And c, filtering and washing the product obtained in the step b, drying the product in an oven at the temperature of 80 ℃ for 24 hours, grinding the product to obtain a precursor compound, and finally calcining the precursor compound in a vacuum-pumping nitrogen-replacing box furnace at high temperature for 2 hours to obtain the graphene auxiliary agent composite material for the rubber.

2. A method of preparing a composite material according to claim 1, wherein: in the step a, the graphene modifier is polyvinyl alcohol, octadecylamine or one of ethylenediamine and hexamethylenetetramine.

3. A method of preparing a composite material according to claim 1, wherein: in the step a, the dispersing agent is one or more of sodium polyacrylate, sodium dodecyl benzene sulfonate, dodecyl trimethyl ammonium bromide and dodecyl sodium sulfonate.

4. A method of preparing a composite material according to claim 1, wherein: in the step b, the zinc source is one of zinc chloride, zinc sulfate heptahydrate, zinc nitrate and zinc acetate.

5. A method of preparing a composite material according to claim 1, wherein: the mass ratio of zinc oxide to graphene in the zinc source is 95: 5-1: 1.

6. A method of preparing a composite material according to claim 1, wherein: the surfactant in the step b is an ionic surfactant or a non-ionic surfactant, and preferably one or more of sodium dodecyl benzene sulfonate, Brij700, polyethylene glycol PEG4000 and polyvinylpyrrolidone are selected.

7. A method of preparing a composite material according to claim 1, wherein: preferably, the ionic surfactant is selected from one of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate and cetyl trimethyl ammonium bromide.

8. A method of preparing a composite material according to claim 1, wherein: in the step b, the modified coupling agent is one of Si69, KH550, KH560 or KH 570.

9. A method of preparing a composite material according to claim 1, wherein: the temperature in step b was set to 60 deg.C

10. A method of preparing a composite material according to claim 1, wherein: the high-temperature calcination temperature is 300-600 ℃.

Compared with the prior art, the invention has the advantages that:

(1) the special graphene composite additive for rubber can be obtained by the processing method, and the processing method can simultaneously improve the dispersion degree of graphene and nano zinc oxide in rubber and improve the compatibility of graphene and rubber.

(2) The common preparation conditions of nano zinc oxide preparation and graphene oxide reduction preparation are effectively utilized, the use amount of zinc oxide in rubber is reduced, waste caused by adding graphene during rubber banburying is reduced, energy consumption is greatly reduced, the compatibility of graphene and rubber is improved, the final use performance of vulcanized rubber is improved, and the method is suitable for industrial production and is green and efficient.

Detailed Description

The present invention will be described in further detail with reference to examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and those skilled in the art can make modifications and variations of the present invention without departing from the scope of the present invention.

TABLE 1 basic rubber experiment formulation

TABLE 2 basic Properties of the experimental formulations

Comparative example 1

According to a basic rubber formula shown in Table 1, 5 parts of common zinc oxide is added, and a natural rubber composite material is prepared by a conventional mixing method, wherein the preparation process comprises the following steps: adding natural rubber to the internal mixer → adding 2/3 filler → adding 1/3 filler → sweeping → adding small materials except for the vulcanizing agent → sweeping → discharging rubber, and adding a segment of rubber to the internal mixer after the segment is parked for more than 4 hours → adding the vulcanizing agent → sweeping → discharging rubber to obtain the rubber of comparative example 1.

Comparative example 2

(1) Dissolving 72 parts by weight of heptahydrate zinc sulfate in 100 parts by weight of deionized water to prepare a zinc sulfate solution, adding the zinc sulfate solution into a sodium hydroxide solution with the pH value of 9, stirring for 10 minutes, reacting at 60 ℃ for 1 hour, continuously titrating by using 31 parts by weight of 4mol/L NaOH as an alkali source in the process, adding 0.1 part by weight of polyethylene glycol PEG4000, adding 1 part by weight of KH550 after reflux reaction for 1 hour, and continuously reacting for 1 hour.

(2) And (2) filtering the product obtained in the step (1), washing with water, drying in an oven at 80 ℃ for 24 hours, grinding to obtain a precursor compound, and finally calcining the precursor compound in a vacuum-pumping nitrogen-replacing box furnace at the high temperature of 400 ℃ for 2 hours to obtain the active nano zinc oxide.

According to the basic rubber formula shown in Table 1, 2 parts of active nano zinc oxide prepared in the example is added, and the natural rubber composite material is prepared by a conventional mixing method, and the preparation process is the same as that of comparative example 1, and the rubber of comparative example 2 is obtained by mixing.