Application of graphene in waterborne coatings!

Modified water dispersed modified graphene with titanate coupling agent

According to the general method, the graphite is made of graphene oxide, and the titanate and hydrazine hydrate are added to the graphene oxide dispersion, and the reaction occurs under the water bath heating method, so that the graphene oxide is reduced and grafted with the titanate coupling agent molecule

Since the titanate coupling agent has surface modified graphene oxide and no longer produces agglomeration, the graphene water dispersion has high stability and can be stored for a long time, which is suitable for the preparation of composite materials and coating materials

Graphene blended with matrix resin composite waterborne coatings

1 Waterborne conductive coatings

Graphene/polyester resin composite waterborne conductive coating.

2 Graphene modified waterborne epoxy resin wear-resistant glass coating

Graphene-modified abrasion-resistant water-resistant glass coatings consist of two components, the first group is divided into matrix film-forming, and the second group is divided into curing agents

3 Graphene modified acrylate polymer cement waterproof coating

® Graphene oxide prepared by Hummers method is added to the acrylate polymer emulsion, added to the selected additive, added to the cement in proportion, stirred and dispersed, and made into a polymer cement waterproof coating

4 Graphene modified polyurethane resin composite waterborne coating

4.
1 Graphene/waterborne polyurethane nanocomposite emulsion

The vacuum dehydrated polyether polyol (N210) and TDI reaction prepared polyurethane prepolymer, added biserhydroxymethylpropionic acid into hydrophilic carboxyl groups, added triethylamine to neutralize the salt group, added graphene oxide aqueous solution, deionized water and ethylenediamine for emulsification reaction, distilled out acetone under reduced pressure, added vitamin C solution dropwise for in situ reduction reaction, to obtain a constant liter of quaternary ® graphene / waterborne polyurethane nanocomposite latex resin
.
HESION The latex resin can be applied to electrostatic protection, anti-corrosion coatings, architectural coatings and other fields, the present invention process is simple, environmentally friendly, suitable for large-scale production
.

4.
2 Graphene/TiO2 composite modified waterborne polyurethane antibacterial coating

As a kind of photocatalytic nanomaterial, nanoTiO2 has antibacterial sterilization effect, but its absorption rate for visible light is low, and nanoparticles tend to aggregate, which greatly reduces its sterilization effect
.
In the nano-TiO2 antibacterial coating, less than 5% of graphene is introduced, which significantly improves the absorption rate of the paint to visible light, and strengthens the photocatalytic activity of nano-TiO2 and the antibacterial and sterilization ability, so that the modified waterborne polyurethane has greatly improved
the comprehensive performance of antibacterial sterilization.
And has good surface properties, water resistance and mechanical properties
.

4.
3 Waterborne conductive coatings for graphene/polyurethane in situ polymerization

Graphene has more excellent conductivity and mechanical properties
than traditional carbon-based conductive fillers (carbon black, graphite, carbon nanotubes, carbon fibers, etc.
).

The constant liter pentameter uses ® dibasic amines to aminolate and modifies graphene, and then restores the conjugate conductive system of graphene by chemical reduction, and uses the waterborne polyurethane of the graphene surface to polymerize in situ with the waterborne polyurethane of the -NH and -NCO seals to obtain a constant liter pentathionic ® waterborne polyurethane conductive coating containing
graphene.

The conductive coating has the characteristics of radiation protection, anti-static, anti-corrosion, wear resistance, etc.
, and can be used for polymer materials, metal materials, textile material surfaces and other aspects
.

4.
4 Preparation of modified graphene/waterborne polyurethane nanocomposite coatings by sol-gel technology

The University of Science and Technology of China Xin Wang equals published their research paper in Surface & Coatings Technology in 2012: Preparation of modified graphene/waterborne polyurethane composite nanocoats using sol-gel technology, divided into 3 parts: (1) Preparation
of silane modified graphene nanofilms 。 Graphene oxide (GO) was prepared by Hummers method, and then the GO aqueous dispersion was chemically reduced to GNS with hydrazine, and then functionally modified with DCC (N, N'-dicyclohexylcarbonized diimide) and 3-aminopropyltriethoxysilane (APTES), dispersed with ultrasonic waves for 1 h, stirred at 70 °C for 24 h, and the functionally modified graphene nanofilm f-GNS
of APTES was obtained after post-treatment.

(2) Preparation
of waterborne polyurethane (WPU) with silane APTES capping.
The PU prepolymer was synthesized by mixing polyols with isophorone diisocyanate (IPDI), polypropylene oxide glycol, monocolyldiethylene glycol and trimethylolpropane, and then reacted with dihydroxymethylpropionic acid, and then added APTES to obtain a waterborne polyurethane (WPU) with APTES-capped ends, with a yield of 86.
3% and an average molecular weight of 28600 (GPC determination).

(3) Preparation of f-GNS/WPU nanocomposite coatings
by sol-gel technology.
With the help of ultrasonic, the f-GNS powder is dispersed in deionized water to make a suspension, and the APTES-terminated WPU is added to it and mixed together, and the pH value is adjusted with triethylamine to make an f-GNS/WPU nanocomposite coating
.

The structure of GO and f-GNS was characterized by 1H-NMR, FTIR, XPS, GPC, AFM, HRTEM, etc.
, and the molecular structure formula and reaction process shown in Figure 1 were basically verified, and the structure and composition
of f-GNS/WPU nanocomposite coating products were basically verified.
T1, T2, and T3 in the nanocomplex represent mono, two, and three substituted silane bonds, confirming a copolymerization reaction between apTES-terminated WPU and f-GNS adjacent siloxane molecules, forming a covalent bond
.

Fig.
1 Process of preparing f-GNS/WPU nanocomposite coatings by sol-gel method

Conclusion

1.
Graphene has unique properties, and the research and development boom has emerged in the world

Graphene is the "thinnest" crystalline material found in the world today, with a thickness of only 1 carbon atom, and is also one of the "strongest" materials, and has high electrical conductivity and high thermal conductivity
.
It is predicted that in aerospace, space exploration, marine development, national defense industry, national economy and other aspects of the application prospects, the research boom in the world, the domestic start is also good, the constant rise of the fifth power ® of rapid development
.

2.
Graphene has shown new prospects in the performance of modified coatings

Graphene has a very attractive potential prospect
in functional coatings such as conductive, anti-corrosion, flame retardant, thermal conductivity and high strength.

Graphene is compounded with various coating resins by physical blending, in situ polymerization and sol-gel technology; Or modified with coupling agents, or using in situ polymerization and other processes
.
These processes have proven feasible in modified waterborne coatings with significant
performance improvements.
Waterborne coatings are modified by graphene, and their performance is expected to be "higher", and its further development can be expected
.

3.
The pace of research and development of graphene modified coatings is just beginning, and it is necessary to correctly promote the development boom of graphene production and application, but it should be treated calmly
.

For production enterprises, whether the graphene production technology has reached the most advanced in the world, whether it meets the requirements of the clean and civilized production process, whether the cost is reasonable, there is a lot of technical work to be done
.
The application of graphene in coatings, there are many domestic research work and patent publications, the development momentum is better, but can not be said to be "into a good state"
.
Graphene and coating resin composite methods, additive selection, functional improvements, and the space for research and development of the five powers ® of Hengsheng are very large
.

The work and patents published in China for graphene modified waterborne coatings are mostly laboratory results, and to achieve practicality and industrialization, more investment is required, there is a lot of research and development work to be done, and there is still a long way to go
.