Application Research on Dispersibility and Anti-corrosion Performance of Functionalized Graphene Oxide in Powder Coatings

Abstract: Graphene oxide (GO) whose surface is modified by γ-(2,3-glycidoxy)propyltriethoxysilane (KH560) is mixed with gallic acid-based epoxy resin (GEP) to form functionalized graphite oxide Olefin (FGO)
.

It can effectively improve the dispersion of GO, and then make it evenly dispersed in the powder coating
.
The anti-corrosion coating is successfully prepared by electrostatic spraying .

Use SEM, Fourier Infrared Spectroscopy (FTIR), salt spray test, impact resistance test, contact angle test, etc.
to characterize and test GO and coating performance .
Coating online coatingol.
com
.

The influence of the amount of KH560 on the dispersibility of THF and powder coatings was investigated; at the same time, the influence of the amount of KH-560 modified GO on the performance of the coating was also investigated
.

The results show that the coating prepared with KH560 functionalized GO has excellent anti-corrosion and mechanical properties
.

1 Introduction

Metals are widely used in people's lives, but they face the problem of corrosion.
According to related reports, corrosion brings serious losses to the national economy every year, and it also causes certain harm to the environment
.

Coating is one of the most effective protection methods and one of the most widely used anti-corrosion technology methods
.
Epoxy resin and polyester resin are one of the commonly used coating resins.
It has excellent performance and is widely used in anti-corrosion coatings
.

GO has a stable structure, excellent toughness, hardness and excellent decorability, and has huge application prospects in various fields
.

However, GO has both hydrophilic and hydrophobic properties, which makes it difficult to use
.
If it is used in powder coatings, it cannot be mixed with powders, which reduces the stability of the coatings, which in turn causes defects in the coatings, reduces the anti-corrosion performance of the coatings, and greatly reduces the feasibility of GO application
.

Therefore, modifying GO and improving its dispersion in powder coatings is very important for GO anticorrosive powder coatings
.
Zhou Nan and others used GEP as a graphene dispersant to successfully improve the dispersibility of graphene in organic solvents, and GEP can participate in the reaction, further improving the stability of the coating
.

Parhizkar et al.
modified GO with triaminopropyltrimethoxysilane (APTES).
The modification of GO with APTES not only has covalent bonding (amino group and GO), but also has silanol groups that undergo polycondensation reactions with meridian and shuttle groups, which improves GO The dispersibility in epoxy resin also improves the corrosion resistance
.

Zheng et al.
grafted urea-formaldehyde on the GO sheet by polymer condensation reaction, which improved its dispersibility and corrosion resistance in epoxy resin
.

Ramezanzadeh et al.
successfully modified GO with p-phenylenediamine through covalent bonds, and obtained epoxy resin anticorrosive coatings with good miscibility, which greatly improved the anticorrosive performance
.

This paper not only uses GO as a special function filler, but also uses FGO as a reaction object
.
The combination of the KH56O modification and GEP effectively inhibits the secondary stacking of graphene, and then powder FGO is prepared, and FGO is added to the powder coating, thereby obtaining a graphene anticorrosive powder coating with excellent dispersibility and anticorrosive performance
.

2.
Experimental part

2.

KH-560, acetic acid, gallic acid, epichlorohydrin, NaOH, NaCI, tetrabutylammonium bromide, tetrahydrofuran (THF): analytical grade, Sinopharm Chemical Reagent Co.
, Ltd.
;

Epoxy resin E-12: Industrial grade, Hunan Yueyang Chemical Plant;

Barium sulfate: industrial grade, Changzhou Fengshuo Chemical Co.

Qin white powder: industrial grade, Shanghai DuPont Chemical (International) Co.
, Ltd.
;

GO: Industrial, Materials Technology Co.
, Ltd.
Element Six
.

2.
2 Experimental process

2.
2.
1 Preparation of FGO

After 5g GO (GO was stripped by ultrasound for 6 hours to form a few layers of GO), 500g THF was dispersed at high speed for 10 minutes, and then placed in an ultrasonic device
.

KH560 (1.
%, 2.
%, 3.
%, 4.
%, 5.
%, relative to the mass of GO) dosage, 0.
5g acetic acid was added to a four-necked flask, 40 ℃ water bath reaction 8h, add 15g GEP (GEP For the preparation details, please refer to Reference 1).
After stirring, use low-temperature cooling and drying to obtain powdered FGO
.

2.
2.
2 Preparation of GO anticorrosive powder coating and coating

Table 1 shows the basic formula of the powder coating.
The FGO powder prepared above is directly added to the powder coating and stirred evenly, and then sieved (200 mesh) to obtain the FGO anticorrosive powder coating
.

Using electrostatic spraying method, the powder is sprayed on the cold-rolled plate and cured at 200°C for 10 minutes to obtain the FGO anticorrosive powder coating.

2.

Measure the water contact angle of the coating with the PT-705-B contact angle measuring instrument of Dongguan Pusite Testing Equipment Co.
, Ltd.
;

Carizeiss SUPRA55 field emission scanning electron microscope was used to observe the composite material;

Use Q-FOG CCT-1100 salt spray test to test salt spray performance;

Use QCJ type coating film impact resistance tester to test coating performance;

Test coating performance according to HG/T 2006-2006
.

3.

3.
1 The influence of KH-560 dosage on GO dispersion

According to section 2.
2.
1, GO was modified with K-560, and the influence of KH-560 dosage on GO dispersion was investigated.
The results are shown in Figure 2
.

It can be seen from Figure 2 that when the dosage of KH560 is 0, the accumulation of GO is small and the dispersibility is better.
When the dosage is 4.
0%, the accumulation is the largest
.

，GO，
。KH560，GO，KH560，GOπ-π，
。

KH560，GO，，GO
。

3.
2 FG

GO、KH560-GO，3
。

3a3430cm-1,1740cm-1，1025cm-1-OH，C=OHC-O-C，1640cm-11410cm-1-(C=O）--COO-

b1035cm-1Si-O-C，GOKH560，a，1740cm-11410cm-1，GOKH560；

810cm-1，1130cm-1Si-O-Si，KH560；

915cm-1，KH560
。c12l0cm-1C-N，1540~1570cm-1N-H，915cm-1，
。

3.
3 FG

2.

4,FGOKH560
。KH560，GO，GO，
。

，
。，GO，GOπ-π，GO，，
。

，，GO，2E，，，，，
。

KH5603.
0％，
。3.
0%KH-560GO
。

3.
4 FGO

1.
2.
2，l，FGO
。HG/T 2006-2006，2
。

2，FGO，
。

GO，，、
。

KH560，GO，；

GO，，，GO，
。

，，、
。

3.
5 FG 

25，FGO，，

，，GOGO，，；

GO，GO，，GO，，
。

GO，GO，，，，
。

25，FGO7.
5％，
。

4、

(1）KH560GO，GO，KH5603.
0 wt.
％；FG7.
5％；，，
。

(2）GO，

(3）GO，

(4) When the amount of FGO is 7.
5%, the coating performance is the best
.

Source: Jiangsu Huaguang Powder Co.
, Ltd.