Research on hydroxyethyl ammonium O,O′-diphenyl dithiophosphate: Synthesis, characterization, surface activity and corrosion inhibition performance

Article abstract of DOI:10.1080/10426507.2019.1639703

Hydroxyethyl ammonium O,O′-diphenyl dithiophosphate (HADD) acting as a surfactant and corrosion inhibitor was successfully synthesized and characterized by FT-IR, ¹H NMR and single crystal X-ray diffraction. Meanwhile, the inhibition effect of HADD on Q235 steel (Q235s) corrosion in H₂SO₄ solution was studied by weight loss and potentiodynamic polarization measurements. HADD turned out to be an effective corrosion inhibitor and the inhibition efficiency increased with HADD concentration increasing, and significantly decreased with increasing both temperature and H₂SO₄ concentration. Potentiodynamic polarization measurements indicated that HADD was a mixed-type inhibitor.

Full text of DOI:10.1080/10426507.2019.1639703

Phosphorus, Sulfur, and Silicon and the Related Elements
ISSN: 1042-6507 (Print) 1563-5325 (Online) Journal homepage: https://www.tandfonline.com/loi/gpss20
Research on hydroxyethyl ammonium
O,O′-diphenyl dithiophosphate: Synthesis,
characterization, surface activity and corrosion
inhibition performance
Chuan Lai, Bin Xie & Xiaogang Guo
To cite this article: Chuan Lai, Bin Xie & Xiaogang Guo (2019): Research on hydroxyethyl
ammonium O,O′-diphenyl dithiophosphate: Synthesis, characterization, surface activity and
corrosion inhibition performance, Phosphorus, Sulfur, and Silicon and the Related Elements, DOI:
10.1080/10426507.2019.1639703
To link to this article: https://doi.org/10.1080/10426507.2019.1639703
View supplementary material
Published online: 10 Jul 2019.
Submit your article to this journal
Article views: 16
View Crossmark data
Full Terms & Conditions of access and use can be found at
https://www.tandfonline.com/action/journalInformation?journalCode=gpss20

PHOSPHORUS, SULFUR, AND SILICON AND THE RELATED ELEMENTS
https://doi.org/10.1080/10426507.2019.1639703
Research on hydroxyethyl ammonium O,O0-diphenyl dithiophosphate: Synthesis,
characterization, surface activity and corrosion inhibition performance
Chuan Laia,b , Bin Xieb, and Xiaogang Guoc
b
aSchool of Chemistry and Chemical Engineering, Sichuan University of Arts and Science, Dazhou, China; School of Materials Science and
c
Engineering, Sichuan University of Science and Engineering, Zigong, China; College of Chemistry and Chemical Engineering, Yangtze
Normal University, Chongqing, China
ABSTRACT
ARTICLE HISTORY
Hydroxyethyl ammonium O,O0-diphenyl dithiophosphate (HADD) acting as a surfactant and corrosion
inhibitor was successfully synthesized and characterized by FT-IR, 1H NMR and single crystal X-ray dif-
fraction. Meanwhile, the inhibition effect of HADD on Q235 steel (Q235s) corrosion in H2SO4 solution
was studied by weight loss and potentiodynamic polarization measurements. HADD turned out to be
an effective corrosion inhibitor and the inhibition efficiency increased with HADD concentration
increasing, and significantly decreased with increasing both temperature and H2SO4 concentration.
Potentiodynamic polarization measurements indicated that HADD was a mixed-type inhibitor.
Received 27 April 2019
Accepted 30 June 2019
KEYWORDS
Synthesis; characterization;
surface activity;
corrosion inhibition
GRAPHICAL ABSTRACT
Introduction
With the development of corrosion inhibitor research and
their applications in the field expanding, there are ample kinds
of corrosion inhibitors to consider, among which organic corro-
sion inhibitors have obvious advantages as effective corrosion
inhibitors. According to the relationships between inhibitors’
structures and their corrosion inhibition performance, O,O0-dia-
ryldithiophosphates and their derivatives are promising inhibi-
tors because of the N, P and S atoms within the structures. The
ionic compounds of O,O0-dialkyldithiophosphates diethyl
ammonium such as (O,O0-bis(p-methoxyphenyl)dithiophosphate
diethyl ammonium, O,O0-bis(4-chlorophenyl)dithiophosphate
diethyl ammonium) and covalent compounds of O,O0-diaryldi-
thiophosphates derivatives (S-benzyl-O,O0-bisphenyldithiophos-
phate, S-benzyl-O,O0-bisbenzyldithiophosphate, S-benzyl-O,O0-
bis(2-phenylethyl)dithiophosphate, S-benzyl-O,O0-bis(4-
methylphenyl)dithiophosphate, S-benzyl-O,O0-bis(2-naphthyl)
Corrosion has become a common problem all over the world;
wherever materials are used, there are corrosion problems
emerging, and leading to major economic loss.[1,2] Among
various types of corrosion, metal corrosion is extremely harm-
ful. Based on metal corrosion problem, using corrosion inhibi-
tors as an approach towards protection has become one of the
most widely used methods due to its advantages of economy,
high efficiency and universal scope.[3,4] Usually, corrosion
inhibitors are a one-component compound or multicomponent
chemicals that exist in the corrosive environment to prevent or
slow down metal corrosion process. Especially in offshore oil
and gas pipelines, chemical cleaning, petroleum products proc-
essing and other processes, more and more researchers have to
admit that using corrosion inhibitors for corrosion prevention
has become the most important method.[5–7]
CONTACT Chuan Lai
lc860801@163.com
School of Chemistry and Chemical Engineering, Sichuan University of Arts and Science, Dazhou, 635000, China.
Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/gpss.
Supplemental data for this article is available online at https://doi.org/10.1080/10426507.2019.1639703.
ß 2019 Taylor & Francis Group, LLC

2
C. LAI ET AL.
Table 1. Crystallographic data of HADD.
Compound
Hydroxyethyl ammonium O,O’-diphenyl dithiophosphate
Empirical formula
Formula mass
C14H18NO3PS2
343.38
Crystal system/Space group
Monoclinic, P21/c
13.5330 (13)
8.5681 (8)
14.4688 (14)
90
103.5440 (10)
90
a/Å
b/Å
c/Å
a/ꢂ
b/ꢂ
c/ꢂ
V/Å3
Z
1631.0 (3)
4
1.398
Dcalcd. (g cmꢀ3
l (mmꢀ1
)
)
0.432
Crystal size (mm)
Color/Shape
Temp (K)
0.19 ꢁ 0.17 ꢁ 0.16
Colorless, block
100
Theta range for collection
Reflections collected
Independent reflections
Data/restraints/parameters
Goodness of fit on F2
Final R indices [I > 2r(I)]
R indices (all data)
Largest difference peak/hole
aR1 ¼ RjjFoj ꢀ jFcjj/RjFoj, wR2 ¼ [Rw(Fo ꢀ Fc ) /Rw(Fo2)2]1/2
2.78–25.00
10886
2863
2863/4/190
1.026
R1 ¼ 0.0238
wR2 ¼ 0.0723
0.252, ꢀ0.296
2
2 2
.
dithiophosphate,
S-4-methylbenzyl-O,O0-bis(4-nitrophenyl) 1484.9 (s) and 1450.7 (m) cmꢀ1 represent C ¼ C bands and
dithiophosphate, S-4-methylbenzyl-O,O0-bis(4-tert-butylphe-
nyl)dithiophosphate, S-allyl-O,O0-bisphenyldithiophosphate,
S-allyl-O,O0-bisbenzyldithiophosphate and S-allyl-O,O0-bis(2-
phenylethyl) dithiophosphate) have been reported in our pre-
vious works as promising corrosion inhibitors.[4,6,8–11]
According to our previous reports,[10,11] the inhibition effi-
ciency for carbon steel in 0.5 M HCl with 100 mg Lꢀ1 con-
centration of O,O0-bis(p-methoxyphenyl)dithiophosphate
diethyl ammonium at 300 K is 87.63%, and the inhibition effi-
ciency for mild steel in 1.0 M HCl with 100 mg Lꢀ1 concen-
tration of S-allyl-O,O0-bisphenyl dithiophosphate, S-allyl-
O,O0-bisbenzyldithiophosphate and S-allyl-O,O0-bis(2-phenyl
ethyl) dithiophosphate at 303 K are 82.75%, 98.74 and 93.26,
respectively. Although these corrosion inhibitors showed good
anti-corrosion properties, both covalent and ionic O,O0-dia-
lkyldithiophosphates compounds all have low solubility in
water and acid solution. In order to properly regulate the
solubility of these inhibitors, hydroxyl groups are proposed to
be introduced into the target O,O0-dialkyldithiophosphates,
and the corresponding hydroxyethyl ammonium O,O0-diphe-
nyldithiophosphate (HADD) would be synthesized and char-
acterized. Meanwhile, the surface activity and corrosion
inhibition performance would be evaluated in detail.
those at 1207.5 (s), 1188.4 (s), 1162.4 (m), 1067.0 (m),
1004.8 (m) and 912.5 (s) cmꢀ1 are assigned to (P)-O-C and
(P-O-(C). At 879.0 (s), 770.4 (s) and 683.9 (s) cmꢀ1 The
peaks are attributable to S-C and PS2.
According to 1H NMR spectrum of HADD shown in
Figure S2, the two triplets at 2.86 and 3.58 ppm are assigned to
the CH2CH2 protons. Two singlet signals at 5.16 and 7.70 ppm
are attributed to OH and þNH3 protons, respectively.
Moreover, the phenyl proton signals exhibit one double of
doublets at 7.26 ppm and two multiplets in the regions of
7.05–7.08 and 7.29–7.34 ppm. These results confirm that the
structure of synthesized compound agrees with the structure of
hydroxyethyl ammonium O,O0-diphenyl dithiophosphate.
Crystal structure of HADD
A
colorless block single crystal with the size of
0.19 ꢁ 0.17 ꢁ 0.16 mm3 was selected to determine the struc-
ture of HADD by single crystal X-ray diffraction. All crystal
data were collected and summarized in Table 1. The crystal
molecule structure and the 2D layer structure connected by
the H-bonds of HADD shown in Figure 1 and Figure 2,
respectively. The selected bond distances and bond angles of
HADD listed in Table 2. Single-crystal X-ray analysis
revealed that HADD shows a 0D molecule structure and
crystallization in the monoclinic P21/c space group.
(CCDC 1908964)
Results and discussion
Characterization of HADD
The asymmetric unit is made up of the anionic group
O,O0-diphenyldithiophosphate ((PhO)2P(S)Sꢀ) and the cat-
ionic group hydroxyethyl ammonium (H3NþCH2 CH2OH,
Figure 1). The central P atom of the anionic group is coor-
dinated by two O atoms from two different deprotonated
phenol molecules and two S atoms. According to Table 2,
the bond length of P (1) - O (1) (1.6254 (10) Å) is longer
1
FT-IR and H NMR
The FT-IR spectrum of HADD was presented in Figure S1
(Supplemental Materials). The peak at 3365.1 (s) cmꢀ1 is
attributable to the different hydroxyl groups (-OH) present
in H2O, and cationic group ([H3NþCH2CH2OH]) and those
at 3008.0 (m) and 2937.1 (w) cmꢀ1 belong to ¼ C-H and
-CH2CH2-, respectively. Peaks at wavenumbers of 1587.6 (s), than the bond length of P (1) - O (2) (1.6163 (10) Å), and

PHOSPHORUS, SULFUR, AND SILICON AND THE RELATED ELEMENTS
3
Figure 3. H-bonds between the molecule strctures in HADD.
Figure 1. Crystal molecule structure of HADD.
Figure 4. Variations in surface tension with HADD concentrations in double dis-
tilled water at 30 ꢂC.
Figure 2. 2D layer structure of HADD.
around P atom with two S atoms and two O atoms.
Furthermore, the cationic group (H3NþCH2 CH2OH) on
one hand helps to balance the charge, and on the other
hand is formatting the H-bonds with the sulfur and oxygen
atoms. In addition, the H-bonds [N1-H1A … O1 (2.827 Å);
N1-H1B … O1 (2.011 Å and O3-H3 … S1 (2.457 Å)] between
the anionic and cationic groups further connected the mole-
cules in two 2D layer structures are presented in Figure 2
and Figure 3. And the 2D layer structures are packed into
3D network by the intermolecular interaction (Van der
Waals force) between the 2D structures.
Table 2. Selected bond distances (Å) and bond angles (ꢂ) of HADD.
Bond
Distances (Å)
Bond angles
Angles (ꢂ)
P (1) - O (2)
P (1) - O (1)
P (1) - S (2)
1.6163 (10)
1.6254 (10)
1.9632 (5)
1.9676 (5)
1.4953 (19)
1.4054 (17)
1.4077 (17)
1.4289 (17)
1.382 (2)
0.8264
O (2) - P (1) - O (1)
O (2) - P (1) - S (2)
O (1) - P (1) - S (2)
O (2) - P (1) - S (1)
O (1) - P (1) - S (1)
S (2) - P (1) - S (1)
C (1) - O (1) - P (1)
C (8) - O (2) - P (1)
C (6) - C (1) - C (2)
C (6) - C (1) - O (1)
C (2) - C (1) - O (1)
C (18) - C(8) - O (2)
C (12) - C(8) - O (2)
97.48 (5)
105.74 (4)
111.71 (4)
112.26 (4)
111.23 (4)
116.65 (2)
121.72 (9)
125.61 (9)
121.79 (14)
118.98 (13)
119.18 (13)
121.78 (13)
116.43 (13)
P (1) - S (1)
N (1) - C (14)
O (1) - C (1)
O (2) - C (8)
O (3) - C (13)
C (1) - C (6)
O (3) - H (3B)
N (1)- H (1 WC)
N (1) - H (1 WB)
N (1) - H (1 WA)
0.8642
0.8626
0.8650
Surface active properties
Herein, the surface tension (c) of HADD was measured for
a range of concentrations above and below the critical
micelle concentration (Ccmc). Figure 4 represents the plots
of c versus log C for HADD in double distilled water. An
the bond length of P (1) - S (2) (1.9632 (5) Å) is shorter
than the bond length of P (1) - S (1) (1.9676 (5) Å). The
different bond lengths and different bond angles (O (2) - P
(1) - O (1), O (2) - P (1) - S (2), O (1) - P (1) - S (2), O (2)
- P (1) - S (1), O (1) - P (1) - S (1), S (2) - P (1) - S (1)) obvious decrease in surface tension is observed with increas-
present that there is a distorted tetrahedral environment ing HADD concentration. This observation is recorded for

4
C. LAI ET AL.
Figure 5. Potentiodynamic polarization curves for Q235s in 1.0 M H2SO4 with
Figure 6. The effect of HADD concentration on inhibition efficiency (IEW, %).
different concentrations of HADD at 30 ꢂC.
(IEPPM, %) reaches to 98.41%. The increase of corrosion
inhibition effect is due to the gradual adsorption of HADD
on Q235s surface, resulting in a dense self-protective film,
which also indicates that HADD can act as an effective
inhibitor for Q235s in H2SO4 solution. Additionally, all cor-
rosion potential exhibited in Table 3 shifts less than 10 mV
(DE < 0.085 V), which reveals that HADD is a mixed-type
corrosion inhibitor.[11–16]
Table 3. The polarization parameter of Q235s corrosion in 1.0 M H2SO4 with
different concentrations of HADD at 30 ꢂC.
c
E
(V)
DE
(V)
iccd
ba
bc
IEPPM
(%)
(mg Lꢀ1
)
(lA cmꢀ2
)
(mV decꢀ1
)
(mV decꢀ1
)
0
40
100
150
200
250
ꢀ0.477
—
2887
2448
154.8
68.41
45.82
43.27
132.57
45.18
78.91
91.85
115.96
122.03
152.86
131.68
107.78
107.14
96.37
—
ꢀ0.497 0.020
ꢀ0.490 0.013
ꢀ0.482 0.005
ꢀ0.483 0.006
ꢀ0.479 0.002
42.81
89.66
97.63
98.41
98.50
97.20
Weight loss measurement
HADD up to the Ccmc, beyond which no considerable
changes are noticed, which is used to determine Ccmc of Figure 6 shows the effect of HADD concentration on inhibition
efficiency (IEW, %) for Q235s in 1.0 M H2SO4 at 30 ꢂC. Clearly,
HADD. The Ccmc data, obtained from the break point in the
c - log C plots, was 27.386 mmol Lꢀ1 and the surface ten-
the inhibition efficiency increase with the HADD concentration
increasing. As HADD concentration increases to 150 mg Lꢀ1
,
sion (ccmc) at Ccmc was 35.14 mN mꢀ1. Moreover, the max-
the inhibition efficiency changes only slightly when HADD con-
centration further increases. The increase of inhibition efficiency
is caused by the increasing of the coverage of HADD adsorbed
on the surface of Q235s. With HADD concentration rises to
150 mg Lꢀ1 and 200 mg Lꢀ1, the corresponding inhibition effi-
ciency are 97.83% and 98.96%, which further demonstrates that
HADD can act as an effective inhibitor.
imum surface pressure (pcmc
) can be obtained from
equation (1), where c0 (70.43 mN mꢀ1) was the surface ten-
sions of double distilled water at 30 ꢂC, and the calculated
value of pcmc was 35.29 mN mꢀ1. In addition, the c - log C
plots also provided information on area per molecule at air-
water interface, effectiveness and surface excess concentra-
tion of surfactant ions of HADD.
pcmc ¼ c0ꢀccmc
(1)
Adsorption isotherms
According to the data of weight loss measurement from Figure
6, various isotherms including Freundlich, Temkin, Flory -
Huggins, El - Awady and Langmuir adsorption isotherms were
employed to confirm the reasonable adsorption isotherm for
HADD on the Q235s surface. The five adsorption isotherms
for HADD on the Q235s surface in 1.0 M H2SO4 showed in
Figure 7a–e and Table 4. In Table 4, the R2 increases from
0.934 (in Freundlich adsorption isotherm) to 0.995 (in
Langmuir adsorption isotherm), revealing that the adsorption
of HADD on Q235s surface obeys Langmuir adsorption iso-
therm showed in equations (2) and (3).[6,8,17–20]
Potentiodynamic polarization measurement
Figure 5 presents the potentiodynamic polarization curves
(Tafel curves) for Q235s in 1.0 M H2SO4 with various con-
centrations (0–250 mg Lꢀ1) of HADD at 30 ꢂC. The electro-
chemical parameters are listed in Table 3, including IEPPM
(inhibition efficiency), iccd(i) (corrosion current density), E
(vs SCE, V) (corrosion potential), bc and ba (cathodic and
anodic Tafel slopes).
According to Figure 5 and Table 3, both anodic and cath-
odic curves shift to lower current densities with addition of
HADD into the H2SO4 solution. In Table 3, the current
density is much lower in the presence of HADD than that
in the absence of HADD in H2SO4 solution, and decreases
with increasing HADD concentration. When HADD con-
centration increases to 200 mg Lꢀ1, the inhibition efficiency
c
1
¼
þ c
(2)
h
K
v0ꢀvi
h ¼
(3)
v0

PHOSPHORUS, SULFUR, AND SILICON AND THE RELATED ELEMENTS
5
Figure 7. The plots of Freundlich (a), Temkin (b), Flory - Huggins (c), El - Awady (d) and Langmuir (e) adsorption isotherms for HADD on Q235 steel surface in 1.0 M
H2SO4 at 30 ꢂC.
DG0a ¼ ꢀRTlnð55:5KaÞ
(4)
(5)
Effect factors
In this work, the single factor experiment was employed to
study the effect of temperature (T, C), H2SO4 concentration
343 ꢁ 103
ꢂ
Ka ¼ MHADD ꢁ K ꢁ 103 ¼
30:6497
(CH, M) and immersion time (t, h) on inhibition efficiency
(IEW, %), and the relative results were listed in Table 5.
Obviously, all the factors involving temperature, H2SO4 con-
centration and immersion time can affect the corrosion
inhibition of Q235s in H2SO4 solution, among which the
temperature and H2SO4 concentration have particularly sig-
nificant effects on inhibition efficiency, while the immersion
time has a small effect. It is obviously seen that with the
temperature and H2SO4 concentration increasing, the inhib-
ition efficiency decreased sharply. When the temperature
increased from 10 ꢂC to 80 ꢂC, the inhibition efficiency
decreased from 99.76% to 28.77% for Q235s in 1.0 M
H2SO4, and the inhibition efficiency decreased from 99.47%
to 78.36% for Q235s in H2SO4 solution at 30 ꢂC by H2SO4
concentration increased from 0.1 M to 4.0 M. Furthermore,
the inhibition efficiency decreased slightly as immersion
time increasing, when immersion time decreased from 24 h
ꢀ1
¼ 1:1191 ꢁ 104 mol L
ð
Þ
Figure 7e shows the plots of c/h versus c yield the straight
lines. The strong correlation (R2 ¼ 0.995, see Figure 7e) sug-
gests the adsorption of HADD on Q235’s surface is con-
forming to Langmuir adsorption isotherm. Based on the
fitted results, DG0a (adsorption standard free energy) can be
determined by equation (4), where the value of intercept
(1/K, in equation (3)) is 30.6497 (mg Lꢀ1) that can be used
to calculate Ka shown in equation (5). The calculation is
shown
as
follows
DG0a ¼
ꢀ8.314 ꢁ 303.15 ꢁ ln
(55.5 ꢁ 1.1191 ꢁ 104) ¼ ꢀ33.62 (kJ molꢀ1), where the DGa0
for Q235s corrosion in 1.0 M H2SO4 with different concen-
trations of HADD at 30 ꢂC is ꢀ33.62 kJ molꢀ1 (> ꢀ40.00 kJ
molꢀ1) which also indicates that the adsorption processes of
HADD on Q235s surface belong to mixed adsorption
involving both physisorption and chemisorption.[7,9,21–23]

6
C. LAI ET AL.
to 192 h for Q235s in 1.0 M H2SO4 at 30 ꢂC, the inhibition Tensiometer (A101Plus, KINO Industry Co., Ltd, USA), and
efficiency only decreased from 97.33% to 95.84%. This slight the electrochemical tests were employed by electrochemical
workstation (CHI 760E, China).
decrease (1.49%) is attributed to the hydrolysis of HADD in
H2SO4 solution presented in Figure 8.
Synthesis and characterization of HADD
Experimental
Synthesis
Materials
According to the synthetic method described in our previ-
ous works,[4,6,8] hydroxyethyl ammonium O,O0-diphenyl
All analytically pure chemicals including toluene, phenol, phos-
phorus pentasulphide, ethanolamine and sulfuric acid (98%)
used to synthesize target compound and prepare aggressive
medium were not further purified before used. The working
electrode and test samples were prepared by Q235 steel
(Q235s) with the chemical compositions (wt.%) of Mn (0.531),
Si (0.270), C (0.187), P (<0.040), S (<0.045) and Fe (Bal.).
Moreover, the synthesized inhibitor was confirmed by
Fourier Transform infrared spectrometer (FT-IR, Nicolet
iS10, USA) and nuclear magnetic resonance (NMR, Bruker
av400, Germany). Crystal data were collected on a diffract-
ometer (SMART APEX-II, Bruker-AXS, Germany).
Meanwhile, the surface tension was measured by surface
dithiophosphate
([(PhO)2P(S)Sꢀ][H3Nþ
CH2CH2OH],
HADD) as a surfactant and corrosion inhibitor was pre-
pared by the reaction of phosphorus pentasulfide with phe-
nol and ethanolamine using toluene as the solvent under the
reflux condition. The synthetic route and corresponding
chemical structures of (PhO)2P(S)SH and [(PhO)2P(S)Sꢀ]
[H3NþCH2CH2OH]) are presented in Figure 9.
Characterization
FT-IR (KBr, cmꢀ1): 3365.1 (s), 3008.0 (m), 2937.1 (w),
1587.6 (s), 1484.9 (s), 1450.7 (m), 1207.5 (s), 1188.4 (s),
1162.4 (m), 1067.0 (m), 1004.8(m), 912.5 (s), 879.0 (s), 770.4
(s), 683.9 (s). 1H NMR (400 MHz, DMSO): d ¼ 2.86 (t,
J ¼ 5.2 Hz, 2 H, þNH3CH2), 3.58 (t, J ¼ 5.2 Hz, 2 H,
HOCH2), 5.16 (s, 1 H, OH), 7.05–7.08 (m, 2 H, o-PhH), 7.26
(dd, J ¼ 6.1, 5.1 Hz, 2 H, p-PhH), 7.29–7.34 (m, 4 H, m-
PhH), 7.70 (s, 3 H, þNH3) ppm.
Table 4. Fitting results of different adsorption isotherms for HADD on Q235s
in 1.0 M H2SO4 at 30 ꢂC.
Pearson’s R2
Equation (y ¼ a þ b x)
ꢃ
Number
Isotherms
ꢃ
(a)
(b)
(c)
(d)
(e)
Freundlich
Temkin
Flory - Huggins
El - Awady
Langmuir
0.93436
0.94583
0.98143
0.98933
0.99547
y ¼ 0.33162 x ꢀ 0.75961
ꢃ
y ¼ 0.57444 x ꢀ 0.32171
ꢃ
y ¼ 0.29087 x ꢀ 1.75068
ꢃ
y ¼ 2.59613 x ꢀ 4.09702
ꢃ
y ¼ 0.88247 x þ 30.6497 Surface tension measurement
Surface tension was measured for different concentrations of
HADD dissolved in double distilled water with a surface
Tensiometer (A101Plus, KINO Industry Co., Ltd, USA). At
30 ꢂC, the double distilled water was used to prepare test
Table 5. Effect of temperature (T, ꢂC), H2SO4 concentration (CH, M) and
immersion time (t, h) on inhibition efficiency for Q235s in H2SO4 solution by
weight loss measurements.
H2SO4
solutions with a surface tension 70.43 mN mꢀ1
.
Temperature
IEWLM
(%)
concentration
IEWLM
(%)
immersion
time (t, h)
IEWLM
(%)
(T, ꢂC)
(CH, M)
10
30
50
70
80
99.76
97.83
83.30
62.47
28.77
0.1
0.5
1.0
2.0
4.0
99.47
98.97
97.83
91.44
78.36
0
24
48
96
192
97.83
97.33
96.41
96.37
95.84
Weight loss measurement
Weight loss measurements to evaluate the corrosion inhib-
ition performance of steel in acidic solutions were described
Figure 8. The hydrolysis schematic of HADD in H2SO4 solution.
Figure 9. Synthetic process of hydroxyethyl ammonium O,O’-diphenyl dithiophosphate (HADD).

PHOSPHORUS, SULFUR, AND SILICON AND THE RELATED ELEMENTS
7
in our previous work and other researchers.[10,23–26] The
corrosion rate (v) and inhibition efficiency (IEWLM, %) were
obtained from equations (1) and (2), respectively.
m0ꢀmi
[2] Obot, I.-B.; Onyeachu, I.-B.; Wazzan, N.; Al-Amri, A.-H.
Theoretical and Experimental Investigation of Two Alkyl
Carboxylates as Corrosion Inhibitors for Steel in Acidic
Medium. J. Mol. Liq. 2019, 279, 190–207. DOI: 10.1016/j.mol-
liq.2019.01.116.
[3] Monticelli, C.; Balbo, A.; Esvan, J.; Chiavari, C.; Martini, C.;
Zanotto, F.; Marvelli, L.; Robbiola, L. Evaluation of 2-
(Salicylideneimino) Thiophenol and Other Schiff Bases as
Bronze Corrosion Inhibitors by Electrochemical Techniques
and Surface Analysis. Corros. Sci. 2019, 148, 144–158. DOI: 10.
1016/j.corsci.2018.12.017.
vi ¼
(6)
St
v0ꢀvi
ð Þ
IEWLM % ¼
ꢁ 100
(7)
v0
Potentiodynamic polarization measurement
[4] Lai, C.; Guo, X.-G.; Wei, J.; Xie, B.; Zou, L.-L.; Li, X.-L.; Chen,
Z.-X.; Wang, C.-M. Investigation on Two Compounds of O,O0-
Dithiophosphate Derivatives as Corrosion Inhibitors for Q235
Steel in Hydrochloric Acid Solution. Open Chem. 2017, 15,
263–271. DOI: 10.1515/chem-2017-0034.
According to potentiodynamic polarization measurement, the
potential sweep rate was set as 0.5 mV sꢀ1. The inhibition effi-
ciency (IEPPM, %) was calculated by equation (8).[27–30]
[5] Fernandes, C.-M.; Alvarez, L.-X.; Santos, N.-E.; Barrios, A. C.-
M.; Ponzio, E.-A. Green Synthesis of 1-Benzyl-4-Phenyl-1H-
1,2,3-Triazole, Its Application as Corrosion Inhibitor for Mild
Steel in Acidic Medium and New Approach of Classical
Electrochemical Analyses. Corros. Sci. 2019, 149, 185–194. DOI:
10.1016/j.corsci.2019.01.019.
iccdð0Þꢀiccd i
ð Þ ꢁ 100
(8)
ð Þ
IEPPM % ¼
iccd 0
ð Þ
Conclusions
[6] Su, X.-L.; Lai, C.; Peng, L.-C.; Zhu, H.; Zhou, L.-S.; Zhang, L.; Liu,
X.-Q.; Zhang, W. A Dialkyldithiophosphate Derivative as Mild
Steel Corrosion Inhibitor in Sulfuric Acid Solution. Int. J.
Electrochem. Sci. 2016, 11, 4828–4839. DOI: 10.20964/2016.07.101.
[7] Tan, B.; Zhang, S.-T.; Liu, H.-Y.; Guo, Y. W.; Qiang, Y.-J.; Li,
W.-P.; Guo, L.; Xu, C. L.; Chen, S.-J. Corrosion Inhibition of
X65 Steel in Sulfuric Acid by Two Food Flavorants 2-
Isobutylthiazole and 1-(1,3-Thiazol-2-yl) Ethanone as the Green
Environmental Corrosion Inhibitors: Combination of
Experimental and Theoretical Researches. J. Colloid Interf. Sci.
2019, 538, 519–529. DOI: 10.1016/j.jcis.2018.12.020.
[8] Wang, C.-D.; Lai, C.; Xie, B.; Guo, X.-G.; Fu, D.; Li, B.; Zhu,
S.-S. Corrosion Inhibition of Mild Steel in HCl Medium by S-
benzyl-O,O0-Bis(2-Naphthyl) Dithiophosphate with Ultra-Long
Lifespan. Results Phys. 2018, 10, 558–567. DOI: 10.1016/j.rinp.
2018.07.002.
[9] Lai, C.; Wei, J.; Guo, X.-G.; Xie, B.; Zou, L.-K.; Ma, X.; Zhu, S.-
S.; Chen, L.; Luo, G. B. Study on S-4-methylbenzyl-O,O0-
Dithiophosphates as Corrosion Inhibitors for Q235 Steel in HCl
Solution. Int. J. Electrochem. Sci. 2017, 12, 10457–10470. DOI:
10.20964/2017.11.16.
[10] Lai, C.; Xie, B.; Zou, L.-K.; Zheng, X.-W.; Ma, X.; Zhu, S.-S.
Adsorption and Corrosion Inhibition of Mild Steel in Hydrochloric
Acid Solution by S-allyl-O,O0-Dialkyldithiophosphates. Results Phys.
2017, 7, 3434–3443. DOI: 10.1016/j.rinp.2017.09.012.
In conclusion, the new compound of hydroxyethyl ammonium
O,O0-diphenyl dithiophosphate (HADD) acting as the anionic
surfactant and corrosion inhibitor was facilely synthesized and
1
characterized by FT-IR, H NMR and single crystal X-ray dif-
fraction. Study results indicate that HADD can be act as an
excellent surfactant and the Ccmc is 27.386 mmol Lꢀ1. Weight
loss measurement and potentiodynamic polarization measure-
ment results present that HADD is an effective corrosion
inhibitor, and the inhibition efficiency increased with HADD
concentration increasing and significantly decreased with both
temperature and H2SO4 concentration increasing. HADD turns
out to be a mixed-type effective corrosion inhibitor, which
obeys Langmuir isotherm being adsorpted on Q235s surface,
and it is a mixed adsorption involving both the physisorption
and chemisorption mechanism.
Disclosure statement
No potential conflict of interest was reported by the authors.
[11] Lai, C.; Xie, B.; Liu, C.-L.; Gou, W.; Zhou, L.-S.; Su, X.-L.; Zou,
Funding
L.-L.
A
Study of N,N-Diethylammonium O,O0-di(p-
Methoxyphenyl)Dithiophosphate as New Corrosion Inhibitor
for Carbon Steel in Hydrochloric Acid Solution. Inter. J. Corros.
2016, 2016, 1–8. DOI: 10.1155/2016/1907634.
This project is supported financially by the opening project of Key
Laboratories of Fine Chemicals and Surfactants in Sichuan Provincial
Universities (2018JXZ01, 2016JXZ03), the projects of Sichuan University of
Arts and Science (2018SCL001Z, 2018KC005Z), the program of Science
and Technology Department of Sichuan Province (2018JY0061), the pro-
gram of Education Department of Sichuan Province (18CZ0038), and the
project of Dazhou City (18ZDYF0008, 18ZDYF0009).
[12] Zhang, G. A.; Hou, X. M.; Hou, B. S.; Liu, H. F. Benzimidazole
Derivatives as Novel Inhibitors for the Corrosion of Mild Steel
in Acidic Solution: Experimental and Theoretical Studies. J.
Mol. Liq. 2019, 278, 413–427. DOI: 10.1016/j.molliq.2019.01.
060.
[13] Rabizadeh, T.; Asl, S.-K. Casein as a Natural Protein to Inhibit
the Corrosion of Mild Steel in HCl Solution. J. Mol. Liq. 2019,
276, 694–704. DOI: 10.1016/j.molliq.2018.11.162.
ORCID
[14] Pohrebova, I.-S.; Pylypenko, T.-M. Inhibitors for Acid
Corrosion of Metals Based on Quaternary Pyridinium Salts
Containing Carbonyl Groups. Mater. Today: Proc. 2019, 6,
192–201. DOI: 10.1016/j.matpr.2018.10.094.
[15] Luo, X.-H.; Ci, C.-G.; Li, J.; Lin, K.-D.; Du, S.; Zhang, H.-X.; Li,
X.-B.; Cheng, Y.-F.; Zang, J.-C.; Liu, Y.-L. 4-aminoazobenzene
Chuan Lai
http://orcid.org/0000-0001-6213-4598
References
[1] AfifAnaee, R.; Tomi, I. H.-R.; Abdulmajeed, M.-H.; Naser, S.-
A.; Kathem, M.-M. Expired Etoricoxib as a Corrosion Inhibitor
for Steel in Acidic Solution. J. Mol. Liq. 2019, 279, 594–602.
DOI: 10.1016/j.molliq.2019.01.169.
Modified Natural Glucomannan as
a Green Eco-Friendly
Inhibitor for the Mild Steel in 0.5 M HCl Solution. Corros. Sci.
2019, 151, 132–142. DOI: 10.1016/j.corsci.2019.02.027.

8
C. LAI ET AL.
[16] Murmu, M.; Saha, S.-K.; Murmu, N.-C.; Banerjee, P. Effect of
Stereo Chemical Conformation into the Corrosion Inhibitive
Behaviour of Double Azomethine Based Schiff Bases on Mild
Steel Surface in 1 Mol Lꢀ1 HCl Medium: An Experimental,
Density Functional Theory and Molecular Dynamics Simulation
Study. Corros. Sci. 2019, 146, 134–151. DOI: 10.1016/j.corsci.
2018.10.002.
Investigation. J. Ind. Eng. Chem. 2019, 69, 18–31. DOI: 10.
1016/j.jiec.2018.09.013.
[24] Verma, D.-K.; Ebenso, E.-E.; Quraishi, M.-A.; Verma, C.
Gravimetric, Electrochemical Surface and Density Functional
Theory Study of Acetohydroxamic and Benzohydroxamic Acids
as Corrosion Inhibitors for Copper in 1 M HCl. Results Phys.
2019, 13, 102194. DOI: 10.1016/j.rinp.2019.102194.
[17] Ituen, E.; Akaranta, O.; James, A. Corrosion Inhibition
Characteristics of 2-[(E)-[5-Methoxy-1-[4-(Trifluoromethyl)Phenyl]
Pentylidene]Amino]Oxyethanamine on Steel in Simulated Oilfield
Acidizing Solution. J. King Saud Univ. Eng. Sci. 2019, 31, 191–199.
DOI: 10.1016/j.jksues.2017.07.002.
[18] Popoola, L.-T. Progress on Pharmaceutical Drugs, Plant
Extracts and Ionic Liquids as Corrosion Inhibitors. Heliyon
2019, 5, e01143. DOI: 10.1016/j.heliyon.2019.e01143.
[19] Shaban, S.-M.; Aiad, I.; Moustafa, A.-H.; Aljoboury, O.-H. Some
Alginates Polymeric Cationic Surfactants; Surface Study and Their
Evaluation as Biocide and Corrosion Inhibitors. J. Mol. Liq. 2019,
276, 164–176. DOI: 10.1016/j.molliq.2018.10.017.
[20] Vasyliev, G.; Vorobiova, V. Rape Grist Extract (Brassica Napus) as
a Green Corrosion Inhibitor for Water Systems. Mater. Today:
Proc. 2019, 6, 178–186. DOI: 10.1016/j.matpr.2018.10.092.
[21] Gong, W.-N.; Yin, X.-S.; Liu, Y.; Chen, Y.; Yang, W.-Z. 2-
Amino-4-(4-Methoxyphen yl)-Thiazole as a Novel Corrosion
Inhibitor for Mild Steel in Acidic Medium. Prog. Org. Coat.
2019, 126, 150–161. DOI: 10.1016/j.porgcoat.2018.10.001.
[22] Zhang, Q.-H.; Hou, B.-S.; Xu, N.; Liu, H.-F.; Zhang, G.-A. Two
Novel Thiadiazole Derivatives as Highly Efficient Inhibitors for
the Corrosion of Mild Steel in the CO2-Saturated Oilfield
Produced Water. J. Taiwan Inst. Chem. Eng. 2019, 96, 588–598.
DOI: 10.1016/j.jtice.2018.11.022.
[25] Obot, I.-B.; Umoren, S.-A.; Ankah, N.-K. Pyrazine Derivatives
as Green Oil Field Corrosion Inhibitors for Steel. J. Mol. Liq.
2019, 277, 749–761. DOI: 10.1016/j.molliq.2018.12.108.
[26] Mobin, M.; Basik, M.; Aslam, J. Pineapple Stem Extract
(Bromelain) as an Environmental Friendly Novel Corrosion
Inhibitor for Low Carbon Steel in 1 M HCl. Measurement 2019,
134, 595–605. DOI: 10.1016/j.measurement.2018.11.003.
[27] Dehghani, A.; Bahlakeh, G.; Ramezanzadeh, B.; Ramezanzadeh,
M. Potential of Borage Flower Aqueous Extract as an
Environmentally Sustainable Corrosion Inhibitor for Acid
Corrosion of Mild Steel: Electrochemical and Theoretical
Studies. J. Mol. Liq. 2019, 277, 895–911. DOI: 10.1016/j.molliq.
2019.01.008.
[28] Javidi, M.; Chamanfar, R.; Bekhrad, S. Investigation on the
Efficiency of Corrosion Inhibitor in CO2 Corrosion of Carbon
Steel in the Presence of Iron Carbonate Scale. J. Nat. Gas Sci.
Eng. 2019, 61, 197–205. DOI: 10.1016/j.jngse.2018.11.017.
[29] Likhanova, N.-V.; Arellanes-Lozada, P.; Olivares-Xometl, O.;
ꢀ
Hernandez-Cocoletzi, H.; Lijanova, I.-V.; Arriola-Morales, J.;
Castellanos-Aguila, J.-E. Effect of Organic Anions on Ionic
Liquids as Corrosion Inhibitors of Steel in Sulfuric Acid
Solution. J. Mol. Liq. 2019, 279, 267–278. DOI: 10.1016/j.mol-
liq.2019.01.126.
[30] Macedo, R. G. M.-A.; Marques, N.-N.; Tonholo, J.; Balaban, R.-
C. Water-Soluble Carboxymethylchitosan Used as Corrosion
Inhibitor for Carbon Steel in Saline Medium. Carbohyd. Polym.
2019, 205, 371–376. DOI: 10.1016/j.carbpol.2018.10.081.
[23] Sanaei, Z.; Ramezanzadeh, M.; Bahlakeh, G.; Ramezanzadeh, B.
Use of Rosa Canina Fruit Extract as a Green Corrosion
Inhibitor for Mild Steel in 1M HCl Solution: A Complementary
Experimental, Molecular Dynamics and Quantum Mechanics