Synthesis of Lubricant s Additives

230 Pages·2014·4.13 MB·English

Ministry of Higher Education and Scientific Research
University of Baghdad – College of Science
Department of Chemistry

’
Synthesis of Lubricant s Additives

A Thesis
Submitted to the College of Science - University of Baghdad
In Partial Fulfillment of the Requirements for
Degree of Doctor Philosophy in Organic Chemistry

By

Zainab Abdulzahra Khuthair AL-Messri

B.Sc. (Baghdad University 1994)
M.Sc. (AL-Nahrain University 1999)

Supervisors

Prof. Dr. Mohammed R. Ahmad Prof. Dr. Abdul Halim A-K Mohammed

2013 A. D. 1434 A. H.
ﻢﻴﻈِ ﻌﻟا ﻲِﻠﻌﻟا ﻪﱠﻠﻟا قﺪﺻ
ُ َ ﱡ َ ُ َ َ َ

ءاﺮﻌﺸﻟا ةرﻮﺳ ﻦﻣ
Dedicate to:

The light of my life…
My father
with love and respect

&

The real friend and sister…
Israa
with appreciation

Zainab
ACKNOWLEDGEMENTS

I would like to express my gratitude to the many people that helped
in different ways towards the completion of this work. My primary thanks
to my supervisors Prof. Mohammed R. Ahmad and Prof. Abdul Halim
A-K Mohammed, for their support, guidance and discussion of my work.
I also thank Prof. Yousif Ali, who helped me not only with this thesis,
but with acquiring scientific knowledge and skills.

My deep gratitude to Prof. Mousa Almousawi, Prof. Abdul
Jabar Kadir, Prof. Issam M.A. Shakir, Ass. Prof. Basim .I. Al-
Abdali, Prof. M. Shanshal, and Ass. Prof. Mohammed H. Al-Ameri
for their supporting, and encouragement.

Sincere thanks to the Ministry of Higher Education and
Scientific Research for providing free, and full-text access to the
scientific journals according to Iraq Virtual Science Library.

Thanks are offered to the Department of chemistry, College of
Science, University of Baghdad for providing the facilities.

I gratefully acknowledge financial support by the Petroleum R&D
Center /Ministry of Oil. A special thanks to Mr. Salah M. Ali for his
assistance and encouragement.

I am very grateful to Dr. Abdulkareem Mohammed Ali, for
modifying a domestic microwave oven to microwave irradiation reactor.
My special thanks, and gratitude to Prof. Issam M.A. Shakir and
Prof. Nagham S. Turkie , for the (ANOVA) tests.

Thanks are also due to Midland Refineries Company/ Iraq for
providing the base oils and the analyses of oxidation stability, especially
Mr. Ayad A. Mohamad , Mr. Yousif T. Abdulhameed, and the lab
technicians and chemists (Bacil Al-Dabbagh, Mohammed Ahamad,
Basam Al-Qaicy, Mohammed Saaed, Mustafa Al-Bassam and Ahmed
Abdulzahra) who helped in the analysis.

I am very grateful, and appreciate for all the help and support from
Ass. Prof. Suaad M. Al-Majidi.

Sincere thanks to Prof. Intisar Altamemi, Prof. Ahlam M.
Farhan, Prof. Khulood Al-Saadie, Dr. Thanaa Almuamen, and Mrs.
Hanaa J. Hamoudi for their supporting and encouragement.

A special thanks to Dr. Ghadah A. Yiseen, Middle East Technical
university , Turkey and to Dr. Naeema J. Lami, Cardiff University, U.K.,
for NMR analysis. Also, I would like to thank Ms. Muneera, and Mrs.
Haifaa for their kind assistance in Infra red analysis.

Sincere thanks goes to my best friends (Israa, Saba, Nada, Jwan,
Thikra, Hind, Dalia, Huda, Nasreen, Hiba, and Yasmeen), and to my
colleagues (Mr. Ali Muayad, Muntader, Rafid, Ali Saad and Oday) for
their continuous support and help.

Finally, my respect and appreciation to my professor and mother
Prof. Suad M. AL-Aaraji, and to my dear father.
Summary
Overbased detergent additives were synthesized and investigated as
viscosity index improvers, and pour point depressant. New antioxidant
additives containing pyranopyrazole and pyranopyrimidine moieties were
synthesized and evaluated as lubricating oil additives.

A series of overbased magnesium fatty acids (D1-D7) such as
caprylate, caprate, laurate, myristate, palmitate, stearate and oleate, were
synthesized by the reaction of the fatty acids in toluene / ethanol solvent
mixture (9:1vol./vol.) with magnesium oxide and carbon dioxide gas at
60 oC in the presence of ammonia solution. Moreover overbased calcium
palmitate, stearate and oleate (D8-D10), were synthesized by the same
method, using calcium oxide and calcium hydroxide instead of
magnesium oxide.

The prepared detergent additives were characterized and confirmed
by FTIR, and 1HNMR. All these compounds were evaluated by blending
each additive in various concentrations (1-5% wt/wt) with medium
lubricant oil fraction (60 stock) supplied by Iraqi Midland Refineries
Company. The total base number (TBN, mg of KOH/g oil) was
determined. Overbased magnesium palmitate D5, oleate D6, and stearate
D7 detergents gave the higher TBN and efficiency.

The oil blends with 2% of overbased magnesium palmitate and
overbased magnesium stearate detergents were proved to have excellent
oxidation stability compared with the blends of standard antioxidant
supplied by Midland Refineries Company.

I
The efficiency of the prepared overbased magnesium palmitate and
overbased magnesium stearate as viscosity index improvers, were
investigated. It was found that the efficiency of the prepared compound as
viscosity index improvers increases with increasing the concentration of
additives and with increasing the molecular weight of prepared
compounds. The overbased magnesium stearate D7 in 5 wt.%
concentration gave the higher efficiency as viscosity index improvers,
and a good pour point depressant.

Antioxidant additives containing pyranopyrazole and
pyranopyrimidine moieties, were synthesized from 2-(4-
hydroxylbenzylidine) malononitrile (S3), which was obtained from the
reaction of 4-hydroxy benzaldehyde and malononitrile in presence of
pipridine in ethanol under microwave irradiation.

Reaction of S3 with three different types of carbanion compounds
3-methyl-1-phenyl-2-pyrazolin-5-one (S1), 3-methyl -2-pyrazolin-5-one
(S2), 5,5-dimethyl-1,3-cyclohexandion (dimedone) and pyrimidine-
2,4,6(1H,3H,5H)-trione (barbituric acid) under microwave irradiation
gave 6-amino-4-(4-hydroxyphenyl)-5-cyano-3-methyl-1-phenyl-1,4-
dihydropyrano[2,3-c]pyrazole (A1), 6-amino-4-(4-hydroxy phenyl)-5-
cyano-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole (A11), 5-(4-
hydroxyphenyl)-8,8-dimethyl-8,9-dihydro-3H-chromeno-5-cyano-1,4-
dihydropyrano[2,3-c]pyrazole (A۱۷) and 7-amino-5-(4-hydroxyphenyl)-
2,4-dioxo-2,3,4,5-tetrahydro-1H-pyrano[2,3-d]pyrimidine-6-carbonitrile
(A26) respectively.

The compound A1 was reacted with formic acid, formamide and
ammonium thiocyanate under microwave irradiation to prepare 4-(4-
hydroxyphenyl)-3-methyl-1-phenyl-4,6-dihydro-pyrazolo[3',4':5,6]pyrano
II
[2,3-d]pyrimidine-5-one (A2), 4-(4-hydroxyphenyl)-3-methyl-1-phenyl-
4,6-dihydro-pyrazolo[3',4':5,6]pyrano[2,3-d]pyrimidine-5-imine (A3) and
N-[4-(4-hydroxyphenyl)-3-methyl-1-phenyl-7-thioxo-7,8dihydropyrazolo
[3',4':5,6]pyrano[2,3-d]pyrimidine-5-yl]thiourea (A4) respectively.
Moreover the compound (A1) was then reacted with different aromatic
aldehydes which gave the corresponding Schiff’s base derivatives (A5-
A10).
Schiff’s base derivatives (A12-A16) were obtained from the
reaction of the compound A11 with different aromatic aldehydes in the
presence of drops of acetic acid under microwave irradiation.
Compounds (A18-A20) and (A21-A25) were synthesized in a similar
manner that used for preparation of (A2-A4) and (A5-A10) respectively.

Most of the prepared compounds were characterized by FTIR,
1HNMR, 13CNMR and evaluated as antioxidant additives by blending 1%
of each compound with base oil 60 stock.

The oxidation stability of blends was examined according to
Institute of Petroleum testing method IP 280. Inhibited oil was subjected
to severe oxidation condition in the presence of a soluble iron and copper
catalyst at 120ο C for 164 hours while being subjected to a constant one-
liter/hour flow of oxygen. From this test the volatile acids, the acidity of
the oil and the precipitated sludge were measured and their values were
used to calculate the total oxidation products (TOP).

The oxidation stability study revealed that many of the tested
compounds showed good to moderate antioxidant activities. While, the
derivatives A4, A5, A7, A20, A21, A23, and A26 showed better
oxidation stability than the standard antioxidant supplied by Midland
Refineries Company.
III
List of Contents
Chapter One
1.1 Lubricants 1
1.1.1 Lubricant Properties 2
1.1.1.1 Viscosity 2
1.1.1.2 Viscosity Index 2
1.1.1.3 Density and Gravity 3
1.1.1.4 Pour Point 4
1.1.1.5 Volatility and Flash Point 4
1.1.1.6 Total Base Number 4
1.1.1.7 Oxidation Stability 5
1.1.2 Lubricants chemistry 7
1.1.3 Lubricants production 9
1.1.4 Lubricants Formulation 11
1.2 Additives 13
1.2.1 Detergents 15
1.2.2 Dispersants 15
1.2.3 Antiwar Additives 15
1.2.4 Rust and Corrosion Inhibitors 16
1.2.5 Viscosity Modifiers 16
1.2.6 Pour Point Depressants 16
1.2.7 Foam Inhibitors 16
1.2.8 Oxidation Inhibitors 17
1.3 Overbased detergent 17
1.3.1 Synthesis of Overbased Detergents 18
1.3.2 Overbasing Description 19
IV
1.3.3 Overbased Detergent Structure 19
1.3.4 Overbased Detergent Types 20
1.3.4.2 Phenates 20
1.3.4.3 Carboxylate and Salicylates 21
1.4 Antioxidants 22
1.4.1 Oxidation Mechanism 24
1.4.1.1 Initiation of the Radical Chain Reaction 24
1.4.1.2 Propagation of the radical chain reaction 25
1.4.1.3 Chain branching 25
1.4.1.3 Chain branching 26
1.4.1.4 Termination of the radical chain reaction 26
1.4.2 Oxidation Inhibition 27
1.4.2.1 Radical Scavengers 27
1.4.2.1.1 Phenols 27
1.4.2.1.2 Amines 28
1.4.2.2 Peroxide Decomposers 30
1.4.2.3 Metal deactivators 31
1.5 Pyrazole 32
1.6 Pyranopyrazoles 33
1.7 Chromene 38
1.8 2-Amino-3-cycano-4-aryl-7,7-dimethyl-5,6,7,8-tetrahydro 40
chromene
1.9 Aim of the work 44
Chapter Two
2.1 Materials 45
2.1.1 Chemicals 45
V