Synthesis of lubricant’s additives

Other Title(s)

تخليق محسنات الزيوت

Dissertant

al-Misri, Zaynab Abd al-Zahrah Khudayr

Thesis advisor

Muhammad, Abd al-Halim Abd al-Karim
Khalil, Muhammad Rifat Ahmad

University

University of Baghdad

Faculty

College of Science

Department

Chemistry Department

University Country

Iraq

Degree

Ph.D.

Degree Date

2013

English Abstract

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.

II 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 III [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 oneliter/ 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.

Main Subjects

Chemistry

No. of Pages

205

Table of Contents

• APA
• MLA
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Language

English

Data Type

Arab Theses

Record ID

BIM-600623