final report 2.docx

JOMO KENYATTA UNIVERSITY OF AGRICULTURE AND TECHNOLOGY CHEMISTRY DEPARTMENT USE OF MODIFIED CROTON MEGALOCARPUS SEED OIL AS A REACTIVE DILUENT IN ALKYD COATINGS. BY LORNA TEYIAN NTIPILIT Signature…………… Date……………… FOURTH YEAR BACHELOR OF SCIENCE (INDUSTRIAL CHEMISTRY) SUPERVISORS PROF.GEORGE THUKU THIONGO Signature…………….. Date…………… Dr. PARTRICK M MWANGI Signature…………….. Date…………… A PROJECT REPORT SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF BACHELOR OF SCIENCE INDUSTRIAL CHEMISTRY OF JOMO KENYATTA UNIVERSITY OF AGRICULTURE AND TECHNOLOGY. ACADEMIC YEAR 2014/2015  DECLARATION This is to confirm that I, Ntipilit Lorna Teyian, whose registration number and signature appears below, undertook this project as my final year project. I also confirm that this is my original work and has not been presented in this or any other university for examination or for any other purposes. Ntipilit Lorna Teyian Reg. No: SC 233-1441/2010 Signature …………………………………. Date …………………………………... CERTIFICATION I confirm that the researcher under my supervision prepared the work presented in this research paper. I hereby confirm the handing in of the final project report. SUPERVISORS: PROF.GEORGE THUKU THIONGO Signature……………… …. Date………………. Dr. PARTRICK M MWANGI Signature……………………. Date…………………  ACKNOWLEDGEMENTS To all those who in one-way or another contributed in making this project a success and to all those who endeavor to make this world a better place to live and work in. Special thanks however go to the following people for the great role they played in this project: My supervisors Prof .George T. Thiong’o and Dr.Patrick M. Mwangi for their guidance and assistance throughout this project. The entire chemistry department for their technical and material support. To the laboratory staff of Jomo Kenyatta University of Agriculture and Technology, BEED department for provision of the C.megalocarpus oil, CPC department for provision of coating materials. To my classmates for their resourceful ideas, which they were always willing to share and providing a good environment for learning. My entire family for their love, support, and encouragement. Above all to God without whom I would not be where I am today. ABSTRACT Fatty acids methyl esters derived from vegetable oil (VO) can be introduced as a reactive diluent in alkyd coatings. Reactive diluents give a more environment coating. Vegetable oils are considered to be among the most promising renewable raw materials for polymers because they are readily available, they are biodegradable, non-toxic, low cost, and are capable of competing with fossil fuel derived petro based product. The outstanding feature of vegetable oils is their unique chemical structure with unsaturated sites, hydroxyls, esters and other functional groups along with inherent fluidity characteristics. These enable them to undergo various chemical transformations producing low molecular weight polymeric materials with versatile applications, particularly as chief ingredients in paints and coatings. They can be divided into non-drying, semi-drying and drying oils. Croton megalocarpus vegetable oil was obtained from BEED department which had been obtained by pressing from croton seed. Parameters of the crude vegetable oil were determined such as acid value 22.21mgKOH/g, free fatty acids 11.11mgKOH/g, viscosity value 11.56centipoises, specific gravity 0.919, pH 5.3, saponification value 127.35 and iodine value137.5. The oil was then transesterified and left to stand overnight. A separation of two layers was obtained. The upper layer was the methyl ester and the lower layer being glycerol. The methyl ester was decanted from glycerol and methanol distilled off. It was then washed, dried and filtered. The methyl esters had an acid value of 0.2984mgKOH/g, percentage free fatty acids 0.1492mgKOH/g, viscosity 5.56 centipoises, specific gravity of 0.877, pH of 7.1, saponification value of 216.2 and iodine value of 136 . The results show that the physical tests carried out on the methyl ester met the American Standards for Testing Materials (ASTM). The methyl esters were used as reactive diluents in the formulation of varnish. Viscosity and drying time were determined for the different formulations of varnish. TABLE OF CONTENTS DECLARATION i CERTIFICATION i ACKNOWLEDGEMENTS ii ABSTRACT iii TABLE OF CONTENTS iv LIST OF ABBREVIATIONS, UNITS AND ACRONYMS vii Metric units vii List of Acronyms vii 1. INTRODUCTION 1 1.1. Coatings 1 1.2 Vegetable oils in coatings 1 1.3 Reactive Diluents 2 1.4 Croton Megalocarpus. 3 1.5 Transesterification of Vegetable Oils 3 2.0 LITERATURE REVIEW 5 2.1 Composition of Natural Oils 5 2.2 Modified Vegetable Oil 6 2.3 Previous Studies of Reactive Diluents 6 2.4 Alkyd Resins 7 2.5 Autoxidation 7 2.6 Fatty Acid Autoxidation 7 2.7 Solvents 8 2.8 Atmospheric Photochemical Effects 9 3.0 PROBLEM STATEMENT 10 4.0 JUSTIFICATION 10 5.0 Objectives 10 5.1 Main Objective 10 5.2 Specific Objectives 10 6.0 HYPOTHESIS 10 7.0 METHODOLOGY 11 7.1 Experimental 11 Acid Value and Percentage Free Fatty Acid Determination 11 Viscosity Determination 11 Specific Value Determination 12 Saponification Value Determination 12 Ester Value 12 Iodine Value Determination 13 8.0 RESULTS TURBULATIONS AND ANALYSIS 14 8.1CRUDE OIL PROPERTIES MEASUREMENTS 14 Acid Value and Percentage Free Fatty Acid Determination 14 Viscosity Determination 15 pH Determination 15 Saponification Value Determination 16 Iodine Value Determination 17 FTRI ANALYSIS 18 8.2 TRANSESTERIFICATION PROCESS 20 8.3 WASHING 21 8.4 PERCENTAGE YIELD 21 8.5METYL ESTER PROPERTIES MEASUREMENTS 22 Acid Value and Percentage Free Fatty Acid Determination 22 Viscosity Determination 23 Specific Value Determination 23 pH Determination 23 Saponification Value Determination 24 Iodine Value Determination 25 FTRI ANALYSIS 26 9.0 RESULTS ANALYSIS 28 10.0 DISCUSSION 29 TRANSESTERIFICATION PROCESS 29 ACID VALUE AND PERCENTAGE FREE FATTY ACIDS 29 SAPONIFICATION VALUE 29 SPECIFIC VALUE 30 pH VALUE 30 VISCOSITY 30 IODINE VALUE 30 11.0 FORMULATION OF VARNISH 31 11.1) RESULTS 32 11.2) DISCUSSION 33 12.0) CONCLUSION 34 13.0) RECOMMENDATIONS 34 REFERENCES 35 LIST OF ABBREVIATIONS, UNITS AND ACRONYMS Metric units M meter Mg milligram g grams Ml millimeter Kg kilograms 0C degree Celsius (centigrade) L liters List of Acronyms VO vegetable oils VOCs volatile organic compounds EPA The United States Environmental Protection Agency HAPs hazardous air pollutants MEK methyl ethyl ketone MIBK methyl isobutyl ketone POCP photochemical ozone creation potential. OFS fumarates and succinates of octadienol MF melamine-formaldehyde () resins UF urea-formaldehyde () ASTM- American Standard for Testing Materials   INTRODUCTION Coatings The origin of paints dates back to pre-historic times when the early inhabitants of the earth recorded their activities in colors on the walls of their caves. The Egyptians developed the art of painting by 1500BC had a large number and variety of colors. By 1000BC they discovered the forerunner of our present-day varnishes, usually naturally occurring resins or beeswax were the film-forming ingredients. Surface coatings have been divided into paints, varnishes, enamel, lacquers printing inks, polishes. Surface coatings are essential for the prevention of all types of architectural structures, from ordinary attacks of weather. Uncoated wood or metal are susceptible to deterioration especially in areas where soot and Sulphur (IV) Oxide accelerate such action. Aside from their purely protective action, paints, varnishes and lacquers increase the attractiveness of manufactured goods. (George. T. A., 1984). The consumer and industrial interest in the development of eco-friendly materials have catapulted the environmentally benign agricultural resources as feedstocks of the polymer induced industry. Today due to interdisciplinary approaches through research and technological innovations in oleo-chemistry, biosciences, biotechnology and engineering it is possible to design eco-friendly chemicals from nature’s abundant renewable resources. Polymers are obtained from renewable resources such as starch, lignin, protein, cellulose, wool fibers, polyhydroxylalkanoates and vegetable oils. They find industrial applications such as plasticizers, biodiesels, lubricants, adhesives, biodegradable packaging materials, printing inks, paints and coatings. 1.2 Vegetable oils in coatings Vegetable oils (VO) are non-toxic, non-depletable, non-volatile and biodegradable resources. They yield polymers capable of competing with fossil fuels derived petro-based products. Such polymers find application in the development of paints and surface coatings besides their other industrial applications. (Larok and Lu, 2009). Vegetable oils were one of the first kinds of binders for coatings and have been used in different coating applications for centuries. They have been used as crude air-drying oils, e.g. linseed oil, and as components in resin structures, e.g. in alkyds (Z. W. Wicks et al,. 1999). Vegetable oils are triglycerides, i.e. triesters of glycerol and fatty acids. The fatty acid structure of a triglyceride may be the same or vary in chain length and amount of double bonds, i.e. the oil is a mixture of fatty acids. The vegetable oils can be divided into three groups; non-drying, semi-drying, and drying oils, depending on their fatty acid pattern. Non-drying oils contains saturated fatty acids that cannot be cross linked by air oxidation. Olive oil and castor oil are examples of non-drying oils. Semi-drying oils contains one or two unsaturation’s that slowly can cross-link through oxidation. The semi-drying oil film will never be completely tack-free. Soybean and tall oil are semi-drying oils. Drying-oils are highly unsaturated oils that air oxidizes to a tack-free film with time. A drying-oil is traditionally defined as oil with an average number of diallylic groups per molecule greater than 2.2. Linseed and tung oil are commonly used as drying-oils (D. H. Solomon, 1982). As vegetable oils are renewable materials, lots of research has been performed to find new fields of application, e.g. epoxidized oils as plasticizers and stabilizers for vinyl plastics, reactive diluent, and printing ink (Muturi et al,. 1994). Today, due to several environmental and health hazards cropping up from fossil fuel derived products and tear of depletion of petroleum resources by the end of 21st century, the polymer chemist and technologists have reverted to the extensive utilization of VOs derived materials in paints and coatings. In the coating industry drying oils and alkyds have been used for decades as renewable natural binders for various coating applications, including varnishes and paints. Unfortunately, in order to formulate them into a proper product for coatings, drying oils and alkyds require the incorporation of volatile organic compounds (VOCs) to satisfy the coatings application, especially the viscosity application. In addition, drying oils and alkyds-based materials are generally inferior in material properties compared to those of petrochemical derivative products. (Wicks Z. W. et al,. 1999). The United States Environmental Protection Agency (EPA) specified the limit of VOCs usage in varnish and paint formulations, which has created enormous pressure on the varnish and paint industries to reduce solvent emissions. One possible solution to resolve this regulation problem is to develop a reactive diluent which would function as a solvent in the formulation of the coating, but which, during the cure process, is converted to an integral part of the film. 1.3 Reactive Diluents A reactive diluent is defined as a compound that acts as a solvent in the liquid paint, lowering the viscosity and chemically reacts into the final film during cure. The reactive diluent must have a functional group that can react with the other coating components during cure. The functional groups must be of the right amount and reactivity degree to prevent in-can storage problems, retarding of the drying, and remains of non-reacted reactive diluent working as plasticizer in the final film ( Lindeboom, 1998). An ideal reactive diluent exhibits excellent solvency behavior such as lowering viscosity, good compatibility, low volatility, and low toxicity. In addition, if the reactive diluent could be derived from a bio-based resource, it would have a greater positive environmental impact since it would not only reduce the VOC content but also introduce a renewable material into the final film. As a result, seed-oil based materials are an attractive choice for reactive diluents, since seed oils are biodegradable and readily available from renewable resources. Seed oils are triglycerides of fatty acids. Seed oils such as linseed oil, soybean oil, or tung oil can form a networked polymer film when exposed to air and are often used in the manufacture of coatings binders.  1.4 Croton Megalocarpus. C. megalocarpus is a large forest tree (15-36 m height) of Euphorbiaceous family. In Swahili it is called Msenefu and Lameruguet in Samburu. It occurs in tropical East Africa, with an altitude range of 1,400 m to 2,300 m; it is mainly planted as a shade tree in coffee plantations (Chudnoff, 1984). It is estimated that mature tree can produce up to 30 kg or more of brown oval shaped seeds per season (Figure 1) (Makayoto, 1985). The seeds give faintly yellow semi-drying oil. East African C. megalocarpus seed has been reported to yield 49% oil which is hemolytic and purgative, of which 78% is octadeca-9,12-dienocic acid (C18:2) (Munavu, 1983b). Figure 1: C. megalocarpus tree and dried seeds. The highly unsaturated oil can be used as drying oil in paint formulations and as fuel since it is similar to sunflower oil, which has been shown to be suitable diesel substitute (Antolin et al., 2002). Croton seed contains carcinogenic fatty acids esters of phorbol, and poisonous alkaloids. 1.5 Transesterification of Vegetable Oils Transesterification describes important class of organic reactions where an ester is transformed into another through interchange of alkoxy moiety. Triglyceride reacts with an alcohol in presence of a strong acid or base catalyst producing a mixture of fatty acid alkyl esters and glycerol, Scheme 1  The overall process is a sequence of three consecutive and reversible reactions, in which diglyceride and monoglyceride are formed as intermediate, (Freedman et al., 1986). The proposed mechanism for the reaction is shown in Scheme 2. Several aspects, including the type of catalyst, alcohol to vegetable oil molar ratio, temperature, water content and free fatty acids have been singled out to have an influence on the course of Transesterification (Meher et al., 2006). Alkaline catalysis is preferred because of less corrosive nature and the fact that the reaction proceeds much faster than in acid catalyzed reaction (De Oliveira et al., 2005). Metal hydroxides (KOH and NaOH) are used often because they are cheaper than metal alkoxides (Schuchardt et al., 1997).  2.0 LITERATURE REVIEW 2.1 Composition of Natural Oils The major component of natural oils is triglyceride. Also, vegetable oils contain varying amounts of non-glyceride components, which may include impurities such as phosphatides (or phospholipids), sterols, tocopherol, and coloring matter (Waldie., 1968). The triglycerides of naturally fatty acids are colorless. Oils are mixtures of triglycerides with different fatty acids distributed among the triglyceride molecules. R = Fatty acid component Figure 2-1: General chemical structure of triglyceride Fatty acids play an important role in oil properties. Fatty acids can be classified into saturated and unsaturated types. They are low in density, and nearly all are insoluble in water. Examples of common fatty acids found in vegetable oils are stearic acid, palmatic acid, oleic acid, linoleic acid, linolenic acid, pinolenic acid, ricinoleic acid and α-eleostearic acid. In order to classify oils as drying oils, semi-drying oils or non-drying oils, we can use iodine value, that is, grams of iodine required to saturate the double bonds of 100g of oil. An iodine value greater than 140 indicates a drying oil; iodine values between 125 and 140 indicate a semi-drying oil; and a non-drying oil is indicated by an iodine value less than 125 (Austin and Rheineck., 1968). Oil naturally occurs in animal, vegetable and mineral materials. Triglycerides, trimesters of glycerol, and fatty acids make up the largest proportion of the constituents in oils. Natural oils can be categorized into three types based on degree of unsaturation: drying oils such as linseed oil and tung oil, semi-drying oils such as soybean oil, and non-drying oils. Drying oils can be sub-divided into yellowing and non-yellowing oils. Drying oils are obtained mostly from the seeds of vegetables. The properties of drying oils depend largely on their chemical constituents, mainly triglycerides.  2.2 Modified Vegetable Oil Drying oil can be treated or modified by various methods to get certain properties needed for coatings. Bodied oils are used in the manufacture of varnishes, enamels, printing inks, and lithographic varnishes. Bodied oil has high viscosity and better performance characteristics. (Wicks . et al,. 1999). Dehydrated castor oil is conjugated oil which dries relatively rapidly at room temperature. Kraft first dehydrated castor oil in 1877. (Kraft, 1877). The acid catalytic method (Scheiber., 1933) of dehydrating oil is to heat it under a vacuum at a temperature range of 230 to 280oC in the presence of a catalyst until water is no longer evolved. The process for creating maleated oils is by reacting maleic anhydride with conjugated oil or non-conjugated oil via Diels-Alder reaction. (Wicks. et al,. 1999). 2.3 Previous Studies of Reactive Diluents A key to developing high-solid varnish and paint formulations is the development of a reactive diluent which can function as a solvent in the formulation of the coating, but which during the cure process is converted to an integral part of the film. The key characteristic of such materials are low volatility, low toxicity, low odor, and a solubility parameter. Literature review by Satoru et al. in 1978 studied reactive diluents for air-dried alkyd paint. A number of approaches to identification of a suitable reactive-diluent have been described. The chemistry of the vinyl cyclic acetals and their air-drying reactions has been studied by Hochberg. (Hochberg., 1965). Another attractive route to reactive diluents investigated by ICI (Barrett and Lambourne., 1966) should be found in properly designed vinyl monomers, since a whole body of knowledge exists for converting solvent-like vinyl monomers to polymers by a free-radical polymerization process. Unfortunately, the commercial monomers are not fully satisfactory for various reasons including toxicity and high volatility. Bruson (Bruson., 1947) synthesized dicyclopentyl methacrylate from the addition of methacrylic acid to dicyclopentadiene and noted that this ester was converted to a hard insoluble film at ambient temperature. Later on, Donald et al. studied the dicyclopentyl methacrylate as a reactive diluent for high-solid alkyd coatings (Emmons and Larson., 1983). A study by Zabel et al shows design and incorporation of reactive diluents for air-drying high-solid alkyd paints. Zabel et al. described some requirement and design aspects for reactive diluents and also introduced a new class of reactive diluents based on fumarates and succinates of octadienol (OFS) and reported the cure and performance of OFS diluents. Muizebelt et al studied the crosslink mechanisms of high-solids alkyd resins in the presence of reactive diluents via NMR and mass spectroscopy employing model compounds. They found that allyl ether groups appear to react fastest whereas allyl esters show generally little reactivity.  2.4 Alkyd Resins Alkyd resin is the reaction product of polyhydric alcohol and polybasic acids. Alkyds, which can be considered a particular type of polyester, were first proposed by Kienle in 1927. There are two reasons that alkyd resins have become important for coatings. Firstly, alkyds are ultimately versatile and allow choices of structure combination to give tailor-made properties. Secondly, the success of alkyds is due to the relatively low cost. Alkyds can be classified by various criteria. One classification is by oil length based on the ratio of monobasic fatty acid to dibasic acid utilized during synthesis. Another classification of alkyd resins is based on whether they are oxidizing or non-oxidizing type of alkyds. Oxidizing alkyds are comprised of one or more polyols, one or more dibasic acids, and fatty acid derived from one or more drying or semi-drying oils. Non-oxidizing alkyds are used as polymeric plasticizers or as hydroxyl-functional resins and are cross linked with melamine-formaldehyde (MF) resins or urea-formaldehyde (UF) resins. The last classification is modified or unmodified alkyds. Modified alkyds contain other monomers in addition to polyols, polybasic acids, and fatty acids, such as styrenated alkyds and silicone alkyds (Wicks. et al,. 1999). 2.5 Autoxidation Autoxidation is the direct reaction of molecular oxygen with organic compounds under relatively mild conditions (Frankel, 1998). More specifically, autoxidation is described as the insertion of a molecule of oxygen into a C-H bond of a hydrocarbon chain to give an alkyl hydroperoxide (Walters and Am, 1971). Autoxidation and metal-catalyzed autoxidation has been extensively studied for numerous substrates under various reaction conditions Generally, an induction time is observed after which the autoxidation reaction abruptly starts and rapidly attains a limiting, maximum oxidation rate. The reaction proceeds by a free-radical chain mechanism and can be described in terms of initiation, propagation and termination. 2.6 Fatty Acid Autoxidation The fatty acid tail of the alkyd resin is where autoxidation takes place. Fatty acids are important biomolecules, and are present in lipids as their triester with glycerol. Consequently, a considerable amount of research has been performed on elucidation of their autoxidation mechanism, since lipid autoxidation is known to be the cause of vital issues such as food spoilage, tissue injuries and degenerative diseases (Gardner, 1989). The fatty acids in an alkyd resin are polyunsaturated fatty acids, commonly linolenic acid, which is a major constituent of linseed oil (cyberlipid.org) or linoleic acid which is a major constituent of, sunflower oil and soya oil. The high susceptibility of non-conjugated polyunsaturated fatty acids (or lipids) for autoxidation comes from the presence of bis-allylic hydrogen atoms, which have a relatively low bond dissociation energy of 75 kcal/mole and can therefore be easily abstracted, resulting in radical chain initiation and thus autoxidation. Fig 2-2 Bond dissociation energies of the different CH bonds in fatty acids 2.7 Solvents Solvents are substances that are capable of dissolving or dispersing one or more substances. Organic solvents are carbon-based solvents that are used in such products as paints, varnishes, lacquers, adhesives, glues and cleaning agents. A variety of organic compounds and mixtures are used as solvents. Organic compounds can be classified in three broad categories: weak hydrogen-bonding, hydrogen-bond acceptor, and hydrogen-bond donor-acceptor solvents. Weak hydrogen-bonding solvents are aliphatic and aromatic hydrocarbons; commercial aliphatic solvents are mixtures of straight chain, branched chain and alicyclic hydrocarbons. They vary in volatility and solvency. Mineral spirits are slow evaporating aliphatic hydrocarbons. Hydrogen-bond acceptor solvents are esters and ketones. Ketones are generally less expensive than esters with corresponding vapor pressures. Use of methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK) is being reduced because they are on the HAP list. Use of acetone is increasing because it has been delisted and is no longer included as VOC compound by the EPA. Most latex paints contain a slow evaporating, water soluble solvent, such as ethylene or propylene glycol that does not dissolve in the polymer particles. In 1990, the U.S. Congress listed hazardous air pollutants (HAP) for which use are to be reduced (Brezinski, J.J., 1995). Among those of importance in the coatings field are methyl ethyl ketone, methyl isobutyl ketone, n-hexane, toluene, xylene, methyl alcohol, ethylene glycol, and ethers of ethylene glycol. The U.S. EPA’s Hazardous Air Pollutants Strategic Implementation Plan describes regulatory efforts (EPA, 1997). The first step was a voluntary program aimed at reducing emission of 17 chemicals, including toluene, and xylene, by 50% by 1998. Mandatory HAP limits are included in EPA’s Unified Air Toxics Regulations, issued for all major categories of coating users in 1995-1999. Compliance is required within three years of the issue date.  2.8 Atmospheric Photochemical Effects Volatile organic compounds (VOCs) have been recognized to cause serious problems in air pollution. In Europe, solvents are classified by their photochemical ozone creation potential (POCP). Three important end effects of VOC emissions into the atmosphere are: formation of eye irritants, particulates, and toxic oxidants, especially ozone. While all of these factors are important, the most critical for coatings is ozone. Even though ozone is a naturally occurring component of the stratosphere, it is toxic to plants and animals in the troposphere. With the rapid growth of VOC emissions from man-made sources since 1900, ozone levels have exceeded the levels that many plants can withstand and have endangered human health, especially for susceptible individuals. The largest source of man-made VOC emissions is transportation: auto and truck tailpipe emissions, along with fuel leakage during distribution. The second largest source is coatings; in 1995, coatings and adhesives accounted for 11.6% of man-made VOC emissions (EPA, A.U. S., 1990). Photochemical reactions in the atmosphere are complex and dependent on many variables in addition to the amount and structure of VOCs, especially the concentrations of various nitrogen oxides. In early investigations of the effect of VOC on air pollution, organic compounds were divided by rabbit eye irritation tests into photochemical active compounds of high and low reactivity. It was proposed that if the emission of the highly reactive compounds could be limited, the less reactive ones could dissipate and avoid high local concentration of pollutants. This led to the establishment of a definition of photochemically reactive solvents in Rule 66 of the Los Angeles Air Control District. After some year of experience, it was realized that most organic compounds are photo reactive and that the extent of dissipation in the atmosphere after local emission had been overestimated. The coatings industry objected to having to use different solvent combinations in different parts of the country. This situation led to the conclusion that it would be best to limit the emission of almost all organic compounds into the atmosphere  3.0 PROBLEM STATEMENT Nowadays the use of petroleum-based products in manufacturing of different industrial products is facing some serious problems. This is the result of awareness of people to the environmental issues, such as volatile organic compounds (VOC) emissions and recycling or waste disposal problems, spiraling rise in prices and high rate of depletion of the non-renewable stocks. With the rapid growth of VOC emissions from man-made sources since 1990, ozone levels have exceeded the levels that many plants cannot withstand and have endangered human health. The second largest source of man-made VOC emissions is coatings and adhesives which account for 11.6% of man-made VOC emissions. Today researchers are continually attempting to develop “greener” coating systems. Seed-oil based materials are an attractive choice 4.0 JUSTIFICATION Environmental and health hazards cropping up from use of VOCs in varnishes and paint formulations, has demanded for research in alternative reactive diluents. Emphasis is being laid on research pertaining to the modification of VO to introduce novel properties, improved performance coupled with environment friendliness at affordable costs. Vegetable oil is one of the most important renewable raw materials for the chemical industry and is widely used for the surfactants, cosmetic products, and lubricants and also in coatings and paints application. 5.0 Objectives 5.1 Main Objective To formulate a reactive diluent from Croton megalocarpus oil in alkyd coatings. 5.2 Specific Objectives To prepare a reactive diluent from Croton megalocarpus ester by the process of catalyzed esterification of vegetable oil. To determine the physical and chemical properties of the reactive diluent. To formulate an alkyd coating using C. megalocarpus methyl esters. 6.0 HYPOTHESIS Chemically modified Croton megalocarpus seed oil can serve as a reactive diluent in alkyd coatings. 7.0 METHODOLOGY 7.1 Experimental Acid Value and Percentage Free Fatty Acid Determination Three conical flasks were prepared by adding 62.5ml of solvent. The solvent consisted of 50% isopropyl alcohol and 50% toluene. 2.5g Croton megalocarpus oil was added to each of the conical flasks (sample conical flasks). Three other conical flasks were also be prepared, each containing isopropyl alcohol and toluene with no addition of croton oil (blank conical flasks). 2ml of phenolphthalein indicator were added to both the blank and sample conical flasks which were then be titrated with 0.1N KOH to the first persisting permanent pink color. The procedure was done in triplicates. Acid value and fatty acids was calculated from the equation: ACID VALUE = (A+B) ×N ×5.61/ w A=Amount in ml of KOH needed to neutralize sample beaker B=Amount in ml of KOH needed to neutralize blank beakers N= Normality of KOH solution (0.1N) W=Weight of sample in grams (2.5g) Percentage free fatty acid= ½ acid value Viscosity Determination This was measured using an Ostwald type capillary viscometer (viscometer no.38 kusano scientific instrument M.F.G.CO L.T.D) which was immersed in a water bath at 400c. 10ml of oil sample was placed in the viscometer and sucked using a sucker to a marked point on the tube. The time required for the sample to flow down the tube with the help of gravity was determined using a stop watch and this was done in triplicates. The same was repeated for water and the esterified oil. The equation below was used to compute the viscosity Viscosity in centipoises =time take by oil sample to flow down the tube × 0.65 Time take by water to flow down the tube Specific Value Determination Specific gravity or relative density was determined as the ratio of density of the oil to the density of water. A pycnometer was used to measure this. The weight of the pycnometer was determined using an analytical balance, oil was put in the pycnometer and the total weight was determined at 200c. The same was repeated with the esterified oil and water. The specific gravity was computed by the equation: Specific gravity = weight of pyc with oil – weight of empty pyc Weight of pyc with water – weight of empty pyc Saponification Value Determination 5g of the sample oil was weighed accurately into a 250ml conical flask. 50ml of 0.5N alcoholic KOH solution was pipetted into the sample and mixed well by stirring. A blank with all the other reagents present except the oil was prepared. Air condensers were connected to the flasks and boiling in a water bath for at least 30 minutes to completely saponify the sample. After boiling the flasks was left to cool then titrated with 0.5N HCL using phenolphthalein indicator. The endpoints of the blank and sample solutions were. Saponification value was calculated using the formula: Saponification value= (ml of KOH used in blank – ml of KOH used in sample) × 28.05 Weight of sample Ester Value This is a relative measure of the amount of ester present; it is expressed in the same terms as saponification and acid value. It’s obtained by subtracting the acid value from the saponification value Ester value = saponification value –acid value Iodine Value Determination The iodine value was determined using the wijs method. 0.1N sodium thiosulphate was standardized by taking 10ml of 10% KI in a flask and 5ml of concentrated HCl. 25ml of 0.1N K2Cr2O7 was pipetted and the mixture mixed well. 100ml distilled water was also be added in the mixture. Titration was carried out using 0.1N Na2S2O3 and just before the yellow color disappeared a few drops of starch solution were added which changed the color to blue. Titration was then continued until the color changed from blue to green. 5g of the sample was weighed and dissolved 10ml CCl4. A blank solution was prepared. 25ml of the wijs solution was pipetted into the flasks which were stoppered and placed in a dark place for 1 hour. At the end of 30min, 10ml of 30% KI were added followed by 100ml of distilled water to the sample and mixed well. The mixture was titrated with 0.1N Na2S2O3; a few drops of starch solution were added when the color changed to faint yellow. Titration was continued until the blue color disappeared. The same procedure was repeated with the esterified oil. Iodine value = (B-A) ×N (sodium thiosulphate) × 12.69 Weight of oil B= volume of 0.1N Na2S2O3 required for blank (ml) A= volume of 0.1N Na2S2O3 required for sample (ml) 12.69 = number of grams of iodine in 0.1 M Wijs solution  8.0 RESULTS TURBULATIONS AND ANALYSIS 8.1CRUDE OIL PROPERTIES MEASUREMENTS Acid Value and Percentage Free Fatty Acid Determination Table 1: Blank Titration Values 1st TITER 2nd TITER 3rd TITER FINAL READING 10.2 10.3 10.5 INITIAL READING 10.1 10.2 10.4 VOLUME OF KOH USED (Cm3) 0.1 0.1 0.1 Average volume= (0.1+0.1+0.1)/3 =0.1ml Table 2: Croton Oil Titration values 1st TITER 2nd TITER 3rd TITER FINAL READING 10.1 10.0 10.0 INITIAL READING 0.00 0.00 0.00 VOLUME OF KOH USED (Cm3) 10.1 10.0 10.0 Average volume= (10.1+10.0+10.0)/3 = 10ml Acid Value= ((A-B)×0.1N×56.1)/w = (10-0.1) ×0.1×56.1)/2.5 = 22.21 % FFA=0.5(A.V) =0.5(22.21) =11.11 Ref: Korus, A.R, Hoffman, D.S. Ban, N, J. Peterson, CL and Drown, D. C  Viscosity Determination Viscosity in centipoises =53.27 × 0.65 3.01 =11.56 Table 4: time in seconds for determining viscosity Type Time taken by oil(sec) Time taken by water(sec) Viscosity in centipoises Crude oil 53.27 3.01 11.56 Specific Value Determination Specific gravity = weight of pyc with oil – weight of empty pyc Weight of pyc with water – weight of empty pyc Table 5: Weight of empty of pyc Weight of pyc +water Weight of pyc + oil Specific gravity Crude oil 31.4503 53.8713 52.0328 0.919 pH Determination table 6: Type I II III Crude oil 5.3 5.3 5.3 Average= (5.3+5.3+5.3)/3 =5.3 Saponification Value Determination Table 7: Blank titration: Titer 1 2 3 Final volume 40.0 40.0 40.0 Initial volume 0.00 0.00 0.00 Volume of KOH used 40.0 40.0 40.0 Average Volume= (40.0 +40.0+40.0)/3 =40ml Table8: Croton oil titration Titer 1 2 3 Final volume 17.2 34.5 17.3 Initial volume 0.00 17.2 0.00 Volume of KOH used 17.2 17.3 17.3 Average Volume= (17.2+ 17.3+17.3)/3 =17.3ml Saponification value= (40.0 – 17.3) × 28.05 5 = 127.35 Ester value = saponification value –acid value =127.35 - 22.21 =105.14 Ref: Korus, A.R, Hoffman, D.S. Ban, N, J. Peterson, CL and Drown, D. C Iodine Value Determination Table 9: Blank titration: 1 2 Final volume 35.6 35.6 Initial volume 0.00 0.00 Volume of KOH used 35.6 35.6 Average Volume= (35.6+35.6)/2 =35.6ml Table 10: Croton oil titration values Titer 1 2 Final volume 8.5 17.0 Initial volume 0.00 8.5 Volume of KOH used 8.5 8.5 Average Volume= (8.5+8.5)/2 =8.5ml Iodine value = (B-A) ×N(sodium thiosulphate) × 12.69 Weight of oil B= volume of 0.1N Na2S2O3 required for blank (ml) A= volume of 0.1N Na2S2O3 required for sample (ml) 12.69 = number of grams of iodine in 0.1 M Wijs solution Iodine value = (35.6-8.5) ×0.1 × 12.69 5 =6.9g 5g of oil takes up 6.9g of iodine 100g of oil takes up 137.5g of iodine 100 × 6.9 5 =137.5g in 100g oil Ref: Korus, A.R, Hoffman, D.S. Ban, N, J. Peterson, CL and Drown, D. C FTRI ANALYSIS  Table 11: Absorption bands [. ƛmax 1/cm] Functional group (chromophore) Absorption intensity 3336-3467.8 C-H stretching vibration weak 3008.7 C-H stretching vibration moderate 2854.5-2925.8 -CH2-asymmetric and symmetric vibration strong 1745.5 C=O ester stretching vibration strong 1651.0 =C-H stretching vibrations moderate 1458.1 -CH2- shear type vibration moderate 1373.2 -CH3- bending vibration moderate 1164.9 C-O-C symmetric stretching vibration moderate 1097.4 C-O-C antisymmetric stretching vibration weak 723.3 -CH2- plane rocking vibration weak  8.2 TRANSESTERIFICATION PROCESS This was performed in a 5-liter conical flask using the reaction ratio 100ml oil + 24.5ml (excess) methanol +weight of KOH used CALCULATIONS Weight of KOH used= (((%FFA × 0.197) +1)/100) ×weight of oil = 2.68 Weight of oil= 84.23g equivalent to 100ml oil. The KOH catalyst was first weighed and dissolved in methanol in a conical flask containing the oil while shaking vigorously at the start of the reaction until the oil and the methanol blended into one homogenous phase. Shaking was done for 30min and the mixture was poured into a separating funnel and allowed to stand overnight while phase separation occurred. The upper layer yellow in color formed the methyl esters while the lower layer brown in color formed the glycerol. The glycerol was separated from the methyl ester layer. Unreacted excess alcohol was distilled off from the biodiesel ester layer using a rotary vacuum evaporator set at 640c. Figure 2: separation layers after Transesterification Ref: Korus, A.R, Hoffman, D.S. Ban, N, J. Peterson, CL and Drown, D. C  8.3 WASHING Washing was carried out to remove the unreacted catalyst using 500ml glass column, and water representing a quarter the amount of biodiesel being washed was sprayed on top of the column using a wash bottle. Warm water that was boiled at 320c was used for washing. The droplets of water passed through the ester dissolving the KOH and settled at the bottom of the column and were dried off. The washing process was repeated until the purple color of phenolphthalein indicator on the waste water was no longer observed indicating that all the KOH had been washed away. Figure 3: washing process 8.4 PERCENTAGE YIELD This was determined by measuring the amount of biodiesel obtained after reaction as a ratio of the amount reacted. Percentage yield= Amount of methyl ester obtained × 100 Amount of crude oil reacted Percentage yield Croton.m oil 95% Ref: Korus, A.R, Hoffman, D.S. Ban, N, J. Peterson, CL and Drown, D. C 8.5METYL ESTER PROPERTIES MEASUREMENTS Acid Value and Percentage Free Fatty Acid Determination Table 12: Blank Titration Values 1st TITER 2nd TITER 3rd TITER FINAL READING 10.2 10.3 10.5 INITIAL READING 10.1 10.2 10.4 VOLUME OF KOH USED (Cm3) 0.1 0.1 0.1 Average volume= (0.1+0.1+0.1)/3 =0.1ml Table 13: Methyl esters Titration Values 1st TITER 2nd TITER 3rd TITER FINAL READING 0.6 0.6 0.5 INITIAL READING 0.00 0.00 0.00 VOLUME OF KOH USED (CM3) 0.3 0.2 0.2 Average Volume = (0.2+0.2+0.3)/3 = 0.233ml Acid value of Modified Oil ((0.233-0.1) × 0.1 × 56.1)/2.5 =0.2984 % FFA=0.5(A.V) =0.5(0.2984) =0.1492 Ref: Korus, A.R, Hoffman, D.S. Ban, N, J. Peterson, CL and Drown, D. C Viscosity Determination Table 14: time in seconds for determining viscosity Type Time taken by oil (sec) Time taken by water(sec) Viscosity in centipoises Methyl ester 25.74 3.01 5.56 Viscosity in centipoises =25.74 × 0.65 3.01 =5.56 Specific Value Determination Table 15: Weight of empty of pyc Weight of pyc +water Weight of pyc + oil Specific gravity Methyl ester 31.4503 53.8713 51.0687 0.877 pH Determination table 16: Type I II III Crude oil 7.1 7.1 7.1 Average= (7.1+7.1+7.1)/3 =7.1  Saponification Value Determination Table 17: Blank titration: Titer 1 2 3 Final volume 40.0 40.0 40.0 Initial volume 0.00 0.00 0.00 Volume of KOH used 40.0 40.0 40.0 Average Volume= (40.0 +40.0+40.0)/3 =40ml Table 18: Methyl ester titration Titer 1 2 3 Final volume 1.5 2.9 4.4 Initial volume 0.00 1.5 2.9 Volume of KOH used 1.5 1.4 1.5 Average Volume= (1.5+ 1.3+1.5)/3 =1.47ml Saponification value= (40.0 – 1.47) × 28.05 5 = 216.2 Ester value = saponification value –acid value =216.2 - 0.2984 =215.9  Iodine Value Determination Table 19: Blank titration: Titer 1 2 Final volume 35.6 35.6 Initial volume 0.00 0.00 Volume of KOH used 35.6 35.6 Average Volume= (35.6.0+35.6)/3 =35.6ml Table 20: Methyl ester titration values Titer 1 2 Final volume 8.8 17.6 Initial volume 0.00 8.8 Volume of KOH used 8.8 8.8 Average Volume= (8.8+8.8)/2 =8.8ml Iodine value = (B-A) ×N(sodium thiosulphate) × 12.69 Weight of oil B= volume of 0.1N Na2S2O3 required for blank (ml) A= volume of 0.1N Na2S2O3 required for sample (ml) 12.69 = number of grams of iodine in 0.1 M Wijs solution Iodine value = (35.6-8.8) ×0.1 × 12.69 5 =6.8g 5g of oil takes up 6.8g of iodine 100g of oil takes up 136g of iodine 100 × 6.8 5 =136g in 100g oil Ref: Korus, A.R, Hoffman, D.S. Ban, N, J. Peterson, CL and Drown, D. C FTRI ANALYSIS Table 21: Absorption bands [. ƛmax 1/cm] Functional group (chromophore) Absorption intensity 3008.73008.7 3008.7 C-H stretching vibration strong 2854.5-2923.9 -CH2-asymmetric and symmetric vibration strong 1743.5 C=O ester stretching vibration strong 1652.9 =C-H stretching vibrations moderate 1458.1 -CH2- shear type vibration moderate 1373.2 -CH3- bending vibration moderate 1163.0 C-O-C symmetric stretching vibration moderate 1097.4 C-O-C antisymmetric stretching vibration weak 914.2 C-H bending vibration weak 723.3 -CH2- plane rocking vibration weak  9.0 RESULTS ANALYSIS TABLE 22: SUMMARY OF THE ANALYSIS PARAMETER RAW OIL METHYL ESTER ASMT STANDARDS COMMENTS Acid Value 22.21 0.2984 0.3 max Within range % FFA 11.10 0.1492  - - Saponification value  126.95  216.2  ˂200 Slightly higher Ester Value 104.74 215.9 - - Iodine Value  137.5  136.0  133  slightly higher Viscosity in Centistokes @400c  11.50  5.56  4-6 Within range Density @200c 0.919 0.877 0.74-0.95 Within range PH Value  5.3  7.1  6.5-8.0 Within range 10.0 DISCUSSION TRANSESTERIFICATION PROCESS This is the process of exchange of the alkoxy group of an ester compound with an alcohol. Transesterification of croton megalocarpus oil in the presence of a catalyst produces alcohol esters of the oil as glycerol as the by product. The basic reaction is shown below: ACID VALUE AND PERCENTAGE FREE FATTY ACIDS Acid value indicates the proportion of free fatty acid in the oil. The acid value obtained for croton oil was 22.21 mg KOH/g and that of the methyl ester was 0.2984mgKOH/g. This is within the accepted range and this could be as a result of thorough washing to remove any KOH catalyst is methyl ester after reaction. Free fatty acids obtained were 11.11mgKOH/g for the crude oil and 0.1492mgKOH/g for the methyl esters. Higher acid values can be attributed to the presence of fatty acids in the oil which come about during phase separation stage where some soap may have been formed. However, the free fatty acids can be removed by neutralization of the oil with alkali. The resultant methyl esters is dried after washing with water by heating as the presence of moisture facilitates the formation of free fatty acids by hydrolysis. SAPONIFICATION VALUE Saponification value indicates the number of average molecular weight of a fat or oil, it may be defined as the number of milligrams of caustic potash required to neutralize the fatty acids obtained by complete hydrolysis of one gram of oil or fat. Thus saponification values gives information about the proportion of some acid on the oil or fat. Saponification value obtained for croton oil was 127.35 mg KOH/g and that of the methyl ester was 216.2mgKOH/g. This was found to be 8% higher than the acceptable ASTM range. The higher the saponification value the smaller the length of the fatty acid chain. SPECIFIC VALUE Specific gravity obtained for the crude oil was 0.919 while that of the methyl ester was 0.877. A reduction in specific gravity was noted, crude oil reduced after Transesterification from 0.919 to 0.877 which was within the ASTM range. pH VALUE pH obtained for the crude oil was 5.3 while that of the methyl ester was 7.1 at 24.500C. The methyl esters met the range of 6.5-8.0. VISCOSITY The viscosity of the crude oil was 11.56 while that of the methyl ester was 5.56 centistokes. Thus Transesterification reduced the viscosity. Methyl esters as reactive diluents reduce the viscosity in alkyd coatings. The methyl esters satisfied the ASTM rage of 4-6 centistokes. IODINE VALUE Oils are classified according to their film forming ability. Thus they can be classified according to their iodine values. Iodine value is the number of grams of iodine absorbed by 100g of oil. The iodine value of the crude oil was found to be 137.5 while that of the methyl ester was found to be 136 which were 3% higher than the theoretical range of 133. The results show that C.megalocarpus oil is a semi drying oil since semi drying oils have iodine values in the range of 120-150.  11.0 FORMULATION OF VARNISH samples Alkyd resin Solvent Diluent Driers Ant skinning agent Cobalt naphthanate Calcium naphthanate A 100g 50g 0.0 0.6g 1.0g 1.5g B 100g 45g 5g 0.6g 1.0g 1.5g C 100g 40g 10g 0.6g 1.0g 1.5g D 100g 0.0g 50g 0.6g 1.0g 1.5g Table 4: Formulations of different coatings systems used for testing  11.1) RESULTS Samples Viscosity (cP) Drying Time(Hrs) A 1500 8 B 1200 6 C 800 5 1/2 D 465 4  11.2) DISCUSSION The synthesized materials reduced the viscosity of the alkyd on account of the compatibility with the alkyd resin, the lower molecular weight, and additional flexibility compared to an alkyd chain. Formulation D cured faster than formulation A, B and C due to high level of conjugated double bonds present in the fatty acid chains reactive diluents effectively reduced the viscosity and drying time of the coating. Use of reactive diluents in small quantities is sufficient to reach application viscosities of alkyd resins, and eliminate the need for organic solvents in alkyd-based coatings.  12.0) CONCLUSION A reactive diluent from C.megalocarpus was synthesized. All parameters tested to verify the quality of synthesized methyl esters were within the accepted standards as set by the American Standard for Testing Materials (ASTM) Incorporation of the diluents into alkyd-based coatings formulations has shown that the C.megalocarpus methyl esters derivatives acted effectively as reactive diluents 13.0) RECOMMENDATIONS More research should be done to determine the suitability of the reactive diluent obtained Further research should be done to determine other properties on the coating such as density, VOC, impact resistance, hardness, film thickness, flexibility and gloss and weatherability.  REFERENCES Barrett, K.E.J. and R. Lambourne, Air-drying alkyd paints. 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