Abstract- Oil-modified alkyd rosin was prepared from petroleum Castor oil. The experiment started with look intoing the optimal conditions for neutralisation of petroleum Castor oil and bleaching of neutralised oil.
Then the features ( iodine value, viscousness, acerb value, refractile index and colour ) of oils were determined. Refined oil has iodine value of 90, kinemetic viscousness of 4 St, free fatso acid value of 1, refractile index of 1.474 and colour figure of 8. These consequences showed that the refined oil was qualified to fix dehydrated Castor oil. Dehydration of refined oil was carried out at 210-220EsC under 600-640mmHg with the aid of 1 % ( wt % ) NaHSO4 accelerator. The dehydrated Castor oils were analyzed for I value, viscousness and its set to touch clip and drying clip were besides investigated. Dehydrated Castor oil has iodine value of 140, kinemetic viscousness of 1.
6 St, set to touch clip of 4 hour and drying clip of 5 yearss. And so, oil modified alkyd rosin ( acerb value 6.6 ) was prepared from dehydrated Castor oil by alcoholysis method in surplus of glycerin and phthalic anhydride in the presence of 0.3 % ( wt % ) NaOH accelerator. The obtained rosin was characterized by Fourier Transform Infrared Spectrophotometer ( FTIR ) and the belongingss were determined.Keywords- Alcoholysis method, Alkyd rosin, Castor oil, Dehydrated Castor oil, Polymerization
Polymerization is one of the most of import industrial procedures.
Resins and emulsion are two chief categories of polymer. Alkyd rosins are by far the most of import category of surfacing rosins. It is estimated that alkyd rosins contribute about 70 % to the conventional binders used in surface coating today. The popularity of alcoholic rosins as vehicle for coatings is mostly due to their alone belongingss such as movie hardness, lastingness rubric and rubric keeping, opposition to scratch, etc. impacted on them through alteration with drying oil [ 1 ] .Alkyd rosins are used in both clear and pigmented, industrial and trade coating to protect and adorn a broad assortment of substances. The industrial coatings or coatings by and large are applied during the fabricating procedure of the point which they cover. Often they are specifically formulated to run into both conditions desired for their application and the eternal usage of the article of industry.
The industrial coatings include primers and top coats for iceboxs, furniture, and electrical equipment. In position of the development of these points and sectors, the positive growing is expected for pigment industry [ 2 ] .Further the pigment industry envisages a future enlargement in position of development in Automobile Industry, public-service corporation in Nuclear Power Station, development in Corrosion Resistant Coatings, enlargement in lodging activity and other industry uses. The demand of alkyd rosin being an ingredient in Paint, Varnish and Printing ink industry would be linked with the Paint industry.There are many important attempts that have been made to increase alkyd rosin production. Many research workers have attempted to seek the different beginnings for alkyd rosin readying. Airegumen I Aigbodion et Al [ 3 ] studied heightening the quality of alkyd rosins utilizing methyl esters of gum elastic seed oil in 2004.A batch of alkyd rosins were imported to Myanmar Paint Industries every twelvemonth.
In order to salvage foreign currency outflow, it is needed to bring forth alkyd rosin in Myanmar.The oils that are largely employed for alkyd rosin synthesis are linseed oil, soya bean oil, dehydrated Castor oil, fish oil and tall oil. Myanmar being rich in aquatic and tellurian resources, every province and division is prosecuting the mark of seting 500,000 estates under physic nut ( castor oil ) in three old ages. Rural development undertakings are included in the national development enterprises that are being carried out by the Nation mark.Castor oil is utile straight in protective coatings as a plasticiser in alkyd systems, and blown Castor oil is an of import nitrocellulose plasticiser. In commercial industry of dehydrated Castor oil, the purpose is to bring forth the most valuable stuff for usage as a drying oil. By far the most of import coatings usage of Castor oil is in the signifier of dehydrated Castor. Dehydrated Castor oil is now recognized as an single drying oil with its ain characteristic belongingss and advantages.
The drying oils owe their value as natural stuffs for cosmetic and protective coatings to their ability to polymerise or “ dry ” after they have been applied to a surface to organize tough, adherent, imperviable, and scratch opposition movies. The advantages claimed in surface coating applications include first-class olfactory property and heat bleachability, good drying belongingss, more unvarying polymer construction, and deficiency of after-yellowing. The dehydrated Castor oil is non-yellowing oil and so this can give demands of surfacing industries [ 2,4,5,6,7 ] .
II. MATERIALS AND METHODS
Neutralization of Crude Castor Oil
Oil ( 100g ) was heated to 55EsC. Then, the deliberate sum of strong ( 45EsBe, 2N NaOH ) lye was added to neutralize the free fatty acids precisely, with changeless stirring. Completion of neutralisation reaction was determined by proving the mixture with phenolphthalein index.
When the index colour of the sample mixture turned to tap, neutralisation was completed. Then, NaCl solution was heated to 90EsC and 20ml of hot NaCl solution was added to the mixture to guarantee equal salting or graining out of soapstock. After that the mixture was poured into dividing funnel. Three hours subsequently, the mixture was separated into two distinguishable beds. Then the lower bed or soap bed was drain out.
The upper bed or oil bed was washed with hot H2O. Washing was carried out until colour of phenolphthalein index did non alter to tap. After complete lavation, the oil was dried at 100EsC in oven to vaporize the wet. Drying and chilling was carried out until the weight of dried oil remained unchanged.
The neutralised oils were weighed to cipher oil loss and so their free fatty acid content ( FFA ) were determined [ 8 ] . The features of rough oil and neutralised oil were determined by American Society of Testing and Materials ( ASTM ) criterion methods.
Bleaching of Neutralized Oil
The neutralised oils were heated to 100EsC and different sums of activated wood coal were added. After the mixture was stirred for 45 proceedingss, the mixture was cooled to room temperature and activated wood coal was removed by filtrating with filter paper.The neutralised oils were besides bleached with different sums of bentonite and a mixture of activated wood coal and bentonite ( 1:1 ratio ) . Then the procedure was carried out above process.The colourss of faded oil samples were determined by a spectrophotometric method [ 11 ] .
In this method, optical densenesss were measured at the wavelength of 460nm, 550nm, 620nm and 670nm. Then the photometric colourss were calculated by the undermentioned equation.Photometric colour = 1.29D460 + 69.7D550 + 41.
2D650 -56.4D670 [ 4 ]
Dehydration of Castor Oil
Bleached oil ( 50g ) and 2 % ( wt % ) of NaHSO4 accelerator were placed into unit of ammunition underside flask and the setup was set up. The system was heated to 210-220EsC for desiccation clip were taken for 15, 30, 45, 60, 75 proceedingss.Dehydration was besides carried out under 600-640 mmHg ( vacuity ) as described in the above procedure. In this procedure, the consequence of NaHSO4 accelerator sum on the belongingss of dehydrated Castor oil was besides investigated.
Then, the I values of dehydrated Castor oil were determined by ASTM D1541-86 and viscousnesss were determined by ASTM D 1545-63 method. The drying clip and set to touch clip were besides determined by ASTM D 1953-70 [ 9 ] .
Preparation of Alkyd Resin
Oil modified alkyd rosin was prepared with dehydrated Castor oil, glycerin and phthalic anhydride utilizing NaOH accelerator. The readying was done in a 4-neck unit of ammunition underside flask fitted with a motorised scaremonger, a nitrogen recess, a thermometer pocked and a clasp for trying. In the readying of alkyd rosin, two phases were involved. The first phase was alcoholysis phase and the 2nd phase was esterification phase.
Phase 1 ( alcoholysis ) : In this phase, monoglyceride was foremost prepared by responding the oil with glycerin. Alcoholysis of oil was carried out with different per centums of ( 0.03 % , 0.05 % , 0.1 % ) ( by weight ) PbO accelerator and ( 0.1 % , 0.
2 % , 0.3 % ) ( by weight ) NaOH accelerators.In alcoholysis reaction, the oil was heated with agitation velocity of ( 700 revolutions per minute ) and N2 sparging rate of about ( 0.06ft3/sec ) to 230-240EsC. Glycerol and selected accelerator was added and alcoholysis reaction was carried out at 230-240EsC.
The reaction was continued until a sample of the reaction mixture became soluble in two to four volumes of anhydrous methyl alcohol. After alcoholysis reaction was completed, the reaction mixture was cooled to 140EsC.Phase 2 ( esterification ) : In this phase, phthalic anhydride was added to the monoglyceride mixture.
The temperature was maintained at the scope of 230-240EsC and maintained at this temperature. The sparging rate of N2 was increased to ( 0.1ft3/sec ) . The reaction was monitored by periodic finding of the acerb value of the mixture until acerb value dropped to about 5.The acerb value of alkyd rosin was determined by ASTM D 1639-90 and the chemical oppositions besides determined. The prepared rosin was standardized by FTIR [ 12, 13 ] .
RESULTS AND DISCUSSIONS
Word picture of Crude Castor Oil
The features of petroleum Castor oil are shown in Table 1.Table 1. The Characteristics of Crude Castor OilFeaturesCrude Castor oilFree fatso acid value19Color, photometric
Specific gravitation0.9633Viscosity ( Stroke )4.5Iodine value, wiji ‘s89.5
Neutralization of Crude Castor Oil
Table 2 show the FFA content of neutralised oil.Table 2.
The FFA Content of Neutralized OilInitial weight of petroleum Castor oil = 100gFFA ( % ) of petroleum oil = 19 %Neutralization temperature = 55EsC20 % NaCL solution = 40mlSr.no2N NaOH( milliliter )Neutralization clip ( proceedingss )FFA ( % )of Neutralized oilWeight of Neutralized oil ( g )115.258.44865.09230100.98760.43330100.98851.
Word picture of Refined Castor Oil
The features of refined Castor oil are described inTable 3 by comparing with ASTM standard Castor oil.Table 3.Characteristics of Refined Castor OilFeaturesRefined Castor oilCastor oil( ASTM D 960-79 )Free fatso acid value11.00Color, photometric8
476 to 1.4778Specific gravitation0.96140.957 to 0.961Viscosity ( Stroke )46.
3 to 8.9Iodine value, wiji ‘s9083 to 88
Bleaching of Neutralized Castor Oil
Consequence of decoloring on colour and output of neutralised Castor oil is shown in Table 4. Oil was bleached with 0-11 % of activated C, 0-9 % of bentonite and 0-7 % of 1:1 mixture of activated wood coal and bentoniteTable 4. Consequence of Bleaching On Color and Yield of Neutralized Castor OilInitial weight of neutralised oil = 100 gBleaching temperature = 100EsCBleaching clip = 45 proceedingssSr. no.Bleaching agents( wt % ) of decoloring agentPhotometric colour number*Wt.
of Refined oil ( g )A1A2A3A4A5Activated wood coal ( A )3579117.256.357.168.
217B1B2B3B4Bentonite ( B )35793.803.404.404.
311C1C2C3Activated wood coal and bentonite ( 1:1 ratio ) ( C )3574.03.04.4657.40557.34257.
254*Photometric colour = 1.29D460 + 69.7D620 + 41.
2D650 a?’ 56.4D670 [ 4 ] .
Dehydration of Refined Castor Oil
Table 5 present the output of dehydrated Castor oil at different desiccation conditions. The alterations of I value and viscousness by desiccation of Castor oil at different desiccation conditions are shown in Fig. 1 and Fig. 2.Table 5.
Output of Dehydrated Castor Oil at Different Dehydration ConditionsInitial weight of sample C2 = 50gNaHSO4catalyst ( % )V.P( mmHg )Dehydration clip ( proceedingss ) /Yield ( % )153045607527600.590.3789.8889.5689.
P-vacuum force per unit areaFig. 1.Change of Iodine Value with Reaction Timefor Dehydration Temperature at 210-220EsCFig. 2. Change of Viscosity with Reaction Timefor Dehydration Temperature at 210-220EsC
Word picture of Dehydrated Castor Oils
The features of typical dehydrated Castor are presented in Table 6 by comparing with ASTM criterion dehydrated Castor oil.Table 6.Characteristics of Typical Dehydrated Castor OilsVacuum force per unit area = 600-640 mmHgFeaturesDehydrated Castor oil1Dehydrated Castor oil 2Standard dehydrated Castor oilIodine value140.01139.
05125-145Viscosity ( Stroke )1.6001.6861.5-1.8Set to touch clip ( hr )43.52.5, aboutDrying clip ( hr )55
1dehydration with 1 % NaHSO4 accelerator for 60 proceedingss2dehydration with 2 % NaHSO4 accelerator for 45 proceedingss
Preparation of Alkyd Resin
Reaction status of alcoholysis reaction status in alkyd rosin readying is described in Table 7.
Fig. 3 shows the acerb value control of esterification reaction. Output of dehydrated Castor oil-modified alkyd rosin and the computation for per centum of reaction complection are presented in Table 3.8.Table 3.7. 1st Stage Alcoholysis Reaction ConditionsReaction temperature = 230-240EsCAgitation speed = 500 revolutions per minuteN2 sparging rate = 0.06 ft3/minutesAlcoholysis acceleratorsCatalyst % ( wt % )Chemical reaction clip ( hour )Completion of alcoholysis reaction*PbO0.
034Not complete0.054Not complete0.14Not completeNaOH0.14Not complete0.24Not complete0.32complete*It was determined by proving the solubility of alcoholysis mixture in anhydrous methyl alcohol.Fig. 3.
Acid Value Control of Esterification ReactionTable 8. Output of Dehydrated Castor Oil-Modified Alkyd ResinDCO alkyd rosin ( 100 % solid )I..W ( g )F.W( g )Yttrium
( % )
( % )
5886.697.72I.W-initial weightF.W-final weightY-yieldIAV-initial acid valueFVA-final acid valueP-degree of reaction complection
Word picture of Alkyd Resin
The physico-chemical belongingss of alkyd rosin are presented in Table 9. The chemical oppositions of alkyd rosin movie are shown in Table 10. Table 11 show FTIR soaking up set of dehydrated Castor oil-modified alkyd rosin.Table 9.
Features of Dehydrated Castor Oil-modified Alkyd ResinPropertiesDCO alkyd rosinRSO alkyd resin*DCO alkyd resinwAcid value6.612.74-11Iodine value80.2466.3
RSO- gum elastic seed oilBeginning [ 1, 14 ]Table 10. Chemical Resistances of Alkyd Resin FilmsMediaSubmergence clip ( hours )Appearance of film*Distilled H2O18Not consequence3 N NaOH8Whitening16Blistering24Removal*It was examined after the movies were air dried for 30 proceedingss.
Table 11. FTIR Absorption Band of Dehydrated Castor Oil-Modified Alkyd ResinBand No.Experimental frequence( cm-1 )Literature frequence( cm-1 )Remark123453008.992926.743514.211169.212855.
301125.26Near 30303570-3200Near 11002926-28501485-14401750-17351730-17171150-1060=C-HO-HO-HC-HCH2CooCH3COOCH3O=C-O-C-
Harmonizing to Table 1 FFA content of petroleum Castor oil was high and it was non within the ASTM specification bound. The lone ground to cut down the FFA content of oil was to neutralize the petroleum oil.In neutralisation procedure, it was found that 30 milliliter of 2 N NaOH per 100g of oil was required to obtain neutralised oil with an acceptable FFA content and to be a lower limit of oil loss. The neutralisation clip of 10 proceedingss was sufficient to cut down FFA content from 19 % to 1 % . The two beds can be easy separated when NaCL solution was added to the neutralised mixture because NaCL can assist to guarantee equal salting or graining out of the soapstock. Other drosss in oil were removed by rinsing with hot H2O.From Table 3, it can be seen that the neutralisation procedure can cut down the FFA content of rough oil from 19 % to 1 % .
Then, it can give the refined oil colour of 8 and refractile index of 1.474. Therefore, neutralisation procedure can offer great consequence on FFA content, colour and refractile index of oil.In Table 4, it can be seen that the highest colour remotion efficiency was obtained by decoloring with 5 % of decoloring agents. Bleaching with ( 1:1 ) mixture of activated wood coal and bentonite can offer better consequence. So, it can be chosen as decoloring agents in bleaching of neutralised oil.Harmonizing to the Table 5, the output of dehydrated Castor oil decreased with increasing the desiccation clip. In Fig.
1 and 2, it was observed that the dehydrated Castor oil with a maximal I value and a minimal viscousness could be obtained at the proper reaction clip. From Fig. 1, the desiccation of oil without vacuity system could non give acceptable I value to measure up as drying oil. When desiccation of oil was done by utilizing 2 % of accelerator and vacuity force per unit area of 600-640 mmHg and the optimal reaction clip is 45 proceedingss, this system could give the dehydrated Castor oil with iodine value of 139.05.Table 7 described that the I value and viscousness of dehydrated Castor oils were in the bound of ASTM criterion dehydrated Castor oil.
Harmonizing to the literature [ 3 ] , the alcoholysis reaction is normally completed within an hour or two hour after the batch had reached operating temperature. In Table 8, it was found that the samples of the alcoholysis mixture did non wholly soluble in anhydrous methyl alcohols although the alcoholysis reactions were carried out for 4 hour by utilizing different sum of litharge accelerators ( 0.03 % , 0.
05 % , 0.1 % ) and NaOH accelerators ( 0.1 % , 0.2 % ) .
In alcoholysis of oil with 0.1 % ( wt % ) and 0.2 % ( wt % ) NaOH accelerator, it can non besides give complete alcoholysis mixture after reaction was carried out for 2 hour.In esterification reaction, it was observed that the longer the reaction clip, the more syrupy the mixture is. In Fig. 3.3, the oil-modified alkyd rosin with acerb figure of 6.
6 was obtained after the esterification reaction was carried out for 150 proceedingss. In Table 8, it was observed that 97.72 % of reaction was completed when the concluding acid figure of alkyd rosin was 6.6.
The alkyd rosin that has acid figure of less than 15 is suited for application of pigment, harmonizing to literature [ 1, 7, 8 ] .Table 10 described that there was no consequence on alkyd movie after submergence in distilled H2O for 18 hours. The submergence of alkyd movie in H2O for 18 hours was sufficient clip to analyze the H2O opposition. When the alkyd movie was immersed in strong alkali solution, 3N NaOH, the movie got whitening after submergence clip for 8 hours, vesicating after submergence clip for 16 hours and remotion after submergence clip for 24 hours. So, these consequences show that the prepared alkyd rosin has high chemical opposition.The FTIR spectrum of prepared alkyd rosin exhibits a feature of heterosexual concatenation ester set at 1738.
64 cm-1 and aromatic ring ester set at 1730.09 cm-1. The present of O=C-O-C- besides exhibit a characteristic ester set at 1125.
26 cm-1. The visual aspect of CH2, -CH- confirms the nowadays of methyl group at 1460.43 cm-1 and 2856.
67 cm-1. The surface assimilation set at 3008.99 cm-1 is characteristic of alkene C ( =C-H ) harmonizing to literature [ 12, 13 ] .
The features of refined Castor oils were found to be standardized with ASTM standard Castor oils and it was suited to transport out the following measure. The refined Castor oil was done by utilizing NaHSO4 accelerator to transport out the desiccation procedure. Dehydration under vacuity force per unit area system was effectual processing method and this force per unit area influenced the quality of dehydrated Castor oil.
A typical dehydrated Castor oil ( iodine value 140, viscousness 1.6 shot, set to touch clip 3.5 hour and drying clip 5 twenty-four hours ) was prepared with 1 % NaHSO4 accelerator under vacuity of 600-640 mmHg at 210-220EsC. In alcoholysis of oil by utilizing 0.3 % ( wt % ) NaOH accelerator, it gave complete alcoholohysis mixture to preceed the esterification reaction after reaction clip for 2 hour. Dehydrated Castor oil has been used in the readying alkyd rosin. Dehydrated Castor oil-modified alkyd rosin ( acerb value 6.
6 ) was prepared by alcoholysis method from dehydrated Castor oil, glycerin and phthalic anhydride with a aid of 0.3 % NaOH accelerator. The physico-chemical belongingss and high chemical opposition of alkyd rosin movie showed that they were assuring in formulating of pigment.