APPENDIX A
Characterization of plasticizers (epoxidized soybean oil)
a. Acid value
Reagents are 95% ethanol, 0.01 N alcoholic KOH and indicator is 1% phenolphthalein in ethanol
 Alcoholic potassium hydroxide (0.5 N KOH in methanol)
Procedure
Weigh accurately about 5 g of the sample in a dry conical flask. Dissolve the sample in 50 ml
95% ethanol. Add 2-3 drops of 1% phenolphthalein indicator and titrate against 0.01N alcoholic
potassium hydroxide. The end point is indicated by a permanent pink color. Carry out blank as
well.
Acid value = 56.11 ∗
(V2 −V1 )∗N
m
Where, V1 - Titration of alcoholic KOH required for blank, ml
V2 - Titre of alcoholic KOH required for sample, ml
N - Normality of alcoholic KOH
m - Weight of the sample, g
b. Determination of refractive index (RI)
The property value of refractive index of soybean oil and epoxidized soybean oil at 20.0oC was
measured by using a device mettler toledo.
c. Determination of oxirane oxygen content(OOC) using hydrogen chloride (HCl) in acetic
acid by direct titration
Oxirane oxygen content is the method for determining the number of groups of oxiranes
contained in epoxidized soybean oil which can be titrated directly with hydrogen chloride in
acetic acid using AOCS official method Cd 9-57 (1997).
The equation for the approximate content is:
Oxirane oxygen content (OOC) =
Vol.of HCl x M HCl
W
……………………………………………
Where, Vol. HCl = volume of the HCl-acetic acid required for titration (ml)
N HCl = Normality of the HCl solution used for titration (N)
W = sample weight (gram)
Reagents were: Acetic acid-glacial (99.5%), analytical reagent grade, chloro-benzene - analytical
reagent grade, HCl- laboratory grade reagent (3M).
Procedure:
Weigh accurately a sample of 0.3 to 0.6 gram in a 50-ml Erlenmeyer flask. Dissolve epoxy resins
in chloro-benzene, other compounds in chloro-benzene. Add 5 drops of 0.1% crystal violet
indicator solution, place the rubber stopper in position, and lower the burets tip to a point just
above the solution. Titration of the sample to the blue-green end point while stirring at a slow
speed with the magnetic stirrer was performed.
Calculations
1. Acid value calculation
Acid value = 56.11 ∗
(V2 −V1 )∗N
m
2. Oxirane oxygen content calculation
Dilution of HCl in acetic acid:
Molarity of HCl = 3M, Required molarity of HCl= 0.1M, required volume of HCl =?
M1V1 = M2 V2  V1= M2V2/M1 = (0.1M*250ml)/3M = 8.33ml volume of HCl required for
0.1M Preparation.
Oxirane oxygen content (OOC) =
250 ml x 0.1M
10g
= 2.5%
Results table
S.No.
Properties
1
Iodine value
2
Acid value (mg/KOH)
3
Viscosity (pa.s) @ 35 oC
Ostwald method
Refractive index (Mettler Toledo) @20.0 oC
Oxirane oxygen content
(OOC) in %
Conversion, yield
4
5
6
Virgin soybean oil
Property value
0.1269
Epoxidized soybean oil
Property value
0.06345
0.0386
1.4746
1.4840
-
2.5
-
-
-
-