The Epoxy Equivalent Weight and Epoxy resin have characterized the weight of the resin epoxy group.
1. APPARATUS
- Magnetic Stirrer
- Graduated Pipette
- Graduated Burette
- Measuring cylinder
- Erlenmeyer Flasks
- Analytical Weighing Balance
2. REAGENTS
- 0.1 N HBRÂ Solution
- Glacial Acetic Acid
- MIBK (Methyl isobutyl ketone)
- Crystal Violet Indicator
3. PROCEDURE
1. Weigh approx 0.4 gms of Epoxy Resin in an Erlenmeyer flask.
2. Now add 10 ml of MIBK and mix well.
3. Now add 10 ml of glacial acetic acid and mix properly.
4. Titrate with 0.1 N HBR Solution using only one drop of Crystal Violet indicator till a sea green color appears.
Calculation of epoxy equivalent weight
EPOXY EQUIVALENT =Â (Â Sample
weight x Non Volatile Matter x 1000 /
                    ML of HBR solution
used x Normality of HBR x 100
EPOXY VALUEÂ =ML of HBR solution used x
Normality of HBR/
                    Sample
weight of Epoxy Resin
5. PRECAUTIONS:
Use proper PPE (gloves,
masks, and goggles) before handling the reagents and Titration.
All sample preparations
should be done in a well-ventilated area.
HBR should be prepared fresh because its strength varies with aging (not more than 7 days).
Determination of Potlife of Polyols and Modified Acrylic polyolÂ
Pot life of epoxy resin and paint chemicals resin polyols testing methods.
APPARATUS:
 a) 500 ml Glass Beakers
 b) Ford Cup B-4
c) Plastic Covers to cover
Beakers
d) Rubber Bands
 e) glass rod
Reagents & Solutions
 Part-A:- (Solvent Part)
Acrylic Resin - 55.5
 For example- Acrylic Resin, Polyoles etc.
Orthoxylene - 13.0
Butyl Acetate - 10.0
BYK-306(10%)Â - 1.00Â [BYK-306
(10 Part) + Orthoxylene (90Part)]
Modaflow 2100(1%)Â - 1.00 [Modaflow 2100 (1 Part) + Orthoxylene (99Part)]
Part-B:- (75% Hardner Part)
Desmodur N-75 - 75.0
Orthoxylene - 15.0
Butyl Acetate - 10.0
SOFTNER:-
Orthoxylene - 50%
Butyl Acetate - 50%
POT LIFEÂ PROCEDURE:
Mix Part (A + B) in 4: 1
ratio.
The viscosity of 4: 1 mixture
should be 18-20 sec.
If viscosity is higher than 20 sec, then it is diluted with SOFTNER, till viscosity reaches 18 – 20 sec. Check the viscosity of the mixture in the B-4 cup and note the time. Check the viscosity at the interval of every half an hour. When viscosity reaches double of the initial viscosity i.e. 40 secs note down the time. This time difference between the initial time and the final time is the POT LIFE.
PRECAUTIONS:- Cover the beakers of the solvent mixture after every check of Viscosity.
SPECIFICATIONS: Minimum 3:00 HOURS
>TESTING METHODÂ OF HYDROLYZABLE CHLORIDE CONTENT OF LIQUID EPOXY RESINS
