2. Preparation of phenolic resin
Phenolic resin is also known as phenolphthalein resin, tincture agent rubber, is a room temperature curing type phenolic resin, phenol and formaldehyde under the catalysis of barium hydroxide condensation polymerization reaction, obtained by dehydration under reduced pressure.
First, formula
Normal > raw material name
Normal > molar ratio
Normal > purity /%
Normal > dosage / mass
Normal > phenol
Normal > formaldehyde solution
Normal > Barium hydroxide
Normal > 1
Normal > 1.25
Normal > 98
Normal > 37
Normal > 100
Normal > 106
Normal > 2 ( dissolved in 5 times water )
Normal > Barium Hydroxide Molecular Formula Ba(OH)2 · 8H2O is easily weathered into barium carbonate (white powder)
Barium hydroxide formula Ba(OH)2·8H2O is easily weathered into barium carbonate (white powder) before use
First, the process method
(1) Add the melted phenol to the reaction vessel (the laboratory can use a three-necked bottle), start the stirring, and increase the temperature by 40-450C to add cesium hydroxide.
(2) Heat up to 65~750C within 30min, hold for 10~20min until the barium hydroxide is completely dissolved.
(3) Add formaldehyde solution, heat up to 850C within 20~30min, stop stirring, boil due to exotherm, temperature reaches 97~1000C, boil and return for 10 min and then stir.
(4) Keep reflux for about 60 minutes and then measure the turbidity temperature. When it reaches 40~500C, cool the water immediately.
(5) When
