What happens when phenol reacts with formaldehyde?
One reacts phenol and formaldehyde directly to produce a thermosetting network polymer, while the other restricts the formaldehyde to produce a prepolymer known as novolac which can be moulded and then cured with the addition of more formaldehyde and heat.
What is the structure of phenol formaldehyde?
Phenol-formaldehyde resin
| PubChem CID | 24754 |
|---|---|
| Structure | Find Similar Structures |
| Chemical Safety | Laboratory Chemical Safety Summary (LCSS) Datasheet |
| Molecular Formula | C8H6O2 |
| Synonyms | Phenol-formaldehyde resin Phenolic resin Phenol, polymer with formaldehyde Formaldehyde phenol polymer Formaldehyde, phenol polymer More… |
What are the properties of phenol formaldehyde?
Properties of Phenolic Resins In addition, phenol formaldehyde resin properties include good thermal insulation, low density and excellent durability. They are easy to mold into a variety of shapes and complex contours, making them adaptable to custom equipment or environments.
What happens when phenol reacts with formaldehyde in presence of sodium hydroxide?
The negative change attached to phenol ring by deprotonation of phenol would activate otho and para substituent sites of Phenol to polymerize with methanal (formaldehyde); Or perhaps some unreacted Formaldehyde with Sodium hydroxide may undergo Cannizzaro disproportionation reaction to form sodium methanoate and …
What is the ratio of phenol to formaldehyde to produce bakelite polymer?
Novolac is prepared when (P/F) (phenol/formaldehyde) ratio is greater than 1, whereas bakelite is prepared when (P/F) ratio is less than 1.
How much time is taken for the formation of phenol-formaldehyde?
Formaldehyde addition takes 3 hrs and during that time vacuum reflux is maintained to keep the reaction temperature at 90° C. and to remove water continuously as an azeotrope with xylene.
What is phenolic sheet?
Phenolic sheet is a hard, dense material made by applying heat and pressure to layers of paper or glass cloth impregnated with synthetic resin. These layers of laminations are usually of cellulose paper, cotton fabrics, synthetic yarn fabrics, glass fabrics or unwoven fabrics.
What is the Colour of phenol formaldehyde?
Chemical Classification: Phenol Formaldehyde Resin(Novolac) Colour: Pale Amber.
What is the ratio of phenol to formaldehyde to produce Bakelite polymer?
How much time is taken for the formation of phenol formaldehyde?
What is the ratio of urea formaldehyde to produce useful resins?
The ratio of urea to formaldehyde is between 1:2 and 1:2.2 and therefore methylolation can take place at in a short amount of time at temperatures between 90 and 95 °C, with a mixture being maintained under reflux. The formation of the resin is completed after the exotherm has subsided.
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