What is application of phenol-formaldehyde resin?
Used as the basis for Bakelite, PFs were the first commercial synthetic resins (plastics). They have been widely used for the production of molded products including billiard balls, laboratory countertops, and as coatings and adhesives.
How do you dissolve phenol-formaldehyde resin?
phenolic resin is a brittle polymers and have good thermal properties due to the presence of aromatic structure in their polymers chain, So in order to degradation with out using heat y using strong solution of sodium hydroxide.
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.
Is phenol resin toxic?
Phenolic resin has low toxicity. For their excellent mechanical resistance, high heat resistance under load, and high impact resistance, phenolic resins are used in structural composite materials.
Why phenol formaldehyde resin is colored?
Depending on the relative amounts of the reactants and the nature of the catalyst, the reaction produces either novolacs or resols resins. Their color depends on the type of catalyst used in production and ranges from light yellow to reddish. However, do not forget the effect of phenol and phenol type as well.
How does phenol and formaldehyde resins work together?
A cyclic urea prepolymer in phenol/formaldehyde resins acts as a plasticizer for the resin. This makes the laminate more post-formable and tougher. Products produced with such resins resist chipping and breakage during machining steps.
What makes a novolak a phenol formaldehyde resin?
Segment of a novolak, illustrating the predominance of cresol subunits and presence of crosslinking. Novolaks (or novolacs) are phenol-formaldehyde resins with a formaldehyde to phenol molar ratio of less than one. In place of phenol itself, they are often produced from cresols (methylphenols).
Which is the first synthetic form of formaldehyde?
Phenol formaldehyde resin (plastic) was the first commercial polymers used in the 20th century. We abbreviate the Phenol formaldehyde resin as PF. It is also known as the phenolic resin, one of the first synthetic polymers that we can obtain by the reaction of phenol or substituted phenol with formaldehyde.
What are the trade names for phenolic resin?
Trade names Bakelite is made from phenolic resin and wood flour. Novotext is cotton fibre-reinforced phenolic, using randomly oriented fibres. Oasis is “an open-celled phenolic foam that readily absorbs water and is used as a base for flower arrangements.”.