How will you prepare Bakelite from phenol?
Basically it is formed in two steps. In the first step formaldehyde reacts with phenol and produces o-Hydroxymethyl phenol. Then o-Hydroxy methyl phenol and phenol come together and form Bakelite. The reaction is condensation polymerisation as two molecules condense and give out by-product.
What is the process for making Bakelite?
Making Bakelite is a multi-stage process. It begins with heating of phenol and formaldehyde in the presence of a catalyst such as hydrochloric acid, zinc chloride, or the base ammonia. This creates a liquid condensation product, referred to as Bakelite A, which is soluble in alcohol, acetone, or additional phenol.
How is Bakelite prepared in laboratory?
Bakelite is the commercial name for the polymer obtained by the polymerization of phenol and formaldehyde. These are one of the oldest polymers that were synthesized by man. Phenol is made to react with formaldehyde.
Is phenolic the same as Bakelite?
Bakelite is the trade name of one particular phenol-formaldehyde resin formulation, to which wood powder or other materials was usually added as a filler. These materials are generically called phenolic resins. Bakelite was invented by a Belgian chemist who emigrated to the US, Dr. Leo Baekeland.
What is Bakelite and how it is prepared from phenol?
Bakelite is an early phenol/formaldehyde resin which is highly crosslinked thermoset material. It is produced through condensation reaction between phenol and formaldehyde in the presence of either basic or acidic catalyst. It was developed by the Belgian-American chemist Leo Baekeland in New York in 1907.
What is the ratio of phenol and aldehyde in Bakelite polymer?
Base-catalysed phenol-formaldehyde resins are made with a formaldehyde to phenol ratio of greater than one (usually around 1.5).
Which of the following compound is used in preparation of Bakelite?
Phenol and formaldehyde are used in the manufacture of Bakelite polymer.
How would you obtain phenol from aniline?
How to prepare phenol from aniline?
- Aniline is diazotized by treatment with nitrous acid (NaNO2 and HCl) under ice-cold conditions to form benzene diazonium chloride.
- The step is followed by hydrolysis with dilute sulphuric acid to form phenol.
Why was Bakelite discontinued?
Bakelite applications in conservation were discontinued in the 1940s because of certain disadvantages that soon became apparent. The lack of records and relevant information precludes any assumption on the extent of its use and in which institutions.
Is Bakelite still used today?
Bakelite still has some of its classic applications in automotive and electrical products. But the material also is used in space shuttles, Harp said.
Which compound is used in preparation of Bakelite?
A hard, infusible, and chemically resistant plastic, Bakelite was based on a chemical combination of phenol and formaldehyde (phenol-formaldehyde resin), two compounds that were derived from coal tar and wood alcohol (methanol), respectively, at that time.
How do you make Bakelite plastic?
- Mix the phenol and formaldehyde in a pressure vessel to form a resin.
- Pour the resulting resin in a mold, either the shape of the finished item or a block of Bakelite that can be cut, carved and polished.
- Harden the resin under high temperature and pressure, in excess of 160 degrees Centigrade.
How to prepare Bakelite from phenol?
The Bakelite preparation can be demonstrated in the following steps of reactions- Combination of phenol and formaldehyde to form ortho and para hydroxy benzyl alcohols. Formation of Novalac from ortho hydroxy benzyl alcohol. Water molecule is removed in the process.
Is Bakelite a condensation polymer or a phenolic resin?
It is a thermosetting phenol-formaldehyde resin formed by the condensation reaction of phenol with formaldehyde. So, we can, in general, say that Bakelite is a condensation polymer or a phenolic resin.
How do you make Bakelite?
The preparation of bakelite involves several steps, as illustrated below. Initial methods of preparing bakelite involved the heating of formaldehyde and phenol in the presence of one of the following catalysts -zinc chloride (ZnCl 2 ), hydrochloric acid (HCl), or ammonia (NH 3 ).
What are the fillers added to Bakelite resin?
Asbestos, wood flour, cotton flock, cotton pulp, gypsum, mica etc., are a few reinforcing fillers that are added in molding resins like Bakelite. Following are a few properties that are enhanced by the addition of fillers: