Could you please explain the Novolac and Bakelite structure with the diagrams.....?
Novolac Formation: When phenol and formaldehyde are heated in the excess of phenol (P/F > 1) with an acid catalyst, such as HCl, H2SO4 or oxalic acid, a linear polymer is formed which is thermoplastic in nature and is known as Novolac.
Bakelite: On further heating, in the presence of hexamethylene tetramine, Novolac produces 3D cross-linked networked thermosetting polymer which is known as bakelite.