JEE Main · 2021 · 16 Mar 2021 · Shift 2 · Polymers

A wood laminate is held together by a thermosetting adhesive that cures in the hot press into a rigid cross-linked network and bonds well to the hydroxyl-rich cellulose surface. Urea and formaldehyde condense to exactly such a resin, cheap and nearly colourless, and it is the standard binder for plywood and laminated sheets. Natural rubber is an elastomer and never sets, phenol-formaldehyde resin goes into moulded electrical fittings and handles, and melamine-formaldehyde resin is reserved for unbreakable crockery. The polymer used in the manufacture of wood laminates is urea-formaldehyde resin.