1. Introduction

Bakelite is the first synthetic thermosetting polymer discovered by Leo Baekeland in 1907. It is a phenol-formaldehyde resin formed by condensation of phenol (C₆H₅OH) with formaldehyde (CH₂O). Bakelite is known for its hardness, heat resistance, electrical insulation, and chemical stability.

General formula: (C₆H₄OCH₂)_n

2. Types of Phenol-Formaldehyde Resins

• Novolac: Acid-catalyzed condensation, linear polymer with free phenolic –OH groups. Requires a hardener (hexamethylenetetramine) for curing.
• Resole: Base-catalyzed condensation, self-curing polymer (thermosetting), can be molded under heat and pressure.

3. Preparation of Bakelite

Monomers: Phenol (C₆H₅OH) + Formaldehyde (CH₂O)

Step 1: Prepolymer Formation

Condensation reaction (acid/base catalyzed) forms a viscous prepolymer (Novolac or Resole), with water elimination.

Step 2: Molding

Prepolymer is heated under pressure to form a thermosetting network, giving a hard, infusible, and insoluble Bakelite.

4. Properties

• Mechanical: Hard, rigid, and brittle
• Thermal: High heat resistance; does not melt
• Electrical: Excellent insulator
• Chemical: Resistant to water, acids, and alcohols
• Processability: Can be molded into various shapes under heat and pressure

7. Applications

• Electrical: switches, plugs, sockets, insulating components
• Kitchenware: handles, knobs, trays
• Industrial: bearings, gears, mechanical parts
• Consumer products: jewelry, buttons, decorative items