Bakelite

The limitations of celluloid led to the next major advance, known as "phenolic" or "phenol-formaldehyde" plastics.  A chemist named Leo Hendrik Baekelund, a Belgian-born American living in New York state, was searching for an insulating shellac to coat wires in electric motors and generators. Baekelund found that mixtures of phenol (C6H5OH) and formaldehyde (HCOH) formed a sticky mass when mixed together and heated, and the mass became extremely hard if allowed to cool and dry.

He continued his investigations and found that the material could be mixed with wood flour, asbestos, or slate dust to create "composite" materials with different properties.  Most of these compositions were strong and fire-resistant.  The only problem was that the material tended to foam during synthesis, and the resulting product was of unacceptable quality.

Baekelund built pressure vessels to force out the bubbles and provide a smooth, uniform product.  He publicly announced his discovery in 1909, naming it "bakelite."  It was originally used for electrical and mechanical parts, finally coming into widespread use in consumer goods in the 1920s.

Bakelite was the first true plastic.  It was a purely synthetic material, not based on any material or even molecule found in nature.  It was also the first "thermoset" plastic.  Conventional "thermoplastics" can be molded and then melted again, but thermoset plastics form bonds between polymer strands when "cured," creating a tangled matrix that cannot be undone without destroying the plastic.  Thermoplastics are tough and temperature resistant.

Bakelite was cheap, strong, and durable.  It was molded into thousands of forms, such as radios, telephones, clocks, jewelry, buttons, lamps, and, of course, billiard balls.

Phenolic plastics are still in widespread use.  For example, electronic circuit boards are made of sheets of paper or cloth impregnated with phenolic resin.

Many bakelite items are now collectors items.  Here are a few tips for bakelite collectors.  There are some simple ways to tell if an item is truly made of bakelite.  The first is smell.  Rub the item briskly with your fingers until it is warm.  You should get a formaldehyde or carbolic acid smell.  Once you are familiar with the smell, it is fairly recognizable.  Another method calls for placing "Scrubbing Bubbles" bathroom cleaner on a q-tip and touching it to the bakelite - the q tip should turn yellow.  And, yes, bakelite colors do change as they age.

Some interesting bakelite sites: The Bakelite Museum, Columbia Encyclopedia

Plastic Polymers  |  Celluloid & Rayon  |  Bakelite  |  Polystyrene & PVC  |  Nylon   Synthetic Rubber  |  A Plastics Explosion  |  Plastic Recycling  |  Packaging Products