Plastics before Bakelite
Before Bakelite, people already used materials that could be shaped and set. Natural shellac, horn, tortoiseshell and gutta-percha were molded for combs, buttons and small objects. In the 1860s, Alexander Parkes in Britain showed Parkesine, a cellulose-based material, and John Wesley Hyatt in the United States developed celluloid, which became popular for collars, combs and billiard-ball substitutes.
These were semi-synthetic, because they started with cellulose from plant fiber that was chemically modified. Celluloid was also flammable and softened with heat. A material made wholly from simple chemicals, which stayed rigid once formed, was still missing.
Leo Baekeland’s work
Leo Baekeland was born in Belgium and moved to the United States in the 1890s. He had already earned money from a photographic printing paper that he sold to a large photographic company, which gave him the freedom to build a private laboratory. He then turned to reactions between phenol and formaldehyde, which chemists such as Adolf von Baeyer had noticed in the 1870s produced a sticky resinous mass that seemed useless and hard to clean from glassware.
Baekeland’s insight was less the discovery of the reaction than learning to control it. Through experiments around 1907, he found that careful control of temperature and pressure, with the right proportions and a catalyst, could produce a hard, infusible solid. He filed patents in 1907 and announced the material publicly in 1909. Other chemists were working on similar resins at the same time, and patent arguments followed, so the credit for first making a phenolic resin is not as simple as popular accounts suggest. What is well documented is that Baekeland turned it into a commercial product.
Thermoset versus thermoplastic
Bakelite is a thermosetting plastic. During manufacture, the molecules link together into a rigid three-dimensional network, so reheating the finished piece does not melt it. That differs from a thermoplastic such as celluloid or most modern bags and bottles, which soften again when heated and can be remelted.
This property gave Bakelite its main uses. It resisted heat, did not conduct electricity and held its shape, so it suited electrical insulators, switches and sockets. It could also be mixed with fillers such as wood flour or cotton fabric to make it tougher and cheaper.
Making it: the Bakelizer and molding
Baekeland built a pressure vessel, called the Bakelizer, in which the resin could be cured under heat and pressure to avoid bubbles. A key factory step was compression molding. Powder or partly reacted resin mixed with filler was placed in a heated steel mold, pressed, and the piece hardened in the mold. After a few minutes it could be removed and trimmed.
General Bakelite Company was formed in 1910, and a merger in the early 1920s created the Bakelite Corporation. Mold making became a skilled trade of its own. Because steel molds were expensive, the product suited long runs of identical parts, which linked the material closely to mass production.
Where it showed up
By the 1920s and 1930s, Bakelite turned up in many places:
- Telephone handsets and housings.
- Radio cabinets, as radio broadcasting became a household habit.
- Electrical plugs, switches and distributor caps for cars.
- Cameras, pens, clocks and kitchen handles.
- Jewelry and decorative items, often in a cast form with brighter colors.
Early articles were typically dark brown or black, since the resin and fillers darkened. Cast phenolic resins later allowed marbled and brighter colors, and they are now collected. Designers found the material suited streamlined, rounded shapes. Among electric kitchen appliances, handles and knobs made of molded resin were a common use because they stayed cool and did not conduct current.
Competitors and successors
Bakelite’s patents expired in the late 1920s, and competitors began selling similar phenolic resins. Meanwhile, chemists expanded the range of plastics. Urea-formaldehyde resins offered lighter colors. In the 1920s, Hermann Staudinger argued that plastics and rubber were long-chain molecules, called macromolecules, an idea that was disputed at first but was widely accepted by the 1930s and helped guide later work. Polystyrene, PVC and nylon followed, and the petrochemical industry later supplied cheap raw materials for synthetic fibers and other polymers. Bakelite gradually lost ground to lighter and easier-to-mold thermoplastics, although phenolic resins still appear in laminates, brake linings and electrical parts.
Why it matters
Bakelite is often called the first fully synthetic plastic, and that is a fair description if taken to mean a commercially successful one made from simple chemicals rather than modified natural polymers. Its importance lies partly in the material and partly in the business around it: standard molds, shaped consumer goods and the idea that a chemist could design a material to order. Concerns about disposal and recycling came much later, since thermoset plastics are harder to reuse than thermoplastics.