A polymer is a macromolecular material having a large number of repeating units linked to each other via covalent chemical bonds. PVC and bakelite are two important polymer materials.
What is PVC?
PVC is a polymer consisting of polyvinyl chloride. It is a thermoplastic polymer made of chloroethene monomers. PVC is a very common polymer. There are two groups of PVC as the rigid form and the flexible form. The rigid PVC material is important in construction needs, whereas the flexible PVC form is used for wiring and cables.
There are three major steps in the production of PVC. The first step involves the conversion of ethane into 1,2-dichloroethane. This step is performed via chlorination. The second step of PVC production is cracking of 1,2-dichloroethane into chloroethene, along with the elimination of an HCl molecule. The third and final step of PVC production is the polymerization process of chloroethene in order to produce PVC via the free radical polymerization process.
PVC has several notable properties, including high hardness and beneficial machinery properties, poor heat stability, good flame retardancy, high electrical insulation, and chemical resistance. Moreover, there are many benefits to using PVC. For example, it is readily available in the market, and it’s a cheap material with good tensile strength. Besides, this material is also resistant to chemicals such as acids and bases.
What is Bakelite?
Bakelite is the first plastic made from synthetic components. Bakelite is a thermosetting phenol–formaldehyde resin. This substance is formed from the condensation reaction of phenol and formaldehyde. The material was discovered and developed by the chemist Leo Baekeland, and it was patented in 1909. This discovery was revolutionary because it made many different and important applications in many areas.
When considering the production of bakelite, it is a multistep process that begins with the heating of phenol and formaldehyde in the presence of a catalyst. Typically, HCl, zinc chloride, or ammonia base are used as the catalyst here. This reaction forms a liquid condensation product named Bakelite A. It is soluble in alcohol, acetone, and phenol. Upon further heating, this liquid tends to become partially soluble and becomes an insoluble hard gum. When using high temperatures for this production, it can produce foam. The innovative discovery of Bakeland was putting the last condensation product into an egg-shaped Bakelizer that can suppress the foaming, which results in a substance that is extremely hard, infusible and insoluble.
There are many important properties of bakelite. For example, we can mold this material quickly, and it has a decreased production time. Moreover, these molding are very smooth and can retain their shape. Also, the material is resistant to electricity, heat, scratches, and solvents.
What is the Difference Between PVC and Bakelite?
PVC and bakelite are polymer materials. The key difference between PVC and bakelite is that PVC is a thermoplastic material, whereas bakelite is a thermosetting material. Moreover, PVC is made from polyvinyl chloride, while bakelite is made from phenol-formaldehyde resin. So, this is another difference between PVC and bakelite. PVC production involves chlorination of ethane, elimination of HCl during the cracking step and polymerization of chloroethane, while Bakelite involves heating of phenol and formaldehyde in the presence of a catalyst.
Below is a summary of the differences between PVC and bakelite in tabular form.
Summary – PVC vs Bakelite
Although both PVC and bakelite are polymer materials, they differ from each other based on their chemical and physical properties. The key difference between PVC and bakelite is that PVC is a thermoplastic material, whereas bakelite is a thermosetting material.
1. Johnson, Todd. “PVC Plastics: Polyvinyl Chloride.” ThoughtCo, Aug. 28, 2020, thoughtco.com/what-is-pvc-plastics-820366.
1. “Polyvinylchlorid” By NEUROtiker – Own work (Public Domain) via Commons Wikimedia
1. “3-D Structure of Bakelite” By JohnSRoberts99 – File:Bakelit Struktur.png by MarkusZi (GFDL) via Commons Wikimedia