Polyvinyl chloride, also known as PVC, is one of the most widely used plastics in the world, with many different applications across various industries. How does nexAir play a role in all of this? The synthesis of PVC involves several chemical processes, those in which acetylene gas plays a critical role. At nexAir, we provide our customers with high-quality, reliable supplies of gases, including acetylene, for their day-to-day tasks. Keep reading as we use our KnowHow and discuss the significance of acetylene and its impact on the synthesis of PVC plastic. 

 

What is acetylene? 

 

Acetylene is a colorless gas that is lighter than atmospheric air. It is a highly reactive gas that can be produced as a by-product of a reaction between water and calcium. It is commonly used in heating processes and is considered the most efficient of all fuel gases in many industries. In the plastics industry, acetylene is utilized with other chemicals and elements such as chlorine and hydrochloric acid to produce different variants such as PVC. Acetylene is extremely valuable to the synthesis of PVC plastic for the reasons discussed, and more. 

 

The Synthesis of PVC Plastic

 

Step 1: Vinyl Chloride Monomer (VCM) Production

 

The first step in PVC synthesis includes the production of vinyl monomer (VCM). Acetylene is a key component in this process. Through a reaction called hydrochlorination, acetylene reacts with hydrogen chloride to form vinyl chloride, the monomer unit of PVC. This reaction takes place at high temperatures and pressures, carried out by catalysts such as cuprous chloride. 

 

Step 2: Polymerization of Vinyl Chloride

 

After the VCM is obtained, it goes through a process called polymerization to form PVC. Polymerization involves the linking of smaller monomer units to form a long-chain polymer. With PVC, the polymerization is primarily achieved through a free radical mechanism. Free radicals, brought about by initiators such as organic peroxides, initiate the reaction and propagate the chain growth. While acetylene is not directly involved in this step, its role in VCM production makes it an important part of this polymerization process. 

 

Key Notes on Controlling PVC Properties 

 

Acetylene’s impact goes way beyond its involvement in the synthesis of PVC. When using acetylene, it is important to be aware of the amount used, while that alone can directly affect the properties of the final PVC product. It is also critical to ensure that there are no impurities in the gas, as those can lead to the formation of polyacetylene, a highly conductive and undesirable material. All in all, it is extremely important to control and minimize the presence of acetylene in the VCM to ensure the desired outcome and characteristics of the PVC. 

 

If you are interested in learning more about acetylene, and its many roles across various industries, please feel free to contact our team. With years of experience, we would be happy to answer any questions that you may have and share our KnowHow, allowing you and your team to continue to Forge Forward in every project that you take on.