Overview Of PVC

Overview of PVC

PVC belongs to one of the five major commodity thermoplastics that is widely consumed. Its demand in the market has been increasing rapidly for years because of its versatility and superior properties, while being cheap at the same time. In 2012, PVC consumption was 54 million, and had experienced an increase of 9 million since 2009.[1] As seen in Figure 1, PVC is used in many applications, such as pipes, window profiles, rigid films, etc.

Figure 1 - Applications of PVC[1]

Figure 2 – Predicted increase in consumption for various polymers[2]

Based on Figure 2, we can observe that the consumption of PVC is expected to double by the time we approach 2025. This would imply that the applications of PVC are increasing as well. However, this also means that the amount of PVC waste generated would also increase by two times. Hence, it is important that we look into ways to recycle PVC.

Chemical Structure and Properties

Figure 3 – Chemical structure of PVC

PVC is a hydrocarbon that contains chlorine atoms; hence it is a polar polymer. It is popular because of its self-extinguishing property. When it is heated, chlorine gas in released. Chlorine gas starves the fire from oxygen and immediately extinguishes the fire. PVC has a unique property, whereby it is impossible to melt it fully without degrading it.

80% of the PVC consumed are produced by suspension polymerization[3]. It is produced by adding initiator, monomer and suspending agent. It is important that we control the temperature during polymerization because the process is exothermic. Other methods of producing PVC include emulsion polymerization and bulk polymerization. It is important to note that the morphology that is formed by the polymerization proc...

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