WHAT IS THERMOPLASTIC PVC

What is thermoplastic PVC?  First let's discuss thermoplastics and then specific details about PVC.

Thermoplastics

Plastics can be categorized as either thermosetting or thermoplastic.  Polyvinyl chloride (PVC) is considered a thermoplastic.  Thermoplastics become moldable above a specific temperature and then return back to a solid when cooled.  They can be melted again and again.  Thermoplastics are known for their high molecular weight because intermolecular interactions increase as the plastic is cooled.  In comparison, thermosetting polymers form irreversible chemical bonds as they are cured and therefore they break down when heated and will not re-form as the temperature is cooled.  They can not be heated again and again.

Properties of PVC

Thermoplastic PVC is made of 57% chlorine and 43% carbon.  The chlorine is manufactured by the electrolysis of sodium chloride (salt) and the carbon originates from oil.  PVC is resistant to acids and bases.  It is lightweight and durable and rigid PVC is often used in the construction industry.  Examples include vinyl siding, gutters, and drainpipes.  PVC and also be made in flexible forms by adding a plasticizer which is an additive to increase fluidity (often phthalates are used).  Flexible PVC is used in hoses, tubing, and electrical insulation.

Advantages of PVC

PVC is less dependent on crude oil or natural gas, which are nonrenewable, than other common plastics (PE, PP, and PS).  In addition PVC is fire resistant due to the chlorine component making it an ideal construction component.  The excellent electrical insulation of PVC makes it well-suited for use in cabling.  PVC doesn't corrode, is chemically stable (won't de-polymerize) and has a high impact strength.