Q. With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements:

  1. Its fibres can be blended with wool and cotton fibres to reinforce their properties.
  2. Containers made of it can be used to store any alcoholic beverage.
  3. Bottles made of it can be recycled into other products.
  4. Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions.

Which of the statements given above are correct?

  • 1 and 3
  • 2 and 4
  • 1 and 4
  • 2 and 3

Answer: (a) 1 and 3

Notes:

  • Polyethylene terephthalate is a condensation polymer of ethylene glycol and terephthalic acid.
  • It is a thermoplastic synthetic substance, malleable under heat, and can be placed into nearly any shape known mostly for its short PET form.
  • Terephthalate polyethylene (PET) is very moisture tolerant.
  • Polyethylene terephthalate has outstanding chemical resistance to organic matter and water, it is not biodegradable.
  • A list of uses of polyethylene terephthalate is given below.
    • For the manufacturing of shopping bags, water bottles, videotapes, containers and bags, clothes and housing material, water bottles, microwave containers, packaging films, etc.
    • Polyester for fabrics is strong and flexible, and when combined with materials like cotton can reduce wrinkling, and shrinking, and makes the fabric more resistant to tears.
  • Advantages of Polyethylene terephthalate
    • It is readily available and relatively inexpensive.
    • It has a high strength-to-weight ratio.
    • It is very resistant to moisture.
    • It has excellent chemical resistance to organic material and water (it is not biodegradable which is good and bad depending on your perspective and its intended use).
    • It is virtually shatterproof (it won’t break like glass packaging).
    • It is easily recycled.
    • It can be reused by conducting a series of washing processes or broken down into its constituent raw materials which can then be turned into the original resin.
    • It is highly transparent.
  • PET consists only of carbon, hydrogen, and oxygen, so if it is burned in the air (or in pure oxygen), the combustion products will be carbon dioxide and water.