UPSC Prelims 2022 Question:
With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements:
- Its fibres can be blended with wool and cotton fibres to reinforce their properties.
- Containers made of it can be used to store any alcoholic beverage.
- Bottles made of it can be recycled into other products.
- Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions.
Which of the statements given above are correct?
a) 1 and 3
b) 2 and 4
c) 1 and 4
d) 2 and 3
Correct Answer: Option a) 1 and 3
Learn more about Polyethylene Terephthalate in the given explanation below.
Explanation:
Polyethylene terephthalate (PET) is the predominant polyester used for fibre production. They are often used in durable-press blends with other fibres such as rayon, wool, and cotton, reinforcing the inherent properties of those fibres while contributing to the ability of the fabric to recover from wrinkling. So, statement 1 is correct.
Features of PET
- Particularly for highly concentrated spirits in small PET bottles and high storage temperatures the water permeation is unfavourable. In fact, the leaching effects of plastic and plastic chemical substances (such as ethylene glycol) have the tendency to leach considerably into alcohol stored if the temperature goes up during storage. So, statement 2 is not correct.
- PET bottles can be recycled back into bottles, fibres, film, thermoformed packaging and strapping. So, statement 3 is correct.
- The burning of plastics releases toxic gases like dioxins, furans, mercury and polychlorinated biphenyls (better known as BCPs) into the atmosphere, and poses a threat to vegetation, and human and animal health. So, statement 4 is not correct.
- High strength: PET is a very strong material, with a tensile strength of up to 70 MPa. This makes it ideal for applications where strength and durability are required, such as food and beverage packaging.
- Lightweight: PET is a lightweight material, with a density of only 1.38 g/cm³. This makes it an attractive material for packaging applications, as it can help to reduce transportation costs.
- Good chemical resistance: PET has good resistance to a wide range of chemicals, including acids, bases, and solvents.This makes it suitable for packaging a variety of products, including food and beverages, pharmaceuticals, and personal care products.
- Good barrier properties: PET has good barrier properties against gases and liquids, such as oxygen, carbon dioxide, and water. This makes it ideal for packaging products that need to be protected from spoilage.
Therefore, option (a) is the correct answer.
To request a counselling call, please fill out this form: