Problem 117 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following is a fully fluorinated polymer? (a) Neoprene (b) Teflon (c) Thiokol (d) \(\mathrm{PVC}\)

Step-by-Step Solution

Answer

Teflon (b) is the fully fluorinated polymer.

Step 1: Understand the Term 'Fully Fluorinated Polymer'

A fully fluorinated polymer is a polymer where all the hydrogen atoms are replaced with fluorine atoms. This replacement results in a polymer that is highly resistant to chemicals and temperature, typically possessing a low coefficient of friction.

Step 2: Analyze Option (a) Neoprene

Neoprene, also known as polychloroprene, is a polymer that contains chlorine atoms and is not fluorinated at all. Therefore, it cannot be considered a fully fluorinated polymer.

Step 3: Analyze Option (b) Teflon

Teflon is the brand name for polytetrafluoroethylene (PTFE), which is indeed a fully fluorinated polymer. In PTFE, all hydrogen atoms are replaced by fluorine, making it a classic example of such a polymer.

Step 4: Analyze Option (c) Thiokol

Thiokol is a trade name for a group of polymers utilized in rubber products, often containing sulfur and is not fully fluorinated. Thus, this option is incorrect.

Step 5: Analyze Option (d) PVC

PVC, or polyvinyl chloride, contains chlorine atoms and no fluorine. It is not a fluorinated polymer, much less a fully fluorinated one.

Step 6: Conclusion

By evaluating each option, we determine that Teflon (option b) is the only polymer among the choices that is fully fluorinated.

Key Concepts

Polymer Chemistry

In the world of polymer chemistry, understanding the structure and composition of polymers is essential. Polymers are large molecules made of repeating subunits known as monomers. These can be natural, like rubber and silk, or synthetic, such as nylon and PVC. The properties of a polymer largely depend on its chemical structure.
In particular, the presence of different atoms can drastically alter the characteristics of the polymer. When hydrogen atoms in the polymer chain are replaced with fluorine atoms, the polymer becomes a fluorinated polymer, known for its distinct traits and adaptability.

• Highly stable
• Resistant to heat and chemicals
• Often has low friction

Teflon is a famous example of a fully fluorinated polymer. Its comprehensive replacement of hydrogen with fluorine gives it unique properties that are beneficial in numerous applications, from non-stick cookware to industrial machinery.

Chemical Resistance

Chemical resistance is an intrinsic property of polymers, playing a crucial role in determining their suitability for various applications. This property allows a polymer to withstand aggressive substances without undergoing degradation or loss of integrity.
Fluorinated polymers, such as Teflon, exhibit exceptional chemical resistance. The bond between carbon and fluorine in these polymers is one of the strongest in organic chemistry.

• Highly resistant to solvents
• Low reactivity with most chemicals
• Stable in corrosive environments

These attributes make fluorinated polymers ideal for use in situations where exposure to harsh gases, liquids, or temperatures is anticipated.
Given these benefits, fully fluorinated polymers are extensively utilized in fields like chemical processing, where maintaining material integrity in corrosive environments is paramount.

Polymer Analysis

Polymer analysis is a vital process in the development and application of polymers in various industries. Through analysis, scientists and engineers determine the composition, structure, and properties of polymers to better understand their performance and potential uses.
Several techniques are utilized in polymer analysis, including but not limited to:

• Spectroscopy, to investigate molecular composition and structure
• Chromatography, for separating polymer mixtures
• Thermal analysis, to study thermal stability and transitions

For fluorinated polymers, these methods are especially helpful in confirming the degree of fluorination, analyzing thermal stability, and assessing chemical resistance. Such information is crucial in ensuring that the polymer meets the necessary specifications for its intended application.