Question

Correct statements among (I) to (IV) regarding silicones are :
I. They are polymers with hydrophobic character.
II. They are biocompatible.
III. In general, they have high thermal stability and high dielectric strength.
IV. Usually, they are resistant to oxidation and used as greases.

• A. I and II only
• B. I, II, III only
• C. I, II, III and IV
• D. I, II and IV only

Answer 1

The correct option is C I, II, III and IV

Silicones are polysiloxanes with general chemical formula, $[R_{2}SiO{]}_n,$ where R is an organic group such as:
$-C{H}_3,-C_2{H}_5,-C_6{H}_5$ etc.

Some of the useful properties of silicones are given below:

1. They repel water (hydrophobic in nature) and form water tight seals.
2. Silicones are biocompatible because these do not support microbiological growth and these have high gas permeability at room temperature.
3. They have in general high thermal stability and high dielectric strength and resistance to oxidation and chemicals.
4. Silicone grease is typically used as a lubricant for brake components in automobiles, since it is stable at high temperature, is not water soluble and is a odorless viscous liquid.