Question

What is the difference between elastomers and fibres? Illustrate with an example of each.

Answer 1

Elastomers: Elastomers are polymers in which the weakest intermolecular forces hold the polymeric chains together. The elastomers can be stretched because of extremely weak intermolecular forces. These polymers are made up of polymer chains that are coiled at random. The polymer is stretched when a force is applied, opening up the randomly coiled chains. A few cross-links are typically added between the polymer chains to aid in the polymer’s ability to retract to its initial position upon the release of the applied force.

Fibres: The polymers consisting of strong intermolecular forces between the polymeric chains are called fibres. One important example of this kind of polymer is nylon-66, a polyamide. Hydrogen bonds hold the polymeric chains in this polymer together. Both its modulus and tensile strength are very high. Strong dipole-dipole interactions between the polymeric chains that make up polyesters (like terylene, dacron, etc.) and polyacrylonitriles (like orlon, acrilan, etc.) make them significant fibers as well.