Discussion – elasticity
Elasticity of an object depends on the objects ability to resume its normal shape after being stretched or compressed. Elasticity is one of Nylons physical property and its elasticity depends on the techniques on how the nylon has been made. For this experiment using the condensation polymerization, both samples A and B where polymerize using different techniques. For sample A after adding solution A and solution B together, it was left undisturbed to allow the interface between the two solutions. For sample B, it was disturbed when adding the solution together by stirring it vigorously and the polyamide was formed instantly.

Comparing both samples in terms of their elasticity, sample A is much more elastic than sample B. Sample A can be stretched without breaking and at least shrink back again but sample B rarely cannot. As sample B was stretched, it broke apart and did not retain its original form. Furthermore, sample A is much more flexible than sample B. It is easily stretched apart while sample B is a bit hard and not flexible enough. As shown in the picture below, we can clearly see the difference between the two polymers relating to their elasticity. The reason why sample A has better elasticity than sample B is because the interface between the two solutions A and B were not disturbed. This is to avoid both reactants of forming polymer clump in the unstirred interfacial polymerization. Whereas sample B when stirred, it causes the polymers to clump together and as a result causing it to have a higher crystallinity. Higher crystallinity means that the polymers are packed closely to each other that made it hard, not flexible and less elastic. Sample A had a lower crystallinity or more amorphous region than sample B. The higher the crystallinity of the polymer, the weaker the elasticity of the polymer. A higher crystallinity polymer would be less elastic compared to a low crystallinity polymer. Therefore, the higher crystalline polymer will not have any space for the polymer to stretch or extend. While for a low crystallinity polymer there’s more amorphous region since it is not packed closely to each other giving the polymer more space to stretch or being elastic. The elasticity of a polymer depends on how high or low the crystallinity of the polymer is (Wunderlich, 2005).

Wunderlich, B., 2005. Thermal Analysis of Polymeric Materials. [e-book]. Available at: http://books.google.com.my/books?id=dIDe4ZT87BcC&dq=explanation+of+elasticity+of+polymers&source=gbs_navlinks_s [Accessed 5 July 2015].