Give two points of difference between thermoplastics and thermosetting polymers.

The difference between thermoplastics and thermosetting polymers is as follows: Thermoplastics Polymers Thermosetting polymers 1 . These are formed by addition polymerization. 1 . These are formed by condensation polymerization. Thermoplastics Polymers Thermosetting polymers 2 . These soften and melt on heating and harden again on cooling. 2 . These do not soften on heating but rather become hard. On prolonged heating, these start burning.

How does the presence of double bonds in rubber molecules influence their structure and reactivity?

The presence of double bonds in rubber molecules influence their structure and reactivity because cis-configuration about double bonds do not allow the chains to come closer for effective attraction due to weak intermolecular attractions. Hence, the natural rubber has a coiled structure and shows elasticity.