Question

Napoleon’s Buttons– Chapter 8 – Isoprene

1. What is rubber chemically?

2. What part does sis-trans isomerism play in rubber?

3. What is the significance of the trans isomeric “isoprene”?

4. What makes rubber stretch?

5. What is the significance of the disulfide link? What is the process called?

6. How did the history of rubber lead to the discovery of polystyrene?

Answer 1

1. Rubber is polyisoprene

2. They can't be packed tightly with another sis isomer. Crystallization becomes difficult

3. The transiomers can be tightly packed. Crystallization becomes easier.

4. Cross linkng between polymers make rubber stretch

5. Covalent bond between two thiol grouds. This is called as disulfilde shuffling. This is also called as S-S bond.

6. In 922, Staudinger mentioned that natural rubbers were made up of long repetitive chains of monomers that gave rubber its elasticity. He also stated that materials manufactured by thermal porocessing of styrene was similar to rubber. They were the high polymers which include polystyrene as well.