Chapter 27, Problem 42P

Interpretation Introduction

Interpretation:

The structures of repeating units when acrolein undergoes anionic polymerization should be determined.

Concept Introduction:

Polymers:

Monomers combine together to form polymers. Monomers are the repeating units of small molecules which link together to form polymers and the process is called as polymerization.

Two types of polymers:

• Synthetic and biopolymers.
• DNA is an example for biopolymer and these type of polymers are synthesized by cells.
• Polymers synthesized by scientists are called synthetic polymers and some examples are nylon, polyester etc.

Two types of synthetic polymers:

• Chain-growth polymers or addition polymers and step-growth polymers or Condensation polymers.
• Chain growth polymers are formed by the monomer addition to the end of a growing chain.
• Step-growth polymers are formed by combining monomers by removing small molecules of water or alcohol.

Anionic polymerization:

• Initiator will be a nucleophile which reacts with the monomer to form a propagating site that is an anion and the initiator can be compounds like sodium amide or butyllithium.
• Nucleophile will attack on the alkene and the alkene contain a substituent that can withdraw electrons by resonance.