There are two main kinds of polymers. Type 1: Addition Polymers Each small molecule adds to the end of a growing chain. Polyethylene is an example Type 2: Condensation Polymers Monomer units come together with the elimination of some small molecule (often water). Polyesters and nylons are examples

Condensation Polymers Also called “Step-Growth Polymers” Their synthesis does not involve a chain reaction. Instead any two molecules can react at any time.

Instead any two molecules can react at any time. Each end of the molecule reacts in turn forming dimers, trimers etc.

Nylons - Polyamides Nylon 6 A polyamide

Nylon 66

Nylon 6-10 In the lab

Supramolecular Structure is Important Hydrogen bonds hold the nylon chains together

Kevlar - Helmets - Bullet Proof Vests

Nylon 2 - the simplest protein

There are 20 principle amino acids

Protein - 20 different R groups

Polyesters Dacron

Cross linked

Starch  -glucose Polyether

DNA