1. Polymerization Reactions Chemistry II

2. Types of Polymerization Reactions Addition polymerization – monomers are added together, with no other products formed Condensation polymerization – small molecule, like water, is formed in the polymerization

3. Types of Polymers Copolymer – Two different monomers form the chain Homopolymer – All of the monomers are the same Thermoset– when molded to a certain shape it cannot be softened again or dissolved, like Bakelite Thermoplastic – can be remelted after molded

4. Addition Polymerization Process initiated by free radical (has unpaired electron) Free radical attacks double bond to form a new free radical Termination of the reaction occurs when 2 radicals react to form a bond

5. Condensation Polymerization Formation of Nylon dimer Dimer – two monomers joined Amino group on left or Acid group on right can continue to react, extending the polymer

6. Polymers based on Ethylene LDPE – Low Density Polyethylene – Highly branched – Not tightly packed HDPE – High Density Polyethylene – Mostly straight-chain molecules – Tightly packed

7. Examples Polypropylene – monomer is propylene, so X is CH 3 Isotactic chain vs. Syndiotactic vs. Atactic

8. Polystyrene Polyvinyl chloride (PVC)