3 and 5 are addition polymers :

Addition polymers form :

When unsaturated carbon (organic) molecules react to form a long chain polymer molecule

No small molecules or atoms are eliminated during the reaction chloroethene (vinyl chloride) CH₂ = CHCl monomer forms polymer polyvinyl chloride (PVC) – [ –CH₂ – CHCl – ]_n– (Tetrafluoroethene (tetrafluoroethylene)

CF₂ = CF₂ monomer forms polymer polytetrafluorethene (polytetrafluoroethylene, teflon) – [CF₂ – CF₂ –]_n –

Condensation polymers form :

When bifunctional monomers react to form a long chain polymer molecule small molecules, such as water, are eliminated during the reaction. Polyesters, polyamides, proteins and polysaccharides such as cellulose, are all examples of condensation polymers.

Example : terephthalic acid + ethylene glycol gives polyethylene terephthalate (PET, PETE, or terylene or dacron)

nHOOC – C₆H₄ – COOH + nHO – (CH₂)₂ – OH →

–[–OCC₆H₄ – COO – (CH₂)₂ – O –) _n + (2n – 1)H₂O