Reactions

Polymers A compound of a high molecular mass made up of a series of monomer units Important compounds Used for multitude applications –Any you can think of? –Natural Polymers DNA, RNA, Starches, Proteins, Enzymes –Synthetic Polystyrene, Polyvinyl Chloride

Chain Growth Polymers Compounds formed by the addition of identical monomer units Monomer is often an alkene A radical initiator is usually present

General Example N is in the hundreds or thousands L is a substituent that determines the type of monomer

Monomer Examples Ethene (ethylene) –Polyethylene Propene (propylene) –Polypropylene

Monomer Examples Styrene –Polystyrene Chloroethene (vinyl chloride) –Polyvinyl Chloride

Types of Plastic Plastic containers have numbers that tell you the type of plastic (1-7) #1 PET Polyethylene terephthalate (Soda) #2 HDPE High-density polyethylene (Milk) #3 PVC Polyvinyl chloride (Pipes) #4 LDPE Low-density polyethylene (Bags) #5 PP Polypropylene (Butter Containers) #6 PS Polystyrene (Styrofoam)

Mechanism An radical initiator is present. Written In.

Step-Growth Polymers Reaction between two different monomers A-A + B-B  [-A-A-B-B-A-A-B-B-] n

Example

Carboxylic Acids Contain a carboxyl group -COOH Polar molecules, Exhibit H bonding Smaller acids are water soluble Fairly high BP Much more acidic than alcohols –The two Oxygens make the H easily ionizable Low pH

Ester Synthesis Esters are prepared by reacting an alcohol and a carboxylic acid with an acid catalyst RCOOH + R’OH  RCOOR’ + H 2 O The OH from the acid and the H from the alcohol form the water Don’t need to worry about the mechanism

Propanol is reacted with butanoic acid. Determine the products of the reaction.

Reaction Consideration Product purification –The ester is a liquid and must be removed –The will be react and water in the flask too –Separate by distillation By BP

Salicylic acid reacts with acetic anhydride