Synthetic polymers

How is an addition polymer formed?

Many small molecules called monomers join together to create very large molecules called polymers

What are the rules to drawing the repeat unit of an addition polymer?

• No brackets

• Double bond into single bonds

• Single bonds should extend to the sides

• Everything else stays the same

Draw the repeating unit of poly(ethene)

Draw the repeating unit of poly(propene)

Draw the repeating unit of poly(chloroethene)

Draw the repeating unit of poly(tetrafluroethene)

What are the problems in disposal of addition polymers

• Their inertness (inability to react), means that microorganisms and bacteria are unable to break them down, causing accumulation

• When they are burned, carbon dioxide is released which contributes to global warming

What is condensation polymerisation?

The process which monomers combine to form a polymer, while releasing small by-products like water

What does the term diol mean?

It means the presence of 2 alcohols

What is the general formula for making a polyester?

diol + dicarboxylic acid —> polyester + water

How does condensation polymerisation work for polyesters to form?

• A diol (alcohol with 2 OH groups) bonds with a dicarboxylic aicd (carboxylic acid with 2 COOH groups)

• As part of the process, the dicarboxylic acid loses the OH group off of each COOH group

• the diol loses the H off of each OH group

• Remaining molecules join together to make a polyester

• H and O join to form water

What are the rules to drawing the repeating unit of a polyester?

• Identify the OH from carboxylic acids and H from alcohols to form H₂O

• Draw just one of each diol and dicarboxylic acid and a single bond at each end

• No brackets

What is the structural formula for a reaction between ethanedioic and ethanediol

Which type of polyesters are biodegradable?

• biopolyesters, meaning they are easier to dispose of

• can be made from lactic acid obtained from cornstarch