Polymers

Addition and condensation

When unsaturated monomers react to form a polymer

Strong C-C and C-H bonds

It is best to first draw out the monomer with groups of atoms arranged around the double bond basically lay them out as e-z isomers

Ester link- when making polyesters Amide links when making polyamids

H2O or HCl

Carboxylic acid + alcohol –> ester + water Acyl chloride + alcohol –> ester + HCl Carboxylic acid + amine –> amide + water Acyl chloride +amine –>amide + HCl If it is the di versionof any of them they form polys so like dicarbolxylic acids + diol forms poly esters plus water

It is polyamide or polyester Whereas type of polymerisation is condensation

polyesters and polyamides can be broken down by hydrolysis and are, therefore, biodegradable The reactivity can be explained by the presence of polar bonds

Polyesters and polyamides can be hydrolysed by acid and alkali The hydrolysis will result in the original monomers forming-although the carboxylic acid or amine group will be in salt form depending on whether the conditions are alkaline or acidic

Polyesters have permanent dipole forces between the Cδ+=Oδ-groups in the different chains in addition to the Van der Waals forces between the chains. Polyamides (and proteins) have hydrogen bonding between the oxygen in Cδ+=Oδ-groups and the H in the Nδ-—Hδ+groups in the different chains in addition to the Van der Waals forces between the chains. Polyamides will therefore have higher melting points than polyesters.

Landfill The most common method of disposal of waste in UK Many are now reaching capacity. Most polymers (polyalkenes) are non-biodegradable and take many years to break down. Could use more biodegradable plastics, e.g. Polyamides and cellulose and starch based polymers to improve rates of decomposition

Rubbish is burnt and energy produced is used to generate electricity. Some toxins can be released on incineration. Modern incinerators can burn more efficiently and most toxins and pollutants can be removed. Greenhouse gases will still be emitted though. Volume of rubbish is greatly reduced.

Saves raw materials-nearly all polymers are formed from compounds sourced/produced from crude oil. Saves precious resources. Polymers need collecting/ sorting-expensive process in terms of energy and manpower. Polymers can only be recycled into the same type –so careful separation needs to be done. Thermoplastic polymers can be melted down and reshaped

Benzene 1,4 dicarboxylic acid and 1,4 diaminobenzene react to form kevlar Takes away OH from COOH and H from NH2 When drawing the repeat unit you need both Benzene 1,4 dicarboxylic acid and 1,4 diaminobenzene in it

Hexanedioic acidCOOH(CH2)4COOH +1,6 diaminohexane

Used in plastic bottles