Polymers

Question 1

Addition

Answer 1

An addition polymer forms when unsaturated monomers react to form a polymer
Monomers contain C=C bonds

Question 2

polyalkenes biodegradable

Answer 2

Poly(alkenes) are chemically inert due to the strong C-C and C-H bonds and non-polar nature of the bonds and therefore are non-biodegradable.

Question 3

Condensation

Answer 3

polyesters and polyamides which involve the formation of an ester linkage or an amide linkage.

In condensation polymerisation there are two different monomers that add together and a small molecule is usually given off as a side-product e.g. H2O or HCl.

The monomers usually have the same functional group on both ends of the molecule e.g. di-amine, di carboxylic acid, diol, diacyl chloride.

Question 4

Carboxylic Acid + Alcohol

Answer 4

Ester + water

Question 5

Carboxylic Acid + Amine

Answer 5

amide + water

Question 6

Acyl chloride + Alcohol

Answer 6

Ester + HCl

Question 7

Acyl chloride + Amine

Answer 7

amide + HCl

Question 8

dicarboxylic acid + diol

Answer 8

poly(ester) + water

Question 9

dicarboxylic acid + diamine

Answer 9

poly(amide) + water

Question 10

diacyl dichloride + diol

Answer 10

poly(ester) + HCl

Question 11

diacyl dichloride + diamine

Answer 11

poly(amide) + HCl

Question 12

Terylene

Answer 12

n O=C-⏣-C=O
HO- -OH

and ethan-1,2-diol
HO-CH2-CH2-OH

Question 13

Nylon 6,6

Answer 13

hexanedioic acid + hexane-1,6-diamine

Question 14

Hydrolysis

Answer 14

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

The reactivity can be explained by the presence of polar bonds which can attract attacking species such as nucleophiles and acids

Question 15

Intermolecular bonding between condensation polymers chains

Answer 15

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.
Polyamides will therefore have higher melting points than polyesters.

Question 16

Landfill

Answer 16

The most common method of disposal of waste in UK
Many are now reaching capacity.
European regulations will mean councils are charged much more for using landfill.
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

Question 17

Incineration

Answer 17

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.

Question 18

Recycling

Answer 18

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