polymerisation

Question 1

what are condensation polymers

Answer 1

they form when a water molecule is removed from the species of a reaction

Question 2

what are the three main types of condensation polymers

Answer 2

• polyamide
• polyesters
• polypeptides

Question 3

how are polyamides formed

Answer 3

in a reaction between diarboxylic acid and a diamine. a moleucle of water is removed leaving an amide linkage (-CONH-)

Question 4

features of polyamides

Answer 4

normally formed from long chain molecules, which provides them with strength

Question 5

examples of polyamides

Answer 5

• nylon - 6,6 - made from hexamethlyenediamine and hexandioic acid
• Kelvar - made from 1,4-benzendicarboylic acid and 1,4-benzenediamine

Question 6

how are polyesters formed

Answer 6

are formed in a reaction between dicarboxylic acids and a diol, producing an ester linkage (-COO-)

Question 7

example of a polyester

Answer 7

Terylene (PET) - made from ethanediol and 1,4-benzenedicarboxylic acid

Question 8

polypeptides

Answer 8

formed from multiple amino acids. A single monomer can produce a polymer due to the presence of both a -NH and -OH group. peptide linkage (-CONH-)

Question 9

hydrolysis

Answer 9

Condensation polymers can be broken down into the constituent molecules by the addition of H2O. as water is attracted to polar regions of the polymer, the links can be broken down

Question 10

Features of condensation polymers and their uses

Answer 10

H bonding and dipoles form between separate polymer chains, holding them together in a strong structure, useful for bulletproof vests/ heat protective materials

Question 11

Why are polyalkenes (addition polymers) difficult to dispose of

Answer 11

are inert with non-polar bonds, so species in nature can’t break them down. They are not biodegradable and broken down by burning which produces SO2/CO, leading to acid rain

Question 12

How are polyesters broken down

Answer 12

• hydrolysis so are biodegradable
• with HCL - form og dicarboxylic acid + diol
• with NaOH - form diol + dicarboylate salt

Question 13

How are polyamides broken down

Answer 13

hydrolysis so are biodegradable

• with HCL - form og dicarboxylic acid + diamine
• with NaOH - form diamine + dicarboylate salt

Question 14

how can polyalkenes be broken down

Answer 14

They are chemically inert and non-biodegradable, so they have no polar bonds. broken down by burning releasing SO2 or CO

Question 15

disposal of polymers
landfill

Answer 15

• common
• most are reaching capacity
• takes years to break down

Question 16

disposal of polymers
incineration

Answer 16

• rubbish burn -> energy produced to generate electricity
• toxins and pollutants can be removed
• emitts greenhouse gases
• volume of rubbish reduced

Question 17

dispsal of polymers
recycling

Answer 17

• saves raw materials
• polymers need sorting - expensive in terms of energy + manpower
• polymers can only be recycled into the same type, so careful separation is needed
• thermoplastic polymers can be melted and reshaped