PMMA is a rigid polymer. The repeat unit of PMMA is shown.
Which monomer is used to make PMMA?
Correct Answer: \( \boxed{\mathrm{D}} \)
PMMA is formed by addition polymerisation of methyl methacrylate.
The monomer must contain both:
Only Structure D is methyl methacrylate, \(\mathrm{CH_2=C(CH_3)COOCH_3}\).
Therefore, the correct answer is (D).
A section of an addition polymer is shown.
Which monomer is used to make this polymer?
Correct Answer: \( \boxed{\mathrm{A}} \)
The polymer backbone is formed by addition polymerisation of a carbon-carbon double bond.
Each repeat unit contains an acetate ester group, \(\mathrm{-OCOCH_3}\), attached to alternate carbon atoms of the polymer chain.
This repeat unit is produced from vinyl ethanoate (vinyl acetate), \(\mathrm{CH_2=CHOCOCH_3}\).
Among the structures shown, this corresponds to Structure A.
Therefore, the correct answer is (A).
A small section of a polymer produced from two monomers is shown.
\(\mathrm{-CH_2-C(CH_3)_2-CH(CH_3)-CH_2-}\)
What are the two monomers?
Correct Answer: \( \boxed{\mathrm{D}} \)
In an addition polymer, each monomer contributes a repeating unit obtained by opening its carbon-carbon double bond.
The fragment \(\mathrm{-CH_2-C(CH_3)_2-}\) is produced from methylpropene, \(\mathrm{CH_2=C(CH_3)_2}\).
The fragment \(\mathrm{-CH(CH_3)-CH_2-}\) is produced from propene, \(\mathrm{CH_2=CHCH_3}\).
Therefore, the two monomers are methylpropene and propene, so the correct answer is (D).
