Biodegradability of poly(alkenes), polyesters and polyamides：练习题

Which of the following polymers is most resistant to biodegradation in landfills?

Which statement best explains why poly(ethene) is not biodegradable, whereas proteins are easily broken down in the environment?

A synthetic polymer with the repeating unit shown in the diagram is subjected to prolonged reflux with aqueous sodium hydroxide. Which of the following correctly describes the chemical nature of this polymer and identifies the resulting hydrolysis products?

Which of the following polymers would be expected to degrade the most rapidly when buried in soil with a pH of 8.5?

A sample of a polyester is subjected to prolonged heating with aqueous sodium hydroxide. Which of the following best describes the resulting products?

Explain why poly(ethene) is not biodegradable, whereas poly(lactic acid) is capable of being broken down in the environment.

Compare the susceptibility of Terylene (a polyester) and Kevlar (a polyamide) to alkaline hydrolysis, and suggest which would degrade faster under basic conditions.

(a) Differentiate between addition and condensation polymerization. In your answer, refer to the requirements for monomer functional groups and the formation of by-products.

(b) Poly(propene) and nylon 6,6 are two common polymers.
(i) State the type of polymerization used to form each polymer.
(ii) Explain, in terms of their chemical structures, why poly(propene) is non-biodegradable while nylon 6,6 is potentially biodegradable.
(iii) Suggest the reagent and conditions required to chemically break down nylon 6,6 into its constituent monomers.