Summary and Exam Tips for Polymers
Polymers is a subtopic of Organic Chemistry, which falls under the subject Chemistry in the Cambridge IGCSE curriculum. Polymers are long chain molecules formed from small units called monomers. They are categorized into synthetic and natural polymers. Synthetic polymers are further divided based on their formation process: addition polymerization and condensation polymerization.
- Addition polymerization involves the joining of monomers with a C=C double bond, such as in the formation of poly(ethene).
- Condensation polymerization involves two different monomers with functional groups, releasing a small molecule like water. Examples include nylon (a polyamide) and terylene (a polyester).
Natural polymers, like proteins, are formed from amino acids linked by amide bonds. Proteins are natural polyamides, similar to synthetic polyamides like nylon. The environmental impact of polymers, particularly non-biodegradable plastics, poses significant challenges. Recycling processes, such as the depolymerization of PET, help mitigate these issues by converting polymers back into monomers for reuse.
Exam Tips
- Focus on understanding the functional groups involved in polymerization and the types of linkages formed.
- Be able to differentiate between addition and condensation polymerization processes.
- Practice drawing the structures of polymers like nylon and PET, emphasizing the linking ester or amide groups.
- Remember that PET can be depolymerized and re-polymerized, highlighting its recyclability.
- Consider the environmental implications of synthetic polymers, especially their disposal and recycling challenges.
