6.2.5: Condensation polymers Flashcards
What is polymerisation?
A chemical reaction that results in the production of a very long-chain molecule with repeating units- a polymer.
What are the two different types of polymerisation?
- Addition polymerisation
- Condensation polymerisation
When does addition polymerisation occur and give an example.
- When monomers have at least one C=C, which breaks and joins the other monomers together.
- There is only one type of product for this type of polymerisation.
- Common addition polymers include polyethene, made from ethene monomers.
When does condensation polymerisation occur?
- When two different monomers, with different functional groups, react to form a polymer and release another small molecule, often water, hence the name.
- Common condensation polymers include nylon and polyester.
What are polyesters?
A class of condensation polymers made by the chemical reaction of a dicarboxylic acid (-COOH) and a diol (-OH).
How are polyesters formed?
- When the carboxylic acid group on one monomer reacts with the alcohol group on the other monomer, an ester link (R-COO-R’) is formed between the two molecules.
- This happens many times ans produces a long-chain molecule, which is called a polyester.
How can a polyester be formed from just one monomer?
- Wen the monomer contains both an alcohol group and a carboxylic acid group.
- e.g. hydroxycarboxylic acid.
What are polyamides?
-A class of condensation polymers made by the chemical reaction of a dicarboxylic acid (-COOH) and a diamine (-NH2).
How are polyamides formed?
- When the carboxylic acid group on one monomer reacts with the amine group on the other monomer, an amide link (R-CONH-R’) is formed between the two molecules.
- This happens between many molecules and produces a long-chain molecule called a polyamide.
How can just one monomer be used to form a polyamide?
If the monomer contains both an amine group and a carboxylic acid group, one monomer can be used to form a polyamide.
-e.g. amino acids.