June 1, 2019
Condensation Polymer
- Usually, two different types of monomers join to form condensation polymers.
- During the reaction, a small molecule (for example, water) is released.
- One example of condensation polymer is polyester.
Polyester
👇 Remember that an ester is formed when a carboxylic acid and alcohol react together 👇
A polyester is formed from two different monomers:
- a dicarboxylic acid, which contains two carboxylic acid groups (—COOH)
- a diol, which contains two alcohol groups (—OH)
☝️ The reaction to form a polyester from a dicarboxylic acid and a diol☝️
Notice that:
- Each monomer has functional groups on either end so that it can react and form ester links on both ends.
- Dicarboxylic acid loses OH group from each carboxyl group (—COOH).
- Diol loses H from each hydroxyl group (—OH).
- The remaining molecules join together to form polyester, and OH and H form water.
- The number of water molecules formed is twice the number of either monomer.
For example, a reaction between ethanedioic acid and ethanediol looks like this:
Biopolyester
Although most polyesters are non-biodegradable, specific types of polyesters called biopolyesters, are biodegradable. Then can be naturally decomposed by microbes after their intended use.