Brainlag PlusHow alkenes join into addition polymers and how to draw the repeat unit, condensation polymers such as polyesters, and the natural polymers DNA, proteins, starch and cellulose.
Addition polymers
Many small alkene molecules (monomers) join into one very long molecule (a polymer).
The C=C double bond in each monomer opens and links to the next. Nothing else is made.
To draw the repeat unit: copy the two carbons and their side groups, make the C to C bond single, add a bond out each side through square brackets, and write n.
The polymer is named poly(monomer): ethene makes poly(ethene), propene makes poly(propene), chloroethene makes poly(chloroethene) (PVC).
The side groups never move or change. Only the double bond becomes single.
The rest of this lesson and its 11 practice questions are in Plus.
Screen 1 of 4, free to read.
- 11 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards