Polymers (Cambridge (CIE) IGCSE Combined Science: Chemistry): Flashcards

A polymer is a large molecule built up from many smaller repeating units called monomers joined together by covalent bonds.

A monomer is a small molecule that can join with many other monomers to form a long-chain polymer. For example, ethene is the monomer used to make poly(ethene).

Poly(ethene) is formed by the addition polymerisation of ethene monomers.

False.

In addition polymerisation, only one product is formed. The monomers join together as the C=C double bond breaks, and no other molecules are produced as byproducts.

The monomer must be an alkene because it contains a C=C double bond. During addition polymerisation, this double bond breaks and the monomers link together. Saturated compounds without a double bond cannot undergo this reaction.

1. Poly(ethene) (polythene)

2. PVC (polyvinyl chloride)

3. Nylon (though strictly nylon is a condensation polymer, the syllabus lists it; poly(ethene) and PVC are the key addition polymers)

During addition polymerisation of ethene, the C=C double bond breaks and monomers join together to form a long-chain polymer.

True.

Each monomer in a polymer chain is joined to the next by covalent bonds formed when the C=C double bond breaks and new C-C single bonds are created.

The C=C double bond breaks during addition polymerisation. One bond of the double bond breaks in each monomer, allowing the carbon atoms to form new single bonds with the adjacent monomers in the growing polymer chain.