ABSTRACT
Macromoleculesareverylargemolecules.Oneclassofmacromoleculesiscommonlyknownaspolymers.Theterm“poly-mer”isderivedfromtheGreeklanguage, meaningmany-parts(i.e.,many-“mer”units).Themer-unitisthesmallestpossible combination of atoms forming a reactive chemical entity, that is, a molecule. Many suchidenticalmoleculeshavesuf–cientchemicalreactivitytocovalentlyconnect witheachother(typically>1000)toformamacromolecule.Moleculeswithonlya fewmer-unitsarecalledoligomers.Incontrasttopolymers,thephysicalproperties ofanoligomerchangewiththeadditionorremovalofoneormoremer-unitsfrom the molecule. The mer-unit is also called the repeat unit (Figure 2.1).
