ABSTRACT
The word polymer literally means “many parts.” A polymer is a macromo lecule that contains many groups of atoms, called monomeric units, that are covalently bonded. The simplest hydrocarbon chain polymer is polyethy lene, with the general formula:
$, iC H 2-CH23r $2
obtained from the monomer ethylene, H2C = CH2. The number of ethylene monomeric units, n , can reach values between
103 and 106. For high molecular weight chains, terminal groups <\>x and cj)2 are present in low concentrations and will therefore have no effect on the
mechanical properties of the polymer. Terminal groups influence mainly the chemical stability of the polymer. Heating or irradiation can provoke the degradation of polymers with unstable terminal groups.
