The invention relates to a
polymer for treating a surface, which
polymer comprises: n
reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3; and m groups which comprise an atom-transfer
radical polymerization (ATRP) initiator, wherein m is an integer equal to or greater than 3, wherein the
reactive intermediate precursor groups are selected from
carbene precursor groups and
nitrene precursor groups, wherein the
carbene precursor groups are selected from
hydrazone groups of formula (A),
diazo groups of formula (B) and diazirine groups of formula (C), and the
nitrene precursor groups are
azide groups of formula (D), wherein R1 is H or -S(O)2R2, and R2 is an unsubstituted or substituted C1-6
alkyl group or an unsubstituted or substituted
aryl group. The invention also relates to a process for producing a treated substrate, which treated substrate has a surface suitable for surface -initiated atom-transfer
radical polymerization (SIATRP). The invention also relates to a treated substrate having a surface suitable for SIATRP, and to treated substrates obtainable by the aforementioned process of the invention. The invention also relates to a treated substrate which comprises: a substrate, a reacted
polymer disposed on a surface of the substrate, and a further polymer, grown by SIATRP, bonded to the reacted polymer.