Post-polymerization modification is a powerful strategy to endow polymers with functional groups that cannot be incorporated via direct polymerization. This manuscript explores the reversible addition-fragmentation chain transfer polymerization (RAFT) of pentafluorophenyl methacrylate (PFMA) to prepare active ester containing polymer brushes and investigates the feasibility and versatility of these reactive thin polymer films towards post-polymerization modification with a variety of amines. Post-polymerization modification of the PPFMA brushes was studied with FTIR and XPS and was found to proceed with near-quantitative conversion for most of the investigated amines. As they combine a high reactivity towards a broad range of amines with a good hydrolytic stability and swelling in a broad range of organic solvents, these PPFMA brushes represent an attractive platform for the preparation of libraries of functional polymer brushes via post-polymerization modification.