The sensitivity of random polymer brush-lamellar polystyrene-b-polymethylmethacrylate block copolymer systems to process conditions

► PS-r-PMMA polymer brushes are effective over a wide range of molecular weights. ► PS-b-PMMA nanopatterns evolution depend on the anneal period. ► Re-orientation of blocks and domain size variations are observed. ► Degradation of the PMMA component causes these changes.