A BCP having first block of first monomer and second block of second monomer, adapted to undergo a transition from disordered state to ordered state at a temperature less than TOD, further including a bridging moiety having a functional group to provide hydrogen bonding between bridging moieties of adjacent first and second BCP molecules when in the ordered state and at a temperature in excess of a glass transition temperature Tg for the BCP. Composition including BCP comprising first block of first monomer and second block of second monomer, and a crosslinking compound having first and second terminal groups joined by a central moiety and arranged to crosslink second blocks of adjacent first and second BCP molecules by providing non-covalent bonding between the terminal groups and a functional group of the second monomer of the second blocks when the BCP is in the ordered state.