text: In polymer chemistry and materials science, the term "polymer" refers to large molecules whose structure is composed of multiple repeating units. Supramolecular polymers are a new category of polymers that can potentially be used for material applications beyond the limits of conventional polymers.  By definition, supramolecular polymers are polymeric arrays of monomeric units that are connected by reversible and highly directional secondary interactions–that is, non-covalent bonds.  These non-covalent interactions include van der Waals interactions, hydrogen bonding, Coulomb or ionic interactions, π-π stacking, metal coordination, halogen bonding, chalcogen bonding, and host–guest interaction.  The direction and strength of the interactions are precisely tuned so that the array of molecules behaves as a polymer (that is, it behaves in a way that can be described by the theories of polymer physics) in dilute and concentrated solution, as well as in the bulk.
  In conventional polymers, monomeric units are linked by strong covalent bonds and have excellent properties as materials; however, high temperatures and pressures are typically required for processing due to polymer entanglement in the highly viscous melt.  Supramolecular polymers combine good material properties with low-viscosity melts that are easy to handle.  Additionally, some supramolecular polymers have unique characteristics, such as the ability to self-heal fractures.  Although covalent polymers can be recycled, their strong covalent bonds never disintegrate, and go on to negatively affect the environment as plastic wastes.  Thus, supramolecular polymers are increasingly getting attention because of their potential for the design of responsive, adaptive, self-healing, and environmentally friendly materials.