Self-repairing polymeric materials

The third and last section of our book deals with polymeric materials with bio-inspired functionality. The opening chapter by Waite gives a biological perspective of how mussels adhere to interfaces and emphasizes the importance of first understanding the biology before new, tmly bio-inspired materials can be achieved. The second chapter in this section, written by Lee, describes the synthetic achievements of mussel glue-inspired polymers, and depicts the polymer chemist s approach to mimic the mussel adhesion described by Waite in the previous chapter. Bruns and co-authors present a chapter on self-reporting polymeric materials with mechanochromic properties. Such materials mimic nature s ability to report, repair, and improve... 

Recent efforts to report and to repair mechanical damage with mechanochemical reactions form the subject of the current chapter. We start with a brief discussion of the use of the spiropyran unit as a mechanophore for reporting strain. Spiropyran mechanochemistry inspired the development of another stress probe, the highly sensitive mechanoluminescent dioxetane, whose application as scission reporter in several types of polymeric materials is discussed. The chapter continues with a description of recent efforts to develop productive mechanochemistry, where initial scission leads to the formation of new bonds. Bond formation is either induced by the scission of covalent bonds, e.g. by the opening of rings, or bonds are formed under the action of a latent catalyst when it is activated by mechanochemical dissociation of a Lewis acid-base pair. These examples of productive mechanochemistry offer exciting possibilities to develop new modes of self-healing in... 

The polymeric/ soft materials chapter represents the largest expansion for the 2nd edition. This chapter describes all polymeric classes including dendritic polymers, as well as important additives such as plasticizers and flame-retardants, and emerging applications such as molecular magnets and self-repairing polymers. This edition now features click chemistry polymerization, silicones, conductive polymers and biomaterials apphcations such as biodegradable polymers, biomedical devices, dmg delivery, and contact lenses. 

In Chapter 6, B. M. Rombo et al. delve into the formation of boronate-linked supramolecular architectures based on boronate ester formation—for example, small molecule diesters form supramolecular self-assemblies in the solid state based on a phenyl-boron-phenyl sandwich motif in which these small oligomers link together to generate macrocycles and other polymers. The polymeric macrocyclics and linear structures demonstrate self-repair capabilities and constitute a new class of wide band-gap semiconducting materials. Through the incorporation of polyvalent boronates, covalent organic frameworks are described, which create highly crystalline, porous network materials. 

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