Grafting of Electroactive Polymers

Abstract

The grafting of copolymers has received significant attention due to the successful integration of their properties, both the backbone and graft chain polymers. The matter becomes even more interesting when the reactive/stimuli responsive polymeric chains are grafted onto backbone polymer, which offers unique physical properties such as crystallization or optoelectronic properties, etc. Such graft copolymer materials are very promising for the opening of new horizons of applications both in industry and academia. The grafting of reactive/responsive polymer chains onto commercially available polymers for greater manipulation of their properties is an attractive field of research. Grafting onto commercially available membrane-forming polymers such as poly(vinyledene fluoride) (PVDF) has aroused significant interest due to the possibilities of stimuli dependent membrane pore size modulation, supramolecular interactions have boosted its applications for affinity-based chromatography. Similarly, graft copolymers based on conjugated polymer backbones are also very much interesting, since interactions of the grafted chains with the external chemical or physical stimuli (such as pH, photoirradiation, salts, surfactants, temperature changes, etc.) significantly affect the conformation of the backbone chain, both in the solution state, gel state and solid state. This leads to changes in the optical response of the backbone polymers which are very useful in sensor applications, since the photo-responsivity of polymer systems is much stronger than small molecules due to signal amplification even under tiny perturbation. In most cases, grafting is done following an uncontrolled free radical-driven polymerization protocol, which associates threats to backbone degradation, the formation of high molecular weight graft chains, which affect the native properties of the backbone irreversibly. However, in order to keep the native properties of the backbone polymer intact, the grafting of polymeric chains must be performed in a controlled manner. In the present chapter, different strategies for the controlled grafting of neutral or ionic polymeric chains onto electroactive polymers and impact of the reactivity of the grafted chains onto the polymer property will be discussed.