4 - Mechanical properties of conjugated polymers

Abstract

A balance of mechanical integrity, stiffness, flexibility, and materials performance is one of the most important tasks to be undertaken while designing the conjugated polymer (CP)-based optoelectronic devices. The deformation behavior of such materials in different length scales (molecular, mesoscopic, and macroscopic levels) can be optimized by controlling the synthetic parameters, processing conditions and blending with other polymers and inorganic substances. Thus, detailed understanding of structure–mechanical–property correlations of polymers that can be assessed by various ways including the use of in situ techniques is crucial part of novel materials designs. This chapter addresses first the morphology–property relationship particularly taking into account the essence of microstructural construction of polymeric materials. The hierarchical morphological diversity is highlighted with typical examples chosen from selected classes of CPs and their derivatives. Different methods of mechanical properties characterization are briefly introduced. The various factors influencing the mechanical deformation behavior of CPs with special emphasis on molecular, temperature, regioregularity, and various architectural parameters have been discussed. Finally, an outlook emphasizing the need to explore in situ imaging techniques for the simultaneous elucidation of structure and deformation mechanisms of CPs have been highlighted.