Side chain liquid crystalline polymers: Advances and applications

Liquid crystalline polymers (LCPs) are a class of polymers that show liquid crystal phase, they show both anisotropic properties which originate from mesogenic units and good mechanical properties which come from long-chain structures. Since the 1960s, LCPs have aroused considerable attention because of their wide applications as engineering plastics, high-strength and high-modulus fibers, electro-optic or nonlinear optic materials, stationary phases and their use as gas separation membranes, etc. On the basis of the manner in which the mesogenic units are incorporated into the polymers, LCPs are classified as main chain liquid crystalline polymers (MCLCPs) in which the mesogenic units are connected in the backbone, or side chain liquid crystalline polymers (SCLCPs) in which the mesogenic units are attached to the backbone as side pendants. Recently, researchers are focusing their attention on SCLCPs because they are key components for the development of liquid crystalline elastomers, which are poised for use as artificial muscles. SCLCPs also have many interesting applications in several fields, such as: optical data storage, chromatographic stationary phase, separation membranes and nonlinear optics. This chapter critically reviews recent advances and applications of SCLCPs.