Liquid Crystalline Composite

Abstract

Abstract A review of novel technologies for manufacturing composites involving liquid crystalline polymers (LCPs) is presented. In particular, this review provides a classification scheme of various types of LCPs, with a special emphasis paid to the history, key approaches, milestones in developments of thermotropic LCPs, and their commercialization. Methods of characterization of LCPs by optical and electron microscopy, X‐ray diffraction, NMR, light scattering, and thermal, rheological, and mechanical techniques are discussed. The development of the concept of self‐reinforced or in situ composites based on blending LCPs with flexible‐chain polymers and LCPs with other LCPs is presented. In these composites, the dispersed fibrous reinforcing LCP species in polymer matrices are not actually present before the processing of the resin, but come into existence during the processing step. Various aspects of manufacturing of these composites are discussed including methods of mixing and compounding, transition temperatures, different factors governing LCP fibrillations, effects of LCP on crystallization of thermoplastic matrices, rheology of composites, and the use of LCP as a processing aid for thermoplastics. Special attention is paid to manufacturing and mechanical properties of the composites based on LCP/thermoplastic, LCP/LCP and ternary blends, and LCP/thermoplastic and LCP/LCP laminates. The effect of compatibilization and anisotropy of composites are also considered along with proposed approaches to reduce their anisotropy. Finally, various existing and future possibilities for industrial applications of self‐reinforced composites are discussed.