Hierarchical structure and molecular orientation in injection molded PLCs

3 Hierarchical structure and molecular orientation in injection molded PLCs 

The morphology and properties of injection molded thermotropic longitudinal PLC products are similar to those of extrudates, i.e., macroscopic skin/core structure, microscopic hierarchically layered and 

Hedmark et al. [16] have studied injection molded bars with different thicknesses and they believed that the detectable layers and molecular orientation inside the layers depend on the thickness of the samples. 

Another aspect of morphology characterization is spectroscopic analyses of the molecular orientation. The simplest and most often used method is infrared (IR) spectroscopy. Although IR techniques cannot investigate the multilayered texture, they can readily provide vivid one- or two-dimensional profiles of molecular orientation vs. position. Bensaad et al. [17] used normal incidence specular reflection to characterize the orientation profile on the surface of an injection molded plaque (6 cm X 6 cm x 0.4 cm) made of a wholly aromatic thermotropic 

Hierarchical structures and molecular orientation in PLC products have not yet been fully understood and the experimental results are sometimes different or even contradictory. Complete understanding of the morphology and its formation need more effective characterization means and detailed knowledge of polymer flow in molds. However, 

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