ORIENTATION DEVELOPMENT IN INJECTION MOLDED PLAQUE OF LIQUID-CRYSTAL COPOLYESTERAMIDE USING NORMAL INCIDENCE SPECULAR REFLECTION

The orientation development that takes place during injection moulding of liquid crystalline polymer (LCP) is analysed by FTi.r. specular re flection. The LCP used is the commercial Hoechst-Celanese product Vect ra B900 based on terephthalic acid, p-aminophenol and 6-hydroxy 2-naph thoic acid. Dichroic ratios were measured from the 1016 cm-1 absorptio n band which is associated with a vibration of the 1,4-disubstituted b enzene rings. The results, which are in good agreement with previous p hotoacoustic measurements, show that orientation is maximum along the principal axis of the mould with two significant minima of orientation located approximately at 2 and 3.2 cm from the injection gate. Furthe rmore, as the sample position shifts along the transverse direction to wards the mould edge, there is a marked fall-off in orientation and th e orientation minima occur at positions closer to the gate.