The orientation development that takes place during injection moulding of liquid crystalline polymer (LCP) is analysed by FTi.r. specular reflection. The LCP used is the commercial Hoechst-Celanese product Vectra B900 based on terephthalic acid, p-aminophenol and 6-hydroxy 2-naphthoic acid. Dichroic ratios were measured from the 1016 cm 1 absorption band which is associated with a vibration of the 1,4-disubstituted benzene rings. The results, which are in good agreement with previous photoacoustic 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. Furthermore, as the sample position shifts along the transverse direction towards the mould edge, there is a marked fall-off in orientation and the orientation minima occur at positions closer to the gate.
Посилання на статтю:
Orientation development in injection moulded plaque of liquid crystal copolyesteramide using normal incidence specular reflection / S. Bensaad, B. Jasse* and C. Noel // Polymer. – 1993. – Vol 34. – P. 1602-1605.