Liquid crystalline polymer laminates
On the basis of a poly(ethylene terephthalate) copolyester containing 60 mol % p-hydroxybenzoic acid, thin liquid crystalline films (160 μm thick) are obtained by melting the polymer at 300°C and chilling at 0°C. The undrawn films obtained have a high degree of orientation as evidenced by X-ray measurements. Due to molecular orientation, these films are characterized by their excellent mechanical properties. In order to avoid losses in the mechanical strength due to increase in their thickness, laminates are prepared using thin liquid crystalline films. Lamination is carried out by annealing under pressure at 170°C for 6 h, resulting in samples with excellent mechanical properties regardless of their thickness. A method is proposed that makes it possible to combine the unique mechanical properties of thin films of liquid crystalline polymers with a lamination process in order to obtain thick and very strong materials.