Abstract
Aromatic Polyamideimide (PAI) films were reinforced by aromatic polyamide fiber as unidirectionally oriented composite (Type 1), bidirectionally oriented laminate composite (Type 2), and bidirectionally oriented cloth composite (Type 3). The stress relaxation and thermal expansion of the composite films were investigated with respect to direction of fiber orientation. The behavior of the unidirectionally oriented composite film was more anisotropic than that of other composite films. In the cloth composite film, the elastic behavior was isotropic. The thermal expansion behavior was isotropic in the laminate composite film. Thus the anisotropy of elasticity of the composite films does not always correspond to that of thermal expansion.
