Abstract
The mechanical anisotropy of uniaxially stretched PVA films was investigated experimentally and theoretically. The theoretical calculation of the mechanical anisotropy of the films was carried out of two structural models. The first calculation was performed by averaging the mechanical anisotropies of the oriented structural units on the basis of homogeneous stress hypothesis. On this calculation, a structural unit model was constructed by combining the orthorhombic crystallite with the isotropic amorphous phase in parallel or series to the reference axis. The other theoretical calculation of the mechanical anisotropy of the films was carried out of an averaged structural model which was obtained by averaging the orientations of crystallites and amorphous chains, respectively, and combining the averaged crystalline unit with the averaged amorphous phase in parallel and series to the stress direction. The anisotropy of amorphous phase in the averaged structural model was considered by assuming the affine deformation mechanism.
The result obtained from every theoretical calculation shows the experimental results of the uniaxially stretched PVA films in good agreement with each other.
