Abstract
Highly doubly-oriented specimens of polyvinyl alcohol (PVA) were prepared by rolling a sheet of cast PVA film and by subsequent annealing. Detailed X-ray examinations of crystallite orientation were made on packs of the specimens.
The results show that (101) planes, which have been considered to be oriented parallel to the film surface, are tilted by 2-3 degrees from the film surface. In thccases, ofcast: PVA film and stretched film, tilting of the (101) planes was same as in the case of rolled film. According to Bunn's model, it follows that the zigzag planes of carbon-carbon chains in crystallites coincide with the film surface. It is concluded that not the lattice planes of the crystals but the planes of molecular chains have the tendency to be parallel to the surface of the film.