Abstract
An anneling effect in uniaxially stretched polyvinyl alcohol dyed with Congo Red was studied by x-ray diffraction, visible dichroic ratio and birefringence as a function of molecular orientation.
The following results were obtained:
1) The shrinkage for the specimens annealed at a released state was explained by the recovery of the orientation in the noncrystalline chain with the release of the tension and by the fold back from the noncrystalline chains to the crystal one.
2) The phenomena of spontaneous elongation occured for the low elongated specimens annealed at a stretched state appeared.
3) The increase in orientation of the noncrystalline chains as well as the crystalline chain axis for the high elongated one was less than that for the low elongated one for the annealed specimens at a stretched state.
4) It was found that for the annealing under the molecular orientation, the noncrystalline orientation factor evaluated from the visible dichroism was in agreement with that calculated by assuming the additivity of birefringence of each for the total to be valid.
