Abstract
Some polyvinylchloride films were used for the specimens of amorphous polymer. The films were measured with respect to their stress relaxation and birefringence mutually reacting. After the specimens had been subjected to extreme tension and perfect relaxation, observation was made of their tension, their fluctuation in stress and birefringence under different temperatures were minutely examined.
The findings of the examination: The mechanical behviours of polyvinylchloride films show slight deviation from what they might be if rubberlike elasticity were perfect in the material, the deviation is only possible of being accounted for by presuming the presence of fine crystallites in the apparently simpler network structure in the films; and these crystallites are considered as subject to extinction and growth according to the rise and fall of temperature and strain.
