1992 Volume 20 Issue 3 Pages 146-152
The birefringence in injection molds of non-crystalline linear polymers arises from two different kinds of deformation; one incorporated with the change of intersegmental distance and one with the deformation of molecular conformation. Their contributions to birefringence were separately observed in injection molded polystyrene.
The birefringence originating from the molecular-conformational deformation was compared with computer simulation results, in which the rheology constitutive equation of Leonov was employed to calculate the shear and the normal stresses.
