X-Ray Diffraction Studies of the Relaxation of Ethylene-Methacrylic Acid Copolymers and Their SaltsMacromolecules (1971)
The degrees of crystallinity and crystal orientation of quenched and annealed ethylene-methacrylic acid co polymers and their salts are studied by X-ray diffraction. The degrees of crystallinity of the annealed acid and salt are comparable with those of branched polyethylene but the crystallinity of the quenched acid is reduced by about half. Orientation functions for crystal axes have been determined as a function of the temperature of elongation and are used to calculate the crystalline component of birefringence. It is found that crystalline orientation makes an appreciable contribution to the birefringence. The change in orientation function with elongation varies with temperature in a very different manner for the acid and the salt, suggesting different orientation mechanisms for the two. At a temperature corresponding to the a mechanical dispersion, a marked increase is seen in the amorphous orientability of the salt, whereas no such increase is found for the acid. This suggests that a process occurs within the amorphous phase of the salt at this temperature, permitting greater orientation to occur. This is consistent with the assignment of this loss maximum to a softening temperature of a proposed ionic domain.
- Acid Copolymers,
Citation InformationWilliam MacKnight, T. Kajiyama, T. Oda and R. S. Stein. "X-Ray Diffraction Studies of the Relaxation of Ethylene-Methacrylic Acid Copolymers and Their Salts" Macromolecules Vol. 4 (1971) p. 198 - 203
Available at: http://works.bepress.com/william_macknight/32/