Molecular level study of the crystallization of a thermoplastic polyimide by infrared spectroscopy

Abstract

The crystallization process of the thermoplastic polyimide derived from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) and 2,2‐dimethyl‐1,3,‐(4‐aminophenoxy) propane (DMDA) is studied at the molecular level by utilizing infrared spectroscopy's sensitivity to local molecular environment. Assignments of the unique spectral features appearing upon crystallization are made with additional verification from crystalline model imide compounds. A direct comparison of an annealed polyimide film studied by both infrared spectroscopy and x‐ray diffraction shows fairly close agreement in the amount of crystallinity obtained. The unique crystalline infrared spectral features provide insight into the molecular mechanism involved with the crystallization process. Spectral shifts occurring upon crystallization reflect intramolecular rotations toward increased coplanarity as well as intermolecular chain packing of certain molecular groups at specific sites of the chain backbone. The site specific information is then used to study the relative kinetic behavior of the intramolecular and intermolecular effects occurring during crystallization. © 1994 John Wiley & Sons, Inc.

Plasticization mechanisms and effects of thermal annealing of Matrimid hollow fiber membranes for CO2 removal

“…This observation indicated that the concentration of benzophenone carbonyl group decreased compared to the concentration of imide carbonyl group during thermal annealing. The reduced concentration of the benzophenone carbonyl might be attributed to the possible crystallization of Matrimid during thermal annealing which could improve membrane separation properties [15,60].…”

Chemical degradation of polyimide and polysulfone films under the irradiation with heavy ions of several hundred meV

“…4) characterizing the transverse stretching mode of CNC in the imide group. [21][22][23] The decay of this band is stronger for the Mo irradiation indicating enhanced destruction of the imide ring if oxygen is available during the exposure to the ion beam (Fig. 4).…”

Tribophysical Interpretation of Polymer Sliding Mechanisms

“…Thermal degradation of aromatic structures into monomers weakens strength and results in high wear rates. The C=O stretching mode for thermoplastics varies stronger than for thermosetting polyimide 33,34 . The Raman shifts do not develop continuously, but they decrease mainly above 180°C in parallel to a transition in friction and wear regime.…”