Accession Number : ADA304555

Title :   A Water-Sensitive Thermomechanical Transition in a Polyimide.

Descriptive Note : Technical rept. Feb 77-Feb 78,

Corporate Author : PRINCETON UNIV NJ DEPT OF CHEMICAL ENGINEERING

Personal Author(s) : Ozari, Y. ; Chow, R. H. ; Gillham, J. K.

PDF Url : ADA304555

Report Date : FEB 1978

Pagination or Media Count : 35

Abstract : The effect of water vapor on a polyimide has been investigated in the temperature region -190 deg to 325 deg C using an automated torsion pendulum. A damping peak 'TH2O' develops at -122 C (1 Hz) in the thermomechanical spectra of the polymer which is due to water-polymer interactions. The peak intensifies as the humidity of the conditioning atmosphere, at both 30 C and at 325 C, increases and attains a limiting value at about 2000 ppm sub v H20. The process is reversible. It is concluded that the number of sites in the polymer for interaction with water is low and limited and, assuming direct proportionality between the intensity of the loss peak and the amount of water adsorbed, that the adsorption of water vapor follows the Langmuir isotherm. (MM)

Descriptors :   *THERMOMECHANICS, *POLYMERS, *POLYIMIDE PLASTICS, *WATER CHEMISTRY, PEAK VALUES, MOLECULES, ADSORPTION, SENSITIVITY, MOLECULAR STRUCTURE, LANGMUIR PROBES, ISOTHERMS, TORSION, WATER VAPOR, PENDULUMS, POLYIMIDE RESINS.

Subject Categories : Polymer Chemistry
      Plastics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE