Accession Number:

ADA303579

Title:

Friction Transition In Polyimide Films as Related to Molecular Relaxations and Structure.

Descriptive Note:

Technical note,

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s):

Report Date:

1975-04-01

Pagination or Media Count:

31.0

Abstract:

The friction characteristics of polyimide films bonded to metallic substrates were studied from 25 C to 500 C. These results were correlated to molecular structure and the results of torsional braid analysis TBA. A large friction transition 0. 23 to 0.03 was found to occur at 45 C OR - 5 C. It was postulated that this transition was initiated by some molecular relaxation, which gave the molecules a degree of freedom by which an external mechanical stress could rearrange the molecules into a structure, such as an extended chain, which is conducive to easy shear. Above 300 C the friction characteristics were found to be dependent on the thermal prehistory of the film. MM

Subject Categories:

  • Lubricants and Hydraulic Fluids
  • Plastics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE