Accession Number : ADA308234

Title :   Time and Temperature Dependent Modulus of Pyrrone and Polyimide Moldings.

Descriptive Note : Contract rept.,

Corporate Author : AVCO CORP LOWELL MA SYSTEMS DIV

Personal Author(s) : Lander, L. L.

PDF Url : ADA308234

Report Date : JAN 1972

Pagination or Media Count : 80

Abstract : A method is presented by which the modulus obtained from a stress relaxation test can be used to estimate the modulus which would be obtained from a sonic vibration test. The method was applied to stress relaxation, sonic vibration, and high speed stress-strain data which was obtained on a flexible epoxy. The modulus as measured by the three test methods was identical for identical test times, and a change of test temperature was equivalent to a shift in the logarithmic time scale. An estimate was then made of the dynamic modulus of moldings of two Pyrrones and two polyimides, using stress relaxation data and the method of analysis which was developed for the epoxy. Over the common temperature range (350 deg to 500 deg K) in which data from both types of tests were available. the estimated dynamic modulus value differed by only a few percent from the measured value. As a result, it is concluded that, over the 500 deg to 700 deg K temperature range. The estimated dynamic modulus values are accurate.

Descriptors :   *TIME DEPENDENCE, *MOLDINGS, *POLYIMIDE RESINS, TEST AND EVALUATION, STRESS STRAIN RELATIONS, DATA PROCESSING, TEMPERATURE, HIGH RATE, STRESS TESTING, TEST METHODS, STRESS RELAXATION.

Subject Categories : Polymer Chemistry
      Organic Chemistry
      Miscellaneous Materials
      Plastics
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE