Accession Number : AD0869008

Title :   A Research Program on the Study of High Frequency Acoustical and Optical Sound Waves in Plastics and Rubbers and Their Interactions with Electromagnetic Laser Radiation.

Descriptive Note : Annual rept. no. 2, 2 Nov 68-31 Dec 69,

Corporate Author : OREGON UNIV EUGENE DEPT OF CHEMISTRY

Personal Author(s) : Peticolas, Warner L. ; Glaze, James ; Stein, Paul ; Edelson, Martin ; Hibler, Gary

Report Date : JAN 1970

Pagination or Media Count : 72

Abstract : Part I describes the measurement of the storage and loss modulus in compression for frequencies in the Gigahertz range. By measuring the frequency shift of the scattered light and the half width of the peak of the scattered light, we have been able to obtain the loss and storage modulus for the hypersonic waves generated thermally in the sample. Part II describes the measurement of the threshold for laser radiation induced fracture in a number of polymers and rubbers in the glassy and rubbery state. We find that there is an enormous increase in the laser power required for fracture above the glass transition. Part III outlines in detail the construction of several pieces of apparatus for the study of the Electron Spin Resonance, Optical and Stimulated Brillouin spectra of polymers during and after fracture. From an analysis of the results we have been able to put forth reasonable mechanisms for the fracture of various plastics. (Author)

Descriptors :   (*RUBBER, WAVE PROPAGATION), (*PLASTICS, WAVE PROPAGATION), LASERS, SOLID ROCKET PROPELLANTS, VISCOELASTICITY, POLYMERS, PHONONS, VIBRATION, ELECTRON PARAMAGNETIC RESONANCE, SOUND, SCATTERING, COMPRESSIVE PROPERTIES, FRACTURE(MECHANICS).

Subject Categories : Plastics
      Elastomers and Rubber

Distribution Statement : APPROVED FOR PUBLIC RELEASE