Study of macromolecular Brownian motion by laser light scattering, part 1. Light scattering investigation of amorphous polymethylmethacrylate, part 2
Abstract
The light scattered from dilute solutions of three different molecular weight polystyrene molecules in cyclohexane, diethylmalonate, and 1-chloroundecane was examined at their respective theta temperatures. The autocorrelation functions collected were fitted to a single exponential function decay time which yielded the diffusion coefficient. The correlation technique was also used to study the light scattered from amorphous polymethylmethacrylate for a range of temperatures from 6 C to 165 C. Data were analyzed in terms of two exponential decays and the angular dependence of each of the corresponding relaxation frequencies was examined. The results for the high frequency relaxation mode are angular independent and fall reasonably well on two straight lines of different activation energy indicating the presence of two coupled relaxation mechanisms.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1977
- Bibcode:
- 1977PhDT........23S
- Keywords:
-
- Amorphous Materials;
- Brownian Movements;
- Laser Beams;
- Lasers;
- Light Scattering;
- Molecular Relaxation;
- Polymethyl Methacrylate;
- Autocorrelation;
- Diffusion Coefficient;
- Polystyrene;
- Relaxation (Mechanics);
- Relaxation Time;
- Physics (General)