Abstract:
The polarized and depolarized components of light scattering by pure poly-(methyl methacrylate) (PMMA) were measured as a function of temperature above and below Tg. The PMMA sample used was prepared by a very careful procedure in which the evaporable monomer, initiator, and chain transfer agent were distilled in a closed vacuum system and in-situ polymerization was carried out above Tg. The measured Vviso intensities were favorably compared with the values calculated from thermal density fluctuation in the temperature range from 20 to 140°C. The measured intrinsic Hv intensity was fairly close to the value calculated assuming a randomly oriented anisotropic liquid for PMMA. Our experiment showed no evidence for an ordered structure in pure PMMA glass, as is found in pure polystyrene glass.
