Quantitative analysis of rotational dynamics in doped polymers above and below the glass transition temperature: a novel application of second-order nonlinear optics. Dhinojwala, Ali; Wong, George K.; Torkelson, John M. Dep. Chem. Eng., Northwestern Univ., Evanston, IL, USA. Macromolecules (1992), 25(26), 7395-7. CODEN: MAMOBX ISSN: 0024-9297. Journal written in English. CAN 117:252408 AN 1992:652408 CAPLUS

The av. rotational time consts. and rotational diffusion coeffs. of (dimethylamino)nitrostilbene doped in poly(iso-Bu methacrylate) were measured by 2nd harmonic generation. This study represented a significant advance in that an alternative exptl. protocol in which the laser pulse was triggered from 200 ms to 0.5 s after switching the d.c. poling field on (poling onset measurement) or off (temporal decay measurement) was used in conjunction with normal time-domain measurements, allowing dynamics to be monitored over time scales £10 orders of magnitude from 10-4 s to as long as required (potentially 106 s).