ISSN:
0887-6266
Keywords:
nonlinear optical polymer
;
pressure
;
chromophore reorientation
;
poly(alkyl methacrylates)
;
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Activation volumes for chromophore reorientation were measured for a series of guest-host polymeric materials, indicating a significant coupling between chromophore motion and the glassy α and β relaxation dynamics of the polymer host. The specific systems studied were formed by individually dissolving N,N-dimethyl-p-nitroaniline (DpNA), 4-(dimethylamino)-4′-nitrotolane (DMANT), 4-(diethylamino)-4′-nitrotolane (DEANT), and 1-((4-(dimethylamino)phenyl)ethynyl)-4-((4-nitrophenyl)ethynyl)benzene (DMAPEANT) in poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), and poly(isobutyl methacrylate) (PiBMA). In each of these systems, the isothermal, sub-Tg decay of the second-order optical susceptibility χ(2) was monitored as a function of pressure using second harmonic generation. In each system, the observed decay of χ(2) was represented by a stretched exponential equation from which the decay time τ0 and decay distribution width βKWW were determined. For each dopant molecule, the decrease in activation volume with the increasing size of the polymer host's alkyl side group and the pressure dependence of βKWW were indicative of partial coupling between chromophore rotation and the glassy β relaxation dynamics of the polymer host. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1013-1024, 1998
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
