ISSN:
0887-6266
Keywords:
block copolymers
;
molecular diffusion
;
Forced Rayleigh scattering
;
free volume
;
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Forced Rayleigh scattering was used to investigate the diffusion of a photoreactive dye molecule in two homogeneous poly(styrene-b-isoprene) (SI) diblock copolymers with overall molecular weights of approximately 2000. Although diffusion rates were intermediate to TTI transport in homopolymer polystyrene (PS) and polyisoprene (PI), system dynamics appear to be largely dictated in each case by the PI block. The size of the polymer jumping unit, on the other hand, is evaluated from a free-volume analysis of the data, and is found to be governed predominantly by the PS component of the copolymer. The mechanism for tracer diffusion in low-molecular-weight block copolymers appears analogous to transport in a high molecular weight SI diblock copolymer (Mn = 13,600) that has been solvated sufficiently in toluene to be microstructurally disordered. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1739-1746, 1998
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
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