Diffusion of Camphorquinone in Uniaxially Drawn Polycarbonate Films

摘要

Employing the laser induced holographic grating relaxation technique, we havemeasured tracer diffusion coefficients of a photochromous dye, camphorquinone (CQ), in uniaxially drawn polycarbonate films as a function of stretch ratio. Anisotropy in the tracer diffusion coefficient has been observed with D greater than D by at least a factor of 4 for the film stretched to the stretch ratio delta = 2.3. The diffusion coefficient along the direction of stretch D increases significantly with increasing delta, whereas D decreases slightly with increasing delta. The stretch ratio dependence of D and D is interpreted according to a modified free volume theory. The strain rate and stretch temperature dependence of the anisotropic tracer diffusion coefficient has also been investigated.