Fast transient fluorescence technique (FTRT) for studying dissolution of polymer glasses

Abstract

The fast transient fluorescence technique (FTRT) was used for studying the swelling and dissolution of a glassy polymer formed by free-radical polymerization of methyl methacrylate (MMA). Anthracene (An) was introduced during polymerization as a fluorescence probe to monitor swelling and dissolution. Swelling and dissolution processes of disc-shaped poly(methyl methacrylate) (PMMA) glasses in a chloroform-heptane mixture were monitored by measuring the fluorescence lifetimes of An from its decay traces. A method is developed for low quenching efficiencies for measuring lifetimes, τ, of An, and it was observed that τ values decreased as the dissolution process proceeded. Desorption, D, and mutual diffusion, D m , coefficients of An molecules were measured during dissolution of PMMA and found to be around 5.4 × 10 -6 (cm 2 /s) and 2.2 × 10 -5 (cm 2 /s), respectively.