Fluorescence method for studying latex film formation

Abstract

Latex films were prepared separately by annealing pyrene $(P_y)$ labeled poly (methyl methacrylate) (PMMA) particles above the glass transition temperature. The variation in the direct fluorescence emission of excited pyrene from labeled latex films was monitored as a function of annealing temperature. Void closure temperature $(T_c)$ and time $(t_c)$ were determined at the point where the fluorescence emission intensity becomes maximum. Below this point, increase in fluorescence intensity $(l_{op})$ against temperature was used to determined the activation energy for viscous flow $(Delta Hcong47 kcal/mol)$. Decrease in idf above the void closure temperature was used to produce the backbone activation energy $(Delta Econg47kcal/mol)$ for the interdiffusing chains.