Reduction of solvent content in toluene-neoprene adhesives and in acetone-polyurethane adhesives

摘要

The desorption of toluene in a polychloroprene (neoprene)-toluene adhesive and in a commercial neoprene adhesive was studied in air at three different temperatures by monitoring the weight loss vs time. Similarly, the desorption of acetone in a polyurethane adhesive and in a commercial adhesive was also considered. The experimental weight variations are correlated with the solution of the second Fick law at non-steady state. As the volume is hghly reduced when the solvent is evaporated from the solvent-polymer mixture, the correlations obtained are discussed o the basis of the variation of the diffusivity with the solvent concentration, assuming that the product of the diffusivity and the polymer volume fraction to the power 2 is approximately constant. Apparent activation energies were obttained for the four adhesives used.