Prediction of mutaual diffusion coefficients for acrylic polymer + organic solvent systems using free volume theory

摘要

In the polymer manufacturing and processing, it is very important to remove efficiently trace amounts of volatile substances (solvent or monomer) remaining in the polymer products because they decrease the quality of polymer products and hurt the environment and human health. To design rational devolatilization equipments, mutual diffusion coefficients for a given polymer + solvent system are essential as fundamental data. Since there exists a variety of combinations of polymers and solvents, it is very difficult to obtain them for the system concerned. Therefore, a method to predict the mutual diffusion coefficients is desired. Kobuchi et al. [1-3] have measured the mutual diffusion coefficients for acrylic adhesive (random copolymer consisting of 2-ethylhexylmethacrylate, dodecylmethacrylate and 2-ethylhexylacrylate with a mole ratio of 8:1:1) + acetate ester (methyl acetate, ethyl acetate and propyl acetate), acrylic adhesive + ketone (acetone, ethyl methyl ketone and methyl propyl ketone) and poly-2-ethylhexylmethacrylate + ketone systems using a sorption apparatus with a quartz spring. It is noted that the free volume theory of Duda et al. modified by Iwai et al. is useful i predicting those multual diffusion coefficients. In this paper, the prediction performances of the free volume theory for those systems are reviewed.