Studies on Miscibility of Polymers

I. Precipitation Behavior from Common Solvent Solutions

Abstract

Turbidities of suspensions produced by adding precipitant to common solvent solution of two polymers were measured and the difference in the precipitation behavior due to the miscibility of polymeric components was elucidated. Polymers used in combination are polymethyl methacrylate (PMMA), polymethyl acrylate (PMA), nitrocellulose (NC), cellulese butylate (CB), polyvinyl chloride (PVC) and nitrile rubber (NR). Precipitation behavior of a component of non-miscible polymers (PMMA-PMA and PMMA-CB) is not so much affected by the presence of the other one; that is, two compcnents precipitate rather independently. On the other hand, in the case of miscible polymers (PMMA-NC, PMA-NC and PVC-NR), they precipitate simultaneously, and moreover, for PMMA-NC and PMA-NC systems, they precipitate by addition of smaller quantity of precipitant than for each component. These behaviors suggest the presence of strong interaction between NC and PMA or NC and PMMA.