CHARACTERIZATION OF THE MISCIBILITY OF POLY(BUTYL METHACRYLATE) WITH A NONYLPHENOL ETHOXYLATE SURFACTANT AND WITH VARIOUS POLY(ETHYLENE GLYCOL) OLIGOMERS

Previous experiments from the Winnik group (e.g., Macromol. Rapid Comm un. 1995, 16, 861) have established that several nonylphenol ethoxylat e surfactants were miscible with poly(butyl methacrylate) (PBMA) latex films at 90 degrees C, and act as plasticizers to accelerate polymer diffusion rates in the films. Here we turn our attention to the questi on of miscibility at room temperature. Using modulated DSC, we show th at a nonylphenol ethoxylate (NP-20, with 20 ethylene oxide units, EO20 ) has only limited (ca. 2 wt %) miscibility with high molecular weight PBMA latex films at room temperatures and that corresponding poly(eth ylene glycol) (PEG) oligomers EOx (x = 10, 20) have even lower miscibi lity. Miscibility is detected as a decrease in the glass transition te mperature of the polymer; and immiscibility, as a melting endotherm of the surfactant component. In addition, we examine the influence of th e EOx oligomers on the polymer diffusion rate in PBMA latex films. Oli gomers larger than EO10 retard the rate of interparticle polymer diffu sion.