FLUORESCENCE STUDIES OF POLYMER BLENDS - ANCHORING STABILIZER CHAIN IN NONAQUEOUS DISPERSIONS

Non-aqueous dispersions of poly(vinyl acetate) stabilized by a surface layer of poly(2-ethylhexyl methacrylate) (PEHMA) were prepared. sensor the recipe for particle synthesis, using as a stabilizer a copolymer of EHMA containing a small amount of either phenanthrene (Phe) or pyrene (Py) groups. These fluorescent labels permit us to assess different aspects of stabilizer chain morphology and dynamics. In the particles labeled with Phe groups, the ability of oxygen to quench Phe fluorescence is used as a monitor of O//2 sorption at the stabilizer-particle interface. In these experiments, information about the location of the labels and the PEHMA polymer is obtained. In the particles labeled with Py, pyrene self-quenching and excimer formation serves as a sensor of conformational and mobility changes in the PEHMA polymer upon anchoring in the particle.