Esters dynamic scattering

Here, we focus on one class ofblock copolymers synthesized by this method polystyrene-6-poly(vinylperfluorooctanic acid ester) block copolymers (Figure 10.33). After describing the synthesis and characterization, we will treat some properties and the potential applications of this new class ofblock copolymers. The amphiphilicity of the polymers is visualized by the ability to form micelles in diverse solvents that are characterized by dynamic light scattering (DLS). Then the use of these macromolecules for dispersion polymerization in very unpolar media is demonstrated by the polymerization of styrene in 1,1,2-trichlorotrifluoroethane (Freon 113). 

The emulsion polymerization in the third step is carried out in the presence of a water soluble monomer, such as acrylic acid. The radicals formed by the photolysis of HMEM (Fig. 6.18b) on the surface start radical chain polymerization by a grafting-from technique (see Section 6.13.3) thus generating chains of poly(acrylic acid). The polymer chains remain bound to the surface by an ester bond which can be cleaved by hydrolysis to obtain the polymer for analysis. Thus the molecular weight of the bound polymer chains can be determined which gives their contour length Lc. The thiclcness L of the brush (Fig. 6.17) attached to the surface of the particles can be deduced from the hydrodynamic radius as measured by dynamic light scattering. 

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