Morphology and Emulsification of Poly(<i>N</i>-2-(methacryloyloxy) ethyl pyrrolidone)-<i>b</i>-poly(benzyl methacrylate) Assemblies by Polymerization-Induced Self-Assembly

In this work, a series of amphiphilic diblock copolymers poly(<i>N</i>-2-(methacryloyloxy) ethyl pyrrolidone)-<i>b</i>-poly(benzyl methacrylate) (PNMP _<i>m</i> -<i>b</i>-PBzMA _<i>n</i> ) were developed by the dispersion polymerization method in ethanol. The polymerization-induced self-assembly (PISA) behaviors were studied systematically, and a comprehensive structure-property relationship was also established. Two distinct PISA tendencies were observed, which was mainly depended on the polymerization degree <i>m</i> of PNMP segment. When <i>m</i> is small such as 39 and 55, morphological transitions from spherical to vesicle-like assemblies via wormlike ones upon increasing <i>n</i> commonly happen regardless of the solid content. Alternatively, spherical assemblies became the sole morphology for PNMP₆₄-<i>b</i>-PBzMA _<i>n</i> block copolymers because of the excellent solvophilicity of the PNMP₆₄ segment. Attributing to the amphiphilicity of PNMP _<i>m</i> -<i>b</i>-PBzMA _<i>n</i> block copolymers, PNMP _<i>m</i> -<i>b</i>-PBzMA _<i>n</i> assemblies by PISA are a type of excellent Pickering emulsifiers. These assemblies prefer to stabilize O/W Pickering emulsions as confirmed by the confocal laser scanning microscopy method, and the effects of polymerization degree of PBzMA segment or morphologies of PNMP _<i>m</i> -<i>b</i>-PBzMA _<i>n</i> assemblies are finite.