Visualizing the formation process of interfacial polymerized (Co)polyarylate films by an optical three-dimensional microscope

Abstract

Due to the complexity and rapidity, the formation process of interfacial polymerized (IP) films is difficult to be observed. Here, a visualized technique, optical three-dimensional microscope, is used to in situ investigate the formation process of (co)polyarylate film. As the polymerization time increases, the film surface shows varied morphologies which is mainly controlled by the formation rate of cross-linked film and the release rate of mixed gases, and tri-functional acyl chloride facilitates to form a homogeneous film comparing to bi-functional acyl chloride. The addition of phase transfer catalysts (PTCs) can accelerate the diffusion of monomer, which has two opposite effects: one is increasing the releasing rate of gases, the opposite is facilitating the increase of the cross-linking degree that inhibits the gases release. Moreover, different type of PTCs affects the film morphology in a different way. This study sheds light on the fundamental understanding of the formation process of IP films.