Effect of annealing on the phase structure and the properties of the film formed from P(St-co-BA)/P(MMA-co-BA) composite latex

Composite latex of P(St-co-BA)/P(MMA-co-BA) was prepared by two-step semi-continuous emulsion polymerization under starved conditions. Optical properties, water resistance and heat aging process of the film formed by the composite latex were examined. It was revealed that annealing temperature played an important role on the structure of the composite latex film. The surface of the film prepared at room temperature was very rough. Many micro-cracks were observed both on the surface and inside of the film. Increase of annealing temperature assisted film formation. There was a critical temperature at which the film properties, such as water resistance and transparency, were significantly improved. However, it was worth to note that phase rearrangement had occurred when the annealing temperature was higher than critical temperature. Micro-pinholes and micro-cracks were detected on the surface of the film. Meanwhile, the properties of the film, such as transparency and water adsorption, became remarkable deteriorated.

Phase rearrangement had occurred in the composite latex film when the annealing temperature was higher than critical temperature. Micro-pinholes and micro-cracks were detected on the surface of the film.Figure optionsDownload high-quality image (76 K)Download as PowerPoint slide