Fabrication and properties of chemically bonded polysilsesquioxane‐polyacrylate/silica hybrid latex films with high silicon content

Polysilsesquioxane‐polyacrylate/silica hybrid latexes (PSQ‐PAS) with high silicon content were prepared by directly mixing colloidal silica with polysilsesquioxane‐polyacrylate emulsion (PSQ‐PA), which was prepared through seeded emulsion polymerization using polymethacryloxypropylsilsesquioxanes as the core and polyacrylate (PA) as the shell respectively. The chemically bonded PSQ‐PAS thin films were obtained via sol‐gel process after addition of hydrophilic cosolvent to PSQ‐PAS emulsion and subsequent drying at room temperature. The effects of silica/PSQ‐PA ratio (w/w) on the film properties of hardness, optical property and thermal stability were investigated. Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to characterize the chemical composition and morphology of the resultant hybrid particles. DLS and TEM results indicated that both PSQ and PSQ‐PA particles had narrow size distribution and their average diameters were about 200 and 350 nm, respectively. Pendulum durometer, UV–vis spectroscopy, and thermogravimetric analysis (TGA) were used to characterize the hardness, optical property and thermal stability of PSQ‐PAS latex films. The results showed that the PSQ‐PAS films hardness increased with the increasing ratio of silica/PSQ‐PA, whereas the transmittance decreased slightly. TGA curves demonstrated PSQ‐PAS films displayed excellent thermal stability, and the residual silicon weight exceeded 30%. POLYM. COMPOS., 36:389–396, 2015. © 2014 Society of Plastics Engineers