Morphology control of zinc hydroxystannate microcapsules by sol-gel method and their enhanced flame retardancy properties for polyvinyl chloride composites

The aluminum hydroxide (ATH)/zinc hydroxystannate (ZHS) microcapsule was firstly prepared via sol-gel processing technique, and then melamine-formaldehyde resin(MF)/aluminum hydroxide(ATH)/zinc hydroxystannate (ZHS) microcapsule was secondly prepared. Their structures were characterized by fourier-transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, scan electron microscopy and laser size distribution analysis techniques. The results indicated that the successful formed and controlled of ATH/ZHS and MF/ATH/ZHS microcapsules. In addition, the effect of these microcapsules on flame retardancy and smoke suppression properties of poly (vinyl chloride)(PVC) composites was evaluated. The results revealed that ATH/ZHS and MF/ATH/ZHS microcapsules had improved the flame retardancy, smoke suppression properties of PVC composites, which behaved as a very good flame retardant and smoke suppressant. The single layer and double layers microcapsules (ATH/ZHS microcapsule and MF/ATH/ZHS microcapsule) have been synthesized via sol-gel processing technique and their enhanced flame retardancy, smoke suppression properties for polyvinyl chloride composites.