Preparation of Polyacrylate Emulsion with High Adhesion Properties by Adding Modified Silica Sol

Polyacrylate emulsions can be used as adhesives. However, low water resistance and insufficient adhesion have restricted their application. In this study, polyacrylate/silica composite adhesives were prepared by emulsifier-free polymerization. Fourier transform infrared spectroscopy results confirm that modified silica is successfully introduced into the emulsion. Thermogravimetry and differential scanning calorimeter indicate that with the increase of modified silica sol content, the thermal stability of the composite film is improved. When modified silica sol content increases from 0 to 8 wt %, the water contact angle increases from 74° to 98°, and the water sorption rate decreases from 16.5 to 7.8%. Moreover, with the addition of modified silica sol, the peel strength and tack of the modified latex changed slightly. Still, the shear strength on paper materials ranges from 148 min to over 1000 min when the content of modified silica sol reaches 8 wt %. The results show that adding modified silica sol can enhance the adsorption interaction between adhesive and paper material, effectively improving latex adhesive properties.