Nanomaterials Modified One-component Polyurethane Sealant

Nano-materials play an important role in the modification of polymer properties for it's unique properties. In this paper, several nanopaticles were surface treated and added to the one-component polyurethane sealant as modifiers. The effect of the nanoparticles content on sealant performance was discussed. The main work are shown as follows:Nano-SiO2 was synthesized via Stober. It was spherical and well dispersed with the diameter of about 200nm in TEM photo. Silane coupler was used as surface modifier and there was a new peak at 2941cm-1 shown in the FTIR spectrum, which indicated that silane coupler has successfully connected with nano-SiO2. Attapulgite was purified and dispersed by using dispersant agent. The TEM photo showed that the content of impurity was reduced and the rob bundle become incompact. Silane coupler was used as surface modifier for attapulgite, and there were new peaks at 2929cm-1 and 2848cm-1 shown in the FTIR spectrum; Nano-montmorillonite was intercalated by intercalating agent.The XRD pattern showed that diffraction peaks of (001) shifted to the small-angle direction. There were new peaks at 2925cm-1 and 2843cm-1 shown in the FTIR spectrum. TG curve showed that the content of intercalating agent was about 9.8%.Polyurethane prepolymer was prepared by polymerization of TDI and polyether polyol. The influences of the isocyanate content,reaction temperature and catalyst amount were discussed on prepolymer performance. The results showed that the optimal reaction temperature was 80℃, appropriate amount of catalyst was around 0.1%, the isocyanate content which determined the end of the reaction was 3.5% and the entire process of the reaction time was 4h.Several nano-materials which had been surface treated were added as modifier in the one-component polyurethane sealant synthesis. The influences of the content of different nanomaterials were discussed on sealant performance. The results showed that:the surface drying time of sealant prolonged with the content of the nano-materials increased; Nano-montmorillonite performed best in the modification of the hardness. It reached the highest number 58 when the content of Nano-montmorillonite was about 10%; The elongation at break of sealant perform best when the content of nanoparticles was about 5%, but after that it decreased gradually with the content increasing; Attapulgite performed best in the modification of the tensile strength. The tensile strength of sealant reached 10.3MPa when the content of attapulgite was about 5%.