Preparation Of POSS/ Polymers Composites By Emulsion Polymerization And Research On Its Properties

Five kinds of multifunctional polyhedral oligomeric silsesquioxane (POSS) were synthesized. Meanwhile, a new composite OVPOSS-PS was prepared by emulsion polymerization. After the incorporation of POSS molecule, the thermal properties of the composites were also studied. The main content of this dissertation is as follows:1. The synthesis of POSS and POSS/polymers composites were reviewed, and the thermal properties, mechanical properties, flame retardancy and oxidation resistance properties were summarized after POSS molecule was introduced into polymer matrixs.2. Five kinds of multifunctional polyhedral oligomeric silsesquioxane (POSS) were synthesized through hydrolytic polycondensation of silsesquioxanes. The structures of POSS were characterized by FTIR, NMR, and XRD.3. A new composite OVPOSS-PS was prepared by batch emulsion polymerization. The structure of OVPOSS-PS composite was well characterized by FTIR, NMR and XRD. The results indicated that OVPOSS could be incorporated into the PS matrix by the polymerization. TEM images showed that the composite particles were in regular shape with a uniform size and have a core-shell structure. Results of XRD revealed that POSS was well dispersed in the composites. The thermal properties were investigated by DSC and TGA. The data indicated that the incorporation of POSS can apparently improve the thermal stability of PS.4. OVPOSS-PS composites were also prepared by seed emulsion polymerization. The structure and the composition of OVPOSS-PS composites were well characterized by FTIR, 1H NMR and XRD. The results proved that OVPOSS was successfully synthesized and further confirmed the incorporation of POSS into the PS matrix. TEM image showed that the OVPOSS-PS composite paticles had a uniform size of about 300 nm and OVPOSS was well dispersed in the composites. The thermal properties were investigated by DSC and TGA. The data indicated that the Tdec, Tg of OVPOSS-PS composites were 65 oC, 8 oC higher than these of the pure PS respectively, which was mainly due to the incorporation of POSS unit.