LIU Gang, OU Baoli, ZHAO Xinxin, PENG Cairu

(School of Materials and Science Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China)

Abstract: The porous nano SiO₂ was prepared by one-pot hydrothermal synthesis. High strength polyurethane were synthesized with phthalic anhydride polyester polyol. Then, the polyurethane modified by graphene oxide was prepared by the reaction of isocyanate group at the end of the polyurethane with the hydroxyl group on the surface of graphene oxide. The porous nano SiO₂/graphene oxide modified polyurethane was prepared by the curing reaction using N-(2-cyanoethyl) diethanolamine and the porous nano SiO₂ as the chain extender and supplement. The infrared spectrometer (FTIR) results clearly showed that the high strength polyurethane modified by graphene oxide was successfully prepared. Scanning electron microscope (SEM) analysis indicated that the SiO₂ particles were uniform in size and about 80 nm in diameter. It was found that the graphene oxide modified polyurethane with 5wt.% porous nano SiO₂ has higher bond strength and elastic modulus under the synergistic effect of cyano chain extender. The maximum fracture strength and elastic modulus increased by 9.1% and 35.3%, respectively.
Key words: porous nano SiO₂; graphene oxide; modified polyurethane; coating materials