▎ 摘　　要

Graphene oxide (GO) is chemically tagged with polyurethane matrix and thereby prepared a polymer nanocomposite gel and compared its property development with respect to physically GO mixed polyurethane composite. Very high gelation rate is observed for GO tagged polymer along with its formation at higher temperature as compared to physical mixture. The thermal (gel melting and solvent retention power) and mechanical stabilities have significantly been improved in chemically tagged nanocomposite gel. The interaction between GO and polyurethane, responsible for improved properties, has been verified through spectroscopic measurements, from the shifting of peak position. The detail rheological measurements such as frequency sweep, steady shear, constant shear and stress relaxation analyses are performed to understand the effect of chemical tagging of GO with the polymer chains. The storage moduli (G ') show almost parallel to x-axis with increasing frequency for the nanocomposite gels of chemically tagged species while it slightly increase, especially at higher frequency, in pure polyurethane gel. The gel strengths are found to be 88, 560 and 12844 Pa for pure PU, physical and chemical gel, respectively. The viscosity of chemically tagged nanocomposite gel is significantly higher as compared to the pure, and physically tagged polymer gels (both the steady and dynamic state). Nanocomposite gels exhibit better elastic properties as evident from quite stable relaxation moduli even at longer time as opposed to pure polymer gel where considerably sharp decrease of modulus is observed. However, the chemical tagging of GO improves the properties of the polymer gel for their wider applications.