Effect of glutaraldehyde-chitosan crosslinked graphene oxide on high temperature properties of SBS modified asphalt

Composite material using glutaraldehyde (GA) cross-linked chitosan (CTS) and graphene oxide (GO-CTS-GA) was designed applying electrostatic interaction strategy under strong alkali environment. GO-CTS-GA was in turn applied to prepare styrene butadiene styrene (SBS) GO-CTS-GA/SBS composite modified asphalt (MA)_binder. The effect of GO-CTS-GA on the physical properties of SBS modified asphalt binder was investigated and its mechanism of action was analyzed. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy tests confirmed the retainment of GO flakes microscopic dimensions while compensating for the chemical structural defects and mechanical property damage of GO. The results of dynamic shear rheometer and multi-stress creep recovery tests indicated that the GO-CTS-GA/SBS-MA binder exhibited better viscosity performance and elasticity performance, rutting resistance and high temperature thermal stability. At 64 °C, the loss modulus of 0.10 % GO-CTS-GA/SBS-MA was 29.5 % and 25.2 % higher than that of SBS-MA and GO/SBS-MA, respectively. SEM and TEM analyses of the four components of asphalt binder before and after modification revealed that the change of asphaltene microscopic morphology seriously affects the stability of asphalt colloidal system. Fourier transform infra-red analysis of the MA binder revealed that the change of saturation fraction and colloidal polarity by GO-CTS-GA is responsible for the dispersion and cross-linking of SBS chain segments in the asphalt binder phase. This study provides important reference information for nanomaterials to change the macroscopic mechanical properties by modulating the microstructure, physical and chemical properties of asphalt binder at the micro and nano-scale.