▎ 摘　　要

Crosslinking polyurethane-based solid-solid phase change materials with in situ reduced graphene oxide (GO) sheets were fabricated by a facile solvothermal treatment. GO sheets could give their full play to the enhancement of the system, which can endow the system with outstanding form-stability over 100 degrees C for the synergistic effect with hexamethylene diisocyanate biuret, and remarkable light-thermal conversion efficiency up to 78.7% due to the simultaneous in situ reduction of GO. The phase change enthalpy increases to 127.3 J/g from 86.8 J/g with 3.8 wt% GO for the nucleation and alleviating effects in the system. Meanwhile, the system has improved thermal stability and favorable thermal reproducibility. Therefore, the synthesized materials with comprehensive properties would be perspective to be used in energy storage devices such as solar energy collector system.