Polyethylene glycol/polyvinyl butyral/graphene nanoplates as composite phase-change materials with high thermal conductivity

Composite phase-change materials (CPM) were prepared using polyethylene glycol (PG), polyvinyl butyral (PB) and graphene nanoplates (GP). PG is a phase-change material (PM), PB is used as supporting material, and GP is an additive with high thermal conductivity. The results of Fourier transformation infrared spectroscope (FT–IR) and X–ray diffractometer (XRD) show that there is no chemical reaction among the PB, PG and GP. The CPM was observed with a laminar structure by scanning electronic microscope (SEM). Differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and transient hot–wire conductivity meter were used to measure thermal performance of the CPM. The experimental results indicate that CPM3 has best thermal performance. The CPM3 containing 5 wt% GP has thermal conductivity of 2.04 W/(m⋅K), 8.87 times that of pure PG. The melting temperature and latent heat of the CPM3 are 58.75 °C and 147.81 J/g. Thermal cycling experiments demonstrate the CPM3 possesses good thermal reliability. Therefore, it has application prospects in solar energy utilization, building energy conservation and waste heat recovery.