Investigation of PEG/mixed metal oxides as a new form-stable phase change material for thermoregulation and improved UV ageing resistance of bitumen.

The form-stable phase change material (PCM), polyethylene glycol (PEG)/ZnMgAl-mixed metal oxides (MMO), is prepared as a performance-enhancing additive of bitumen. In PEG/MMO PCM, PEG exhibits the phase-change function while ZnMgAl-MMO acts as the support carrier to prevent leakage of liquid PEG during phase transition. The properties of PEG/MMO PCM were analysed by XRD, SEM, FTIR, DSC, TG and UV-vis spectrophotometry. The results showed that the maximum PEG confined by MMO could be 65% and 65PEG/MMO PCM exhibited good thermal and chemical stability, sufficient phase change enthalpy and excellent UV absorption properties. Furthermore, the temperature regulation and UV ageing resistance of PEG/MMO PCM modified bitumen was evaluated by the thermal storage and release test and accelerated UV aging test. As a new type of performance-enhancing additive, PEG/MMO PCM is expected to be effective in regulating extreme temperature and resisting UV aging of bitumen and thus significantly extending the service life of bitumen pavement.