Development of PTMEG/MDI-based solid-solid phase change materials for asphalt pavements deicing

Adding phase change materials (PCMs) to asphalt pavements can effectively reduce temperature sensitivity and delay snow and ice accumulation. This study aims to develop solid-solid phase change materials (SSPCMs) for asphalt pavements, with a focus on winter road de-icing. First, the suitability of polyethylene glycol (PEG) and polytetramethylene ether glycol (PTMEG) with varying molecular weights as soft segments was systematically evaluated based on phase change performance, thermal stability, phase change cycling stability, and specific heat capacity. SSPCMs were synthesized using a two-step solution polymerization method, with successful synthesis confirmed by FTIR analysis. The influence of different soft-to-hard segment ratios on phase change performance was also examined. PTMEG2000 exhibited excellent performance, with an exothermic phase change temperature range from 8.5°C to -1.2°C and an enthalpy of 94.3 J/g. Its thermal decomposition onset temperature was 266.05°C, and its performance remained stable after 20 thermal cycles. The incorporation of hard segments led to a reduction in both phase change enthalpy and the initial phase change temperature. At a molar ratio of 4,4′-diphenylmethane diisocyanate (MDI) to PTMEG2000 of 2.4:1, the phase change temperature range was 4.1°C to -5.1°C, with an enthalpy of 37.1 J/g, demonstrating great potential as a de-icing material for roads in cold climates.