Preparation and thermal properties of mineral-supported polyethylene glycol as form-stable composite phase change materials (CPCMs) used in asphalt pavements

Abstract

Three kinds of mineral-supported polyethylene glycol (PEG) as form-stable composite phase change materials (CPCMs) were prepared to choose the most suitable CPCMs in asphalt pavements for the problems of asphalt pavements rutting diseases and urban heat islands. The microstructure and chemical structure of CPCMs were characterized by SEM, FT-IR and XRD. Thermal properties of the CPCMs were determined by TG and DSC. The maximum PEG absorption of diatomite (DI), expanded perlite (EP) and expanded vermiculite (EVM) could reach 72%, 67% and 73.6%, respectively. The melting temperatures and latent heat of CPCMs are in the range of 52–55 °C and 100–115 J/g, respectively. The results show that PEG/EP has the best thermal and chemical stability after 100 times of heating-cooling process. Moreover, crystallization fraction results show that PEG/EP has slightly higher latent heats than that of PEG/DI and PEG/EVM. Temperature-adjusting asphalt mixture was prepared by substituting the fine aggregates with PEG/EP CPCMs. The upper surface maximum temperature difference of temperature-adjusting asphalt mixture reaches about 7.0 °C in laboratory, and the surface peak temperature reduces up to 4.3 °C in the field experiment during a typical summer day, indicating a great potential application for regulating pavement temperature field and alleviating the urban heat islands.

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

“…[5][6][7][8][9][10] In recent years, PCMs have been also applied in bitumen mixtures to enhance the temperature adaptability, which helps reduce the temperature damage of bitumen and extend the service life of bitumen pavement. 2,[11][12][13] Due to the unique features including suitable phase change temperatures, sufficient phase change latent heat, good phase change cycle stability and certain high temperature resistant properties, polyethylene glycol (PEG) has received considerable attention for application as a PCM. [14][15][16] However, the commercial application of PEG mainly faces two problems: low thermal conductivity and phase instability in melting state.…”

“…3 The direct incorporation of PEG in bitumen may increase the saturated content of bitumen, which will reduce the consistency of bitumen, resulting in higher penetration and lower ductility. 11 PEG-based form-stable PCMs which are oen composed of PEG and supporting materials have been developed to overcome the shortcomings. These PEG-based form-stable PCMs such as PEG/ silica, [17][18][19][20] PEG/diatomite, 21,22 PEG/gypsum, 23 PEG/montmorillonite, 24,25 PEG/porous carbons, [26][27][28] and PEG/polymers, [29][30][31][32] can keep the solid state even when PEG is undergoing solid-liquid phase transition above the melting temperatures.…”

Preparation and characterization of PEG/surface-modified layered double hydroxides as a new shape-stabilized phase change material

“…36 Previous researchers have studied mixing PCM into bitumen to change the thermo-physical characteristic of bitumen pavement using the latent thermal characteristic and temperature control function of PCM. 26 It has been found that aged bitumen led to the premature deterioration of pavement structure. 37 For improving the applicability of PCM in building materials and bitumen pavements, we propose a promising PCMs (the PEG/ surface-modied LDHs) to provide thermal regulation and improve aging resistance resulting in improved durability and extended service life.…”

“…The former group includes PEGnatural polymers, 15,16 PEG-acrylic polymers, 17 PEG-porous carbon materials (expanded graphite, activated carbon), [18][19][20] and PEG-hybrid organic systems. 21 The latter group is composed of PEG segments combining with different inorganic matter, such as silica, 3,4,7-9 montmorillonite, 22,23 diatomite, [24][25][26] gypsum and clays.…”

A Study on Modified Bitumen with Metal Doped Nano-TiO2 Pillared Montmorillonite

“…Therefore, the montmorillonite can be combined with the nano-materials to allow the nanoparticles to enter into the montmorillonite layer to form a pillared modified montmorillonite. This method is conducive to enlarging the interlayer spacing of montmorillonite, forming an exfoliated structure in the organic polymer materials, increasing the surface area of the materials and improving the catalytic performance and interlayer cation exchangeability of the materials [15,16].…”