High thermal reliability melamine resin phase change microcapsules based on chain extender modification: design, preparation and application evaluation of thermal insulation coatings

Abstract

Architectural coatings containing phase change microcapsules are promising for building energy conservation and other applications, but their limited thermal reliability hinders broader use and development. In this study, a modified melamine resin phase change microcapsule with enhanced stability and high heat storage capacity was designed and prepared via in-situ polymerization. The core material was 28^# paraffin, the wall material was methyl etherified melamine resin prepolymer (MMF), and the chain extenders were tetraethylenepentamine (TEPA) and polyetheramine (D230). The chemical structure, surface morphology, melt permeability, and thermal stability of the microcapsules were characterized and analyzed. The results indicated that the optimal performance of the microcapsules was achieved under the following conditions: a reaction temperature of 65 °C, a core-wall ratio of 1.5:1, and a modifier ratio of TEPA: D230 = 1:1.5. The product appeared as a powder, with a core material content of 86.25%, a phase change enthalpy of 97.21 J/g, and a 50.03% reduction in melt permeability. The microcapsules also exhibited high thermal stability. The coating containing 12.5% microcapsules demonstrated the best overall performance. In a simulated indoor environment, the modified coating system prolonged the cooling time from 35 °C to 20 °C by 37.02%.

Graphical Abstract