Interface Stability of Microencapsulated-Paraffin Filled Epoxy Composites: Effect of Methylation on Melamine–Formaldehyde Shell Material

Abstract

Microcapsules containing phase change materials (microPCMs) can be filled in polymeric matrix forming smart temperature-controlling composites. The aim of this study was to investigate the composite interface stability of microPCMs/epoxy composites. Paraffin was applied as the phase change materials. Methanolmelamine-formaldehyde (MMF) and melamine-formaldehyde (MF) were both used to form the shell of microPCM by in-situ polymerization. The investigation focused on studying the effect of methylation and interface stability. The MF-and MMF-prepolymers were both successfully used to fabricate microcapsules with globe shapes and smooth surface. Thermal stability tests proved that the MMF-shell microPCMs/epoxy composites had a better interface stability than MF-shell microPCMs/epoxy composites. Mechanical properties also indicated that the MMF-shell microPCMs/epoxy composites had less tensile strength destruction after the thermal treatment. These results mean the MMF-resin enhanced the interface bonding stability though improving the interface molecule entanglement. As the MMF molecular has relative flexible ability and can adjust its conformation under change in environmental conditions, the interface will decrease the microstructure defects such as cracks, gaps and debonding.

The influence of microencapsulated phase change material (PCM) characteristics on the microstructure and strength of cementitious composites: Experiments and finite element simulations

“…The FTIR spectra shown in Figure 3 are similar to those reported for other microencapsulated PCMs [33,37,43]. The intensity of the peak at 1730 cm -1 corresponding to the carbonyl group is much higher for PCM-E as observed in Figure 3(a), which represents a stronger bond between the associated carbonyl groups.…”

“…A larger core content is generally likely to result in poor formation of the shell walls and thus decreases the stability of the microcapsules [42]. However, the results in the subsequent sections in this paper suggest that for PCM-E, this problem has been overcome, possibly through chemical modification of MF [40,43]. Fourier Transform Infrared (FTIR) spectra of both the PCMs are shown in Figure 3(a).…”

Investigation of the Self-Healing Behaviors of Microcapsules/Bitumen Composites by a Repetitive Direct Tension Test

“…No interface debonding emerged between microcapsules and bitumen after a mixture and a temperature change. An interphase region is comprised of polymer molecules that are bound at the filled particles surface, and they exhibit unique physical and chemical properties [ 21 ].…”

Mechanical and thermal characterisation of multifunctional composites incorporating phase change materials

“…[6][7][8] In order to develop FRP-incorporated multifunctional composites, it is necessary to fully understand the inclusion effect of phase change materials with respect to the structural and thermophysical properties of composite laminates. Although several studies have reported on the inclusion effect of different microcapsules in polymer matrices, [9][10][11][12][13][14] the failure mechanisms associated with the presence of microencapsulated phase change materials (micro-PCMs) in FRP composites have not been broadly addressed in the open literature. This paper reports an experimental study on incorporating micro-PCMs in glass-epoxy composites and characterising their mechanical and thermal properties.…”