Synthesis and Properties of Dynamic Crosslinking Polyurethane/PEG Shape-Stable Phase Change Materials Based on the Diels–Alder Reaction

Abstract

Phase change materials (PCMs) can absorb and release energy while keeping the temperature constant; hence, they play a crucial role in the thermal management field. Shape-stable phase change materials (SSPCMs) were synthesized by chemical crosslinking to address the liquid leakage problem of solid−liquid phase change materials (SLPCMs) during the phase change process. However, the abandoned SSPCMs cannot be reused and recycled, which seriously restricts their practical application. Herein, a polyurethane network containing Diels−Alder bonds was used as the enclosure compound to obtain the encapsulation of polyethylene glycol (PEG), and then, the chemical structure, crystallization behavior, and phase transition ability of SSPCMs were systematically investigated. The results showed that the SSPCMs-3 sample (300 wt % PEG) had the best comprehensive performance, an enthalpy value of 171.7 J/g, and no leakage at 80 °C for 1 h. Moreover, the structure, crystallization behavior, and phase transition ability of SSPCMs could also basically remain unchanged after multiple thermal cycling and reprocessing.

PEG-crosslinked O-carboxymethyl chitosan films with degradability and antibacterial activity for food packaging

“…2 a) disappeared 41 , accompanied by the presence of a new peak at 2266 cm −1 which vested in the typical absorption of –NCO groups. The peaks at 3332, 1717, and 1536 cm −1 should belong to the –NH–, amide, and C=O absorption in the newly formed urethane groups, respectively 42 . The analysis indicated that the terminal –OH groups of PEG were completely consumed and the –NCO groups were successfully introduced to the end of the PEG chain.…”

A critical review of polymer support‐based shape‐stabilized phase change materials for thermal energy storage applications

“…Lin et al developed SSPCM using PU as supporting material and PEG as PCM to systematically examine the chemical composition and thermal storage capabilities. 25 The results revealed that SSPCM showed remarkable performance, with an enthalpy of 171.7 J/g without any leakage. Additionally, the structure, thermal, and chemical behavior of SSPCM remained unchanged after multiple thermal cycles and reprocessing.…”

“…36 By incorporating waste stone fragments and employing low-toxic, low-flammability polymers in SSPCM production, there is an advancement towards aligning with the principles of a circular economy and diminishing the ecological footprint of manufacturing processes. 25 Therefore, encapsulating PCMs within waste plastics offers a dual benefit of mitigating plastic waste pollution while enhancing the energy storage capabilities of the materials. 34 The environmental impact of producing SSPCMs can be evaluated through life cycle analysis frameworks, which examine the ecological footprint at different stages of the product's life cycle, such as raw material extraction, manufacturing, usage, disposal, and recycling options.…”

“…Some studies have investigated employing waste thermoplastics as encapsulation materials, potentially lessening their ecological footprint and aiding in reducing waste and conserving resources 36 . By incorporating waste stone fragments and employing low‐toxic, low‐flammability polymers in SSPCM production, there is an advancement towards aligning with the principles of a circular economy and diminishing the ecological footprint of manufacturing processes 25 . Therefore, encapsulating PCMs within waste plastics offers a dual benefit of mitigating plastic waste pollution while enhancing the energy storage capabilities of the materials 34 …”

A form-stable phase change material based on intermolecular hydrogen bonding with a high chemical recycling rate

“…The polyurethane was recycled, but MDI, PTMG, furfuryl, and TMI could not be restored. 32 Lei et al prepared a recyclable PEG-based SSPCM through dynamic ionic crosslinking between grafted PEG and zinc acetate. PEG reacted with pyromellitic dianhydride (PMDA) to form the grafted PEG.…”