Bio-based recyclable Form-Stable phase change material based on thermally reversible Diels-Alder reaction for sustainable thermal energy storage

Polymer-based form-stable phase change materials (FPCMs) have attracted much attention due to their excellent shape stability and facileness, low-energy-consumption preparation. However, bio-based recyclable phase change energy storage materials (PCMs), crucial for reducing pollution and sustainable energy storage, have not yet been prepared. Herein, we prepared a novel bio-based recyclable PCM (DGEM-18/FA/MA/xBW), in which a novel epoxy resin (DGEM) was synthesized by using bio-based magnolol and epichlorohydrin, bio-based 2-Furanmethanamine (FA) and C36-alkylenediamines bismaleimide (MA) were used to construct a reversible crosslinked network based on epoxy-amine ring opening and Diels-Alder (D-A) reactions as the supporting frame. And 1-Octadecanethiol (ODT) and bio-based beeswax (BW) with phase change property were introduced into this supporting frame by grafting on the C=C of Magnolol via "thiol-ene" click reaction and physical blending, respectively. The D-A and rD-A reactions proceed at the temperature below 80 celcius and above 120 degrees C, respectively, which provides recyclability of the crosslinked network. The ODT and beeswax provide phase change latent heat up to 119.1 J/g for the sample DGEM-18/FA/MA/1.1BW. Furthermore, taking DGEM-18/FA/MA/0.4BW as an example, its shape memory performance has been explored, as well as its potential applications in recyclable thermal management coatings. To the best of our knowledge, this is the first report on the preparation of biobased recyclable FPCMs.