4 4 diaminodiphenyl sulfone dds

The thermosetting binder was diglycidyl ether of bisphenol A (D.E.R. 330, Dow Chemical, Midland, MI, USA) containing 180.5 g/mol-eq epoxy groups. The hardener was 4,4′-diaminodiphenyl sulfone (DDS, Sigma-Aldrich, Steinheim, Germany) with an amine group content of 62.1 g/mol-eq. The weight ratio of epoxy resin to hardener was stoichiometric (74.4/25.6 wt.%/wt.%).
High melting point vegetable oils were used as PCMs: refined palm oil from Malaysia (T_m = 36 °C) and refined, bleached, and deodorized coconut oil from Thailand (T_m = 21 °C), which were purchased at a local market. Palm oil contains mostly triglycerides of oleic and palmitic acids [56 (link)], while coconut oil belongs to the lauric group of vegetable oils and differs by its sharp transition from solid to liquid states within a narrow temperature range [57 (link)].
Blends of epoxy resin, hardener, and one of the vegetable oils were prepared by mechanical mixing on a magnetic stirrer at 60 °C. The oil content in the resin/hardener mixture was 0, 5, 10, or 20 wt.%. The blends were cured at 180 °C for 3 h.

The DGEBA (Bisphenol A diglycidyl ether), the 4,4′-diaminodiphenylsulfone (DDS) were purchased from Sigma-Aldrich. Bentonite was purified according to a standard procedure^{64 (link)} resulting in ∼80-μm-sized bentonite (B). The cationic exchange capacity (CEC) was equal to 101.9 meq/(100 g of clay). Fe₃O₄ nanopowder (Sigma Aldrich, 97% purity, 50–100 nm), N-phenyl-p-phenylenediamine (Acros, 98% purity), isopentyl nitrite (Alfa Aesar, purity 97%), ammonium persulfate (APS, Acros, 98% purity), and nitric acid (Carlo Erba, 60% purity). Aniline (Aldrich, 99.5% pure) was purified and stored at low temperature before usage. Distillated water for cleaning and dilutions was used throughout.

The thermosetting binder was diglycidyl ether of bisphenol A (D.E.R. 330, Dow Chemical, Midland, MI, USA) containing 180.5 g/mol-eq epoxy groups. The hardener was 4,4′-diaminodiphenyl sulfone (DDS, Sigma-Aldrich, Steinheim, Germany) with an amine group content of 62.1 g/mol-eq. The weight ratio of epoxy resin to hardener was stoichiometric (74.4/25.6 wt.%/wt.%).
High melting point vegetable oils were used as PCMs: refined palm oil from Malaysia (T_m = 36 °C) and refined, bleached, and deodorized coconut oil from Thailand (T_m = 21 °C), which were purchased at a local market. Palm oil contains mostly triglycerides of oleic and palmitic acids [56 (link)], while coconut oil belongs to the lauric group of vegetable oils and differs by its sharp transition from solid to liquid states within a narrow temperature range [57 (link)].
Blends of epoxy resin, hardener, and one of the vegetable oils were prepared by mechanical mixing on a magnetic stirrer at 60 °C. The oil content in the resin/hardener mixture was 0, 5, 10, or 20 wt.%. The blends were cured at 180 °C for 3 h.