Diglycidyl ether of bisphenol a

Ramie fabric was purchased from Hunan Huasheng Dongting hemp Industry Co., Ltd., the areal density is 135.1 g/m², and 3,4-dihydroxybenzaldehyde, aniline, polyethyleneimine (PEI), and 4,4′-diaminodiphenylmethane (DDM) were obtained from Aladdin Reagent Co., Shanghai, China. The 9,9-Bis(4-aminophenyl)fluorene was purchased from Shenzhen Star Kaiyue Biotechnology CO., Ltd., Shenzhen, China. Diglycidyl ether of bisphenol A (trade name DER-331, abbreviated as DGEBA, viscosity less than 1 Pa·s) with epoxy value around 0.51–0.53 mol/100 g was purchased from Dow Chemical Company. The 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, 98%) was bought from Guizhou Yuanyi Mining Group Co., Ltd., Guiyang, China. Tetrahydrofuran and ethyl alcohol was acquired from Sinopharm Chemical Reagent Co., Ltd., Shanghai, China. All the materials were used as received without any further purification.

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 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.