Crosslinked polymer networks of poly(ethylene glycol) (PEG) and hydroxyl terminated poly(dimethyl siloxane) (HTPDMS) as polymeric phase change material for thermal energy storage

With an aim to prepare phase change material (PCM) as self-sustaining film from poly(ethylene glycol) (PEG) having reduced hydrophilicity, cross-linking of PEG and hydroxy-terminated poly(dimethyl siloxane) (HTPDMS) was done by using tetraethyl orthosilicate (TEOS) as a cross-linking agent. Following the confirmation of the crosslinked polymer using FTIR and ¹³C-solid state NMR, the crystallization properties were studied using X-ray diffraction and polarized optical microscopy. DSC analysis indicated an increase in enthalpy with increasing concentration of PEG. The enthalpy of fusion and crystallization was observed to reach a maximum of 125 and 104 J g⁻¹ respectively. Contact angle of 89.5° has been achieved for polymer with highest concentration of HTPDMS. The material with lowest PEG concentration was film forming in nature. This material can be extensively used as a thermal energy storage material particularly, in smart packaging.