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The scalability and simplicity of the procedure makes PEG-CaCO SB 3 sb blends suitable for various applications in thermal management systems. The cover image by Prathamesh Ranjane, Madhura Deshpande, and Prashant S. Kulkarni depicts the study, which represents the first exploration of polymorphs of calcium carbonate (CaCO SB 3 sb ) as inorganic support for the development of shape stabilized phase change material. The presence of calcite, aragonite, and vaterite forms of CaCO SB 3 sb was confirmed using X-ray diffraction. [Extracted from the article]

Thermal storage cotton possessing solid-solid phase change properties was prepared by direct grafting of polyethylene glycol (PEG) on cotton fiber/cloth. Attempt has been made to characterize intermediates so that desired grafting could be obtained. The grafting was done by using urethane linkage and the grafted cotton was found to undergo solid-solid phase transition. The modified cotton was characterized by using Fourier transform infrared spectroscopy (FT-IR), C CPMAS, polarizing optical microscopy, differential scanning calorimetry (DSC) and thermogravimetry respectively. The DSC study revealed quite good storage effect of grafted cotton and the enthalpy of melting was found to be 55-59 J/g with a peak appearing at around 60 °C. During cooling scan, the crystallization peak appeared at around 38 °C. Further, thermogravimetric analysis confirmed good thermal stability up to 300 °C. Appreciable improvement of mechanical properties of cotton has been observed after grafting. The polarizing optical micrograph clearly showed change of morphology after grafting, i.e., the grafted PEG adhering to fiber surface. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Hybrid chemically modified PEG based polymeric PCM prepared for the first time. • Enthalpy of fusion of 125 J g−1 attained. • High contact angle of 89.5° achieved for highest concentration of HTPDMS. Abstract 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. [ABSTRACT FROM AUTHOR]

In this study, we have reported the synthesis of copolymers of poly(ethylene glycol) acrylate (PEGA) with methyl methacrylate (MMA) in various ratios which can be utilized as polymeric phase change materials (PCMs). The monomer reactivity ratio of PEGA copolymers was determined by Fineman-Ross method. The values of r 1 (PEGA) and r 2 (MMA) were found to be 0.8164 and 0.3371 respectively. The thermal analysis performed by DSC indicated high fusion enthalpy of 168 J·g −1 at 55 °C for the feed ratio of 40:60 of PEGA:MMA (Copolymer mole fraction of 76:24). The crystallization behaviour shows the presence of spherulites but of smaller size compared to PEG and with reduced crystallization ability. The results point out the capabilities of PEGA to function as an effective PCM which can be utilized for numerous thermal energy storage applications. [ABSTRACT FROM AUTHOR]

For efficient energy storage, hyperbranched (HB) architecture was adopted to prepare a series of HB polyurethanes via A2 + B3 approach with isocyanate terminated poly(ethylene glycol) (PEG) as branching unit and phloroglucinol (PG) as aromatic core. The chemical structure of the HB polymer was confirmed using FTIR and NMR. The gel permeation chromatography and solution viscosities indicate polymers of moderately high molecular weights. The thermal behavior and crystalline properties were investigated using differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and polarized optical microscopy. A high fusion enthalpy of 146.6 J g-1 at transition temperature of 56 °C was achieved. Thermal stability was found to be quite high (up to 300 °C), and thermal reliability was retained with no chemical degradation after thermal cycling. The polymer exhibited crystalline to amorphous phase change above the transition temperatures and back, which makes it attractive as a polymeric phase change material for thermal energy storage applications. [ABSTRACT FROM AUTHOR]

A series of semi-interpenetrating polymer networks (IPN) of poly(2-hydroxyethyl methacrylate) (poly(HEMA)) and crosslinked polyethylene glycol (PEG) were prepared by simultaneous IPN polymerisation technique. Tetraethyl orthosilicate (TEOS) was used for crosslinking. The prepared semi-IPNs were characterized by Fourier transform infrared spectroscopy (FTIR), 13 C-nuclear magnetic resonance ( 13 C-NMR), X-ray diffraction (XRD), polarized optical microscopy (POM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), swelling studies and contact angle measurements. The river like pattern of fractured cross section of the SEM micrograph of IPNs indicated no phase separation and also siloxane moiety placement on matrix-air interface. The semi-IPN samples are found to possess crystalline spherulites and the crystallinity reduces as the percentage of poly(HEMA) increases as demonstrated by XRD and POM. Maximum melting enthalpy obtained from DSC thermogram was around 145 J/g. The contact angle studies show that the relative hydrophobicity of the semi-IPNs increases with increase in content of HEMA in the semi-IPNs. These materials show satisfactory latent heat storage capacity and good thermal reliability for application as phase change material (PCM). [ABSTRACT FROM AUTHOR]