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    Öğe
    Synthesis and Characterization of Maleic Anhydride Modified Poly (Ethylene Glycol) as Polymeric Solid-Solid Phase Change Materials
    (2020) Ertuğral, Tuğba Güngör; Alkan, Cemil
    In this study, a novel type of polymeric solid-solid phase change materials (SSPCMs) and Maleic anhydride (MA) modified poly (ethylene glycol) PEG. MAM-PEG polymers were synthesized from different moleculer weight PEG (Mw: 4000, 6000) .On the other hand two different catalyst system was used; para toluene sulfonic acid (PTSA) and 1,8-Diazabicyclo [5.4.0] undec-7-ene (DBU).The PEG bound to the backbone of the polymers formed crystalline regions responsible from latent heat storage with reversible crystalline to amorphous phase transition as linked unit prevented total melting of the structure. Also MAM-PEG polyester polymers acid and hydroxyl values were determined for number of average molecular weight (Mn) and calculated as 36232 and 49020. Characterization and thermal properties of SSPCMs were performed by using fourier transform infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC) techniques mainly. DSC results showed that solid-solid transitions 36-54 °C temperature range and 163-153 Jg-1 enthalpy. As a result, MAM-PEG polymers were found potential for thermal energy storage (TES) applications.Key words: Thermal energy storage, maleic anhydride, PEG, PCM
  • Küçük Resim
    Öğe
    Synthesis of thermally protective PET–PEG multiblock copolymers as food packaging materials
    (SAGE Publications, 2021) Güngör Ertuğral, Tuğba; Alkan, Cemil
    One of the storage conditions affecting quality of food stuffs due to short shelf life is temperature. Thermal insulation can be achieved by adding phase change materials (PCMs) to packaging materials. PCMs store and release latent heat of phase change during melting and crystallization operations, respectively. Thus, they can provide thermal protection for packaged foods. The aim of this study is to prepare new food packaging materials poly (ethylene terephthalate)–poly (ethylene glycol) (PET–PEG) multiblock copolymers as solid–solid phase change materials (SSPCM) as potential food packaging materials with thermal energy storage (TES) property. Polyesterification was carried out with PEG at different average molecular weights (1000, 4000 and 10,000 g/mol), ethylene glycol (EG) and terephthaloyl chloride (TPC). Synthesized PET–PEG multiblock copolymers were characterized using Fourier transform infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC) methods. The crystal structures of PET–PEG multiblock copolymers were characterized by polarized optical microscopy (POM) and their surface properties were determined by performing contact angle tests. TES capacity of the PET–PEG multiblock copolymers was found in range of 26.1–150.5 J/g. Consequently, this study demonstrates the potential of PET–PEG multiblock copolymers suitable for effective thermal preservation in packaging material applications to maintain the quality of packaged food stuffs.