Deep eutectic solvent (DES) is an alternative solvent which has the basic characteristics as conventional ionic liquid. The uniqueness lies on its easy synthesis, less toxic and low-cost production. Three glycol-based DES (ethylene glycol, tetraethylene glycol and poly (ethylene glycol)) with tetrabutylammonium chloride (TBAC) as the hydrogen bond acceptor were successfully prepared. Unusually, all DES was achieved their eutectic mixing as low as 50 °C within 60 min. Thermal analysis study revealed that the most stable DES was the one with higher ethoxy chains. Structure elucidation study via Fourier transformation infrared (FTIR) spectroscopy confirmed the formation of eutectic mixture based on the intermolecular interaction from decreasing hydroxy group stretching frequency. Modifying ethoxy repeating unit in hydrogen bond donor could tailor the design of DES for numerous applications. © 2019 Elsevier B.V.