Cholesterol functionalized linear Poly(ε-caprolactone) polymers: Effects of chain length on mesomorphic and dielectric properties


Doganci M., Davarcı D., Uner M., Demir A., Musatat A. B., Akdogan M., ...Daha Fazla

MATERIALS CHEMISTRY AND PHYSICS, cilt.346, 2025 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 346
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.matchemphys.2025.131363
  • Dergi Adı: MATERIALS CHEMISTRY AND PHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: Cholesterol, Liquid crystal, poly(ε-caprolactone), Ring-opening polymerization
  • Kocaeli Üniversitesi Adresli: Evet

Özet

Cholesterol-functionalized linear poly (epsilon-caprolactone) (Chol-PCL) polymers with different chain lengths (n = 10, 20, 30, and 70) were successfully synthesized via a ring-opening polymerization reaction using cholesterol as initiator. Their structures were confirmed by 1H NMR and FT-IR spectroscopy, and their various dielectric properties were extensively investigated in a frequency range from 100 Hz to 1 MHz under different voltage conditions (0-20 V). The results revealed that all the obtained polymers have focal conic fan shape textures of the smectic phase, encouraging the mesomorphism. In particular, Chol-PCL30 showed superior dielectric performance and exhibited the highest capacitance values and optimal dielectric stability over the measured frequency spectrum. The study showed a non-linear relationship between the chain length of PCL and dielectric properties, with the medium chain length (n = 30) providing the most favorable molecular architecture for enhanced charge capability and dielectric response. Complex impedance analysis revealed a pronounced relaxation behavior as a function of chain length, with Chol-PCL30 showing the most pronounced impedance response. These results provide valuable insights into the structure-property relationships in cholesterol-modified PCL systems and their potential applications in dielectric materials. To address the limitations of existing dielectric materials and explore novel polymeric systems with enhanced electrical properties, cholesterol-functionalized linear poly (epsilon-caprolactone) (Chol-PCL) polymers were successfully synthesized with precisely controlled chain lengths (n = 10, 20, 30, and 70) via ring-opening polymerization using cholesterol as an initiator. Structural confirmation was achieved through 1H NMR and FT-IR spectroscopy. A comprehensive investigation into their dielectric properties, including capacitance, conductance, dielectric constant, dissipation factor, electrical modulus, and impedance, was conducted across a broad frequency range (100 Hz-1 MHz) under varying voltage conditions (0-20 V). All synthesized polymers exhibited focal conic fan shape textures characteristic of the smectic phase, indicating their mesomorphic nature. Notably, Chol-PCL30 demonstrated exceptional dielectric performance, exhibiting the highest capacitance values and notable dielectric stability across the measured frequency spectrum. This study revealed a significant non-linear correlation between the PCL chain length and the observed dielectric properties, with the medium chain length (n = 30) providing an optimal molecular architecture for enhanced charge storage capability and dielectric response. Furthermore, complex impedance analysis elucidated a pronounced relaxation behavior that was highly dependent on chain length, with Chol-PCL30 exhibiting the most significant impedance response. These findings offer crucial insights into the intricate structure-property relationships within cholesterol-modified PCL systems, paving the way for their potential application in advanced dielectric materials.