Sains Malaysiana 40(1)(2011): 49–54

Polymer Gel Electrolytes Based on 49% Methyl-Grafted Natural Rubber

(Elektrolit Gel Polimer Berasaskan 49% Metil Cangkukan Getah Asli)

A.S. Kamisan¹, T.I.T. Kudin¹, A.M.M. Ali¹ & M.Z.A. Yahya^1,2,*

¹Ionic Materials & Devices (iMADE) Research Laboratory

Faculty of Applied Sciences, Universiti Teknologi MARA

40450 Shah Alam, Selangor D.E., Malaysia

²Institute of Sciences, Universiti Teknologi MARA

40450 Shah Alam, Selangor D.E., Malaysia

Received: 7 December 2009 / Accepted: 16 July 2010

ABSTRACT

Polymer gel electrolytes (PGEs) based on 49% methyl-grafted natural rubber (MG49) were first prepared by dissolving ammonium triflate (NH4CF₃SO₃) in propylene carbonate (PC) by various molar concentrations of NH4CF₃SO₃ to obtain liquid electrolytes and were characterized by AC electrical impedance spectroscopy (EIS) measurements to study their conducting behaviour. The liquid electrolyte with optimum conductivity (0.7M) was then gelled with MG49 and their conductivity was also studied. The highest conductivity of liquid electrolyte was 3.6×10^-3 Scm^-1 and 2.9×10^-2 Scm^-1 for PGEs. The molecular interactions between components of NH4CF₃SO₃, PC, and MG49 have been observed by ATR-FTIR spectroscopy study. The downshifting of C=O stretching frequency of PC from 1785 cm-1 to 1780 cm^-1 and NH⁴⁺ band from 1634 cm^-1 to 1626 cm^-1 that has been obtained by spectroscopic data in addition of NH4CF3SO3 confirmed the complexation occurrence. Interaction between NH4CF₃SO₃ and MG49 has also been investigated. This study is focused on the interactions between components in the PGE system and relates them with their conducting behavior.

Keywords: Ammonium triflate; complexation; conductivity; MG49; polymer gel electrolyte

ABSTRAK

Elektrolit gel polimer berasaskan 49% metil cangkukan getah asli (MG49) disediakan dengan melarutkan ammonium triflat (NH4CF₃SO₃) dalam propilena karbonat (PC) dengan pelbagai kepekatan molar bagi menghasilkan elektrolit cecair dan sifat kekonduksiannya diuji menggunakan alat spektroskopi impedans elektrik arus ulang-alik. Elektrolit cecair dengan kekonduksian optimum (0.7M) kemudian digel bersama MG49 dan ciri kekonduksiannya juga dikaji. Nilai kekonduksian paling tinggi bagi elektrolit cecair ialah 3.6×10^-3 Scm^-1 dan 2.9×10^-2 Scm^-1 bagi elektrolit gel polimer. Interaksi molekul antara komponen NH4CF₃SO₃, PC, dan MG49 diperhatikan melalui kajian spektroskopi ATR-FTIR. Anjakan frekuensi regangan C=O PC daripada 1785 cm-1 ke 1780 cm-1 dan jalur NH⁴⁺ daripada 1634 cm^-1 ke 1626 cm^-1 dengan penambahan NH4CF₃SO₃ yang diperoleh daripada data spektroskopik mengesahkan berlakunya kompleks antara PC dan NH4CF₃SO₃. Interaksi antara NH4CF₃SO₃ dan MG49 juga turut dikaji. Kajian ini memfokus pada interaksi antara komponen-komponen dalam sistem elektrolit gel polimer dan mengaitkan dengan sifat-sifat kekonduksiannya.

Kata kunci: Ammonium triflat; elektrolit gel polimer; kekonduksian; kompleks; MG49

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*Corresponding author; email: mzay@salam.uitm.edu.my