SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2017, Vol. 25 ›› Issue (9): 1266-1272.DOI: 10.1016/j.cjche.2016.11.009

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Effect of alkyl chain length on the thermophysical properties of pyridinium carboxylates

Tazien Rashid1, Chong Fai Kait2, Thanabalan Murugesan1   

  1. 1 Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Tronoh 32610, Perak, Malaysia;
    2 Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Tronoh 32610, Perak, Malaysia
  • Received:2016-09-02 Revised:2016-11-19 Online:2017-10-11 Published:2017-09-28

Effect of alkyl chain length on the thermophysical properties of pyridinium carboxylates

Tazien Rashid1, Chong Fai Kait2, Thanabalan Murugesan1   

  1. 1 Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Tronoh 32610, Perak, Malaysia;
    2 Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Tronoh 32610, Perak, Malaysia
  • 通讯作者: Thanabalan Murugesan,E-mail:murugesan@petronas.com.my,murugesan@utp.edu.my,tmgesan_57@yahoo.com

Abstract: In the present study, new series of pyridinium carboxylate protic ionic liquids (PILs) were synthesized by pairing pyridinium cation with carboxylate anion from C1-C3 forming pyridinium formate ([C5H6N+] [HCOO-]), pyridinium acetate ([C5H6N+] [CH3COO-]) and pyridinium propionate ([C5H6N+] [CH3CH2COO-]) respectively. The physical properties namely, density, viscosity, surface tension (298.15-343.15) K, and refractive index (293.15-323.15) K were measured. Thermal properties namely, glass transition temperature, molar heat capacity, and thermal decomposition temperatures were also determined. The thermal expansivity was calculated using the experimental density data. The effect of increasing the alkyl chain length on the thermophysical properties of the pyridinium carboxylate PILs has been evaluated. As expected the physical properties i.e. density, viscosity, surface tension and refractive index of the investigated pyridinium carboxylates decreased with increasing temperature. In general pyridinium carboxylate PILs possessed low viscosity, high thermal stability and excellent hydrogen bonding capability, and these properties lead them to outperform conventional solvents employed for lignin dissolution.

Key words: Protic ionic liquids, Pyridine, Carboxylic acids, Anion, Physicochemical properties

摘要: In the present study, new series of pyridinium carboxylate protic ionic liquids (PILs) were synthesized by pairing pyridinium cation with carboxylate anion from C1-C3 forming pyridinium formate ([C5H6N+] [HCOO-]), pyridinium acetate ([C5H6N+] [CH3COO-]) and pyridinium propionate ([C5H6N+] [CH3CH2COO-]) respectively. The physical properties namely, density, viscosity, surface tension (298.15-343.15) K, and refractive index (293.15-323.15) K were measured. Thermal properties namely, glass transition temperature, molar heat capacity, and thermal decomposition temperatures were also determined. The thermal expansivity was calculated using the experimental density data. The effect of increasing the alkyl chain length on the thermophysical properties of the pyridinium carboxylate PILs has been evaluated. As expected the physical properties i.e. density, viscosity, surface tension and refractive index of the investigated pyridinium carboxylates decreased with increasing temperature. In general pyridinium carboxylate PILs possessed low viscosity, high thermal stability and excellent hydrogen bonding capability, and these properties lead them to outperform conventional solvents employed for lignin dissolution.

关键词: Protic ionic liquids, Pyridine, Carboxylic acids, Anion, Physicochemical properties