Chinese Journal of Applied Chemistry ›› 1994, Vol. 0 ›› Issue (2): 89-92.

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Thermotropic Phase Transition of n-Alkylammonium Halides

Wang Wei, Li Laiming, Xi Shiquan   

  1. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022
  • Received:1993-04-28 Revised:1993-09-27 Published:1994-04-10 Online:1994-04-10

Abstract: The thermotropic phase transition of a series of long-chain n-alkylammonium halides (CnH2n+1NH3X,n=8~18,X=Cl, Br)has been studied by differential scanning calorimetry.2 The results show that the main transition temperature of solid-solid structural phase transitions is proportional to the length of hydrocarbon chain. The reverse transitions of the structural transitions exhibit variously hysteresis effect. The melting temperatures decrease linearly with the increase of hydrocarbon chain length. The results suggest that the process of phase transition is relative to the aging and crystallization course of the crystalline samples.

Key words: n-alkylammonium halide, phase transition, differential scanning calorimetry