Heats of Dissolution of n-Fatty Acids in Ethanol

概要

論文の詳細を見る
The heats of dissolution (ΔH_d) of B polymorph of 1-tetradecanoic acid (C14), 1-pentadecanoic acid (C15), 1-hexadecanoic acid (C16), 1-heptadecanoic acid (C17) and 1-octadecanoic acid (C18) were measured at 310.15 K in ethanol using a calorimetric technique. In ethanol, no concentration dependence of ΔH_d was found within the concentration range of at least 1×10^<-3>-2×10^<-2> moldm^<-3>. At a concentration of 1×10^<-2> moldm^<-3>, the values of ΔH_d were 60.6,66.0,69.4,75.6 and 79.1 kJ mol <-1> for C14,C15,C16,C17 and C18,respectively. ΔH_d increased linearly by increasing the number of carbon atoms (n) in the fatty acid (FA), so that the (CH_2)-increment was obtained as 4.40±0.10 kJ mol^<-1>.ΔH_d was compared with the heats of fusion (ΔH_f). ΔH_d was higher than ΔH_f, and the difference between ΔH_d and ΔH_f for odd-numbered FA was larger than that for even-numbered FA. This is related to the phenomena that the plots of ΔH_f vs. n indicate a zig-zag pattern and those of ΔH_d vs. n indicate a single line pattern.
公益社団法人日本薬学会の論文
1990-09-25