Photopyroelectric observation of melting in valeric (C5 : 0), linoleic (C18 : 2), linolenic (C18 : 3) and tricosanoic (C23 : 0) free fatty acids

Abstract

Photopyroelectric (PPE) study of some saturated (C5 : 0, and C23 : 0) and unsaturated (C18 : 2 and C18 : 3) free fatty acids was performed in a temperature range that included their melting points. The standard PPE configuration was used consistently during the experiment; the special PPE case requests thermally thick sample and sensor and optically opaque sample. For those fatty acids for which literature data on volume‐specific heat were available (C18 : 2, C18 : 3), the behaviour around the melting point of all static and dynamic thermal parameters (specific heat, thermal conductivity, diffusivity and effusivity) was obtained. Since no data for volume‐specific heat of C5 : 0 and C23 : 0 were found in the literature, only the temperature behaviour of the thermal diffusivity was obtained for these specimens. © 1998 Society of Chemical Industry