PHOTOPYROELECTRIC OBSERVATION OF MELTING IN VALERIC (C5 0), LINOLEIC (C18/2), LINOLENIC (C18/3) AND TRICOSANOIC (C23/0) FREE FATTY-ACIDS/

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 tem perature range that included their melting points. The standard PPE co nfiguration was used consistently during the experiment; the special P PE case requests thermally thick sample and sensor and optically opaqu e sample. For those fatty acids for which literature data on volume-sp ecific heat were available (C18:2, C18:3), the behaviour around the me lting point of all static and dynamic thermal parameters (specific hea t, thermal conductivity, diffusivity and effusivity) was obtained. Sin ce no data for volume-specific heat of C5:0 and C23:0 were found in th e literature, only the temperature behaviour of the thermal diffusivit y was obtained for these specimens. (C) 1998 Society of Chemical Indus try.