Study of the drying of linseed oils with different fatty acid patterns using RTIR-spectroscopy and chemiluminescence (CL)
2005 (English)In: Industrial crops and products (Print), ISSN 0926-6690, Vol. 21, no 2, 263-272 p.Article in journal (Refereed) Published
The oxidative drying of two different linseed oil coatings with either high content of linoleic or linolenic fatty acids have been studied. The curing performance has been followed by a combination of two different analytical techniques, real-time infrared (RTIR) spectroscopy and chemiluminescence (CL) at different temperatures. The effect of a metal drier on the drying process has also been evaluated. The purpose was to reveal how structural variations can improve the drying performance and film properties for oxidative drying linseed oil coatings. The reaction rate is increased for both oils with increased temperature as expected. The oil rich in linolenic acid reacts more rapid and exhibits shorter induction times compared to the oil rich in linoleic acid. The addition of a metal drier further accelerates the drying but in a different manner for the different oils. The oil high in linolenic acid oxidizes so rapidly that a skin layer, acting as a diffusion barrier to atmospheric oxygen, is formed. The through drying rate is then strongly reduced, leaving high levels of residual unsaturation in the film. As a consequence, this will generate poor ageing properties. The oil richness in linoleic acid shows, much better through drying properties even when the reaction is accelerated by both the use of a metal drier and high temperatures. The consequence is that the linseed oil high in linoleic acid can be cured rapidly with good through drying and low levels of residual unsaturations. The combination of the two analytical techniques gives complementary information of the drying mechanisms of the linseed oils. The techniques are shown to be very useful when following oxidative drying of thin films.
Place, publisher, year, edition, pages
2005. Vol. 21, no 2, 263-272 p.
linseed oil, auto-oxidative drying, real-time infrared spectroscopy, chemiluminescence, linolenic acid, mechanisms
IdentifiersURN: urn:nbn:se:kth:diva-14597DOI: 10.1016/j.indcrop.2004.04.002ISI: 000227603600014ScopusID: 2-s2.0-13944278452OAI: oai:DiVA.org:kth-14597DiVA: diva2:332638
QC 201005252010-08-052010-08-05Bibliographically approved