A depth-resolved look at the film formation and properties of alkyd-based coatings
Promotion Date: 13 October 2004
The aim of the project was to investigate how the alkyd film is drying. Since the solvent borne paints are used less for environmental reasons, the water borne paints have become more important in the industry. But the drying process presents problems. It is an oxidative drying, so it starts on the surface and is not homogeneous in the depth of the film. So we wanted to know what was happening in the depth of the film. Now there is more research in this field, but not too much was known on the subject when I started.
What was your thesis about?
About paint basically. The aim of the project was to investigate how the alkyd film is drying.
Since the solvent borne paints are used less for environmental reasons, the water borne paints have become more important in the industry. But the drying process presents problems. It is an oxidative drying, so it starts on the surface and is not homogeneous in the depth of the film. So we wanted to know what was happening in the depth of the film. Now there is more research in this field, but not too much was known on the subject when I started.
We monitored the chemical changes in the film during the cross linking processes by using Confocal Raman Microspectroscopy (CRM). The CRM gave information only about the primary cross-linking processes, but we also studied the rest of the cross linking processes because it is important to determine the mechanical properties of the film. We measured the elastic modulus (directly related to the total cross-link density) of the drying coating films using the AFM (atomic force microscopy) nanoindentation technique.
Did you succeed?
Yes, I discovered how the drying process proceeds in the depth of the drying films. I compared the drying process in the solvent borne coatings to the water-borne ones. I also investigated the influence of oil length, rheological modifier and solvent on the drying process. So we were able to make recommendations for improvement of water borne coatings to obtain more homogeneous drying.
Where did you get your sample?
I used a basic coating supplied by Akzo Nobel. I also got the additives from them.
Your promotion has been postponed a bit a because of late results. What were they?
We also wanted to model the influence of several parameters on the drying process to explain our measurement results.
How did the cooperation with industry work?
Akzo Nobel were in the advisory committee of my project and provided their experience as well as the material. We regularly met and I enjoyed it. When I talked to them I got completely different questions than on a conference. Sometimes it was a bit difficult because they would prefer more application and less science, but on the whole we have had an excellent cooperation. And for me personally it was important to see the reasons behind the research. This research had a very practical side and the discussions with Akzo Nobel were very fruitful.
What are you going to do next?
That is still completely unknown. I am looking for a job in the industry in Belgium or Luxembourg, which is a French speaking area. At the moment I am also busy to learn French. I finally managed to cope in Dutch (Beáta is from Hungary), and now French!
Are you not afraid that a lapse in your career may spoil your future job opportunities?
Well, if I can’t find anything in that area, I will try in Antwerp or Brussels. Sooner or later I will find a job somewhere.
How did you come to do your promotion at this university?
After graduation I did want to go abroad for a bit, to do something different. I was not planning to stay here so long, I even had a job in Hungary lined up for me. But for reasons that have to do with my private life I wanted to stay and I found this project.
Since you not actively chose to study here; did you like it?
Very much, I really enjoyed working in the group, which I think it is the most international group at Twente University. Of course at the beginning I missed my friends and family a lot. But now I feel at home here in the Netherlands as well.