Bio-based multifunctional fatty acid methyl esters as reactive diluents in coil coatings

Abstract

The increased environmental awareness has driven academia and industry to utilize environmentally benign sources. An industrially available process that is effective in the coatings industry is the coil-coating process where sheet steel can be pre-coated. During this process volatile organic compounds (VOCs) are generated and incinerated for energy recovery. One way to minimize VOCs is to use a reactive diluent i.e. a molecule that acts both as a solvent as well as chemically react into the final coating upon curing. Fatty acid methyl esters obtained from renewable resources such as vegetable oils are suitable candidates as reactive diluents. In this paper epoxidized fatty acid methyl esters (e-FAMEs) obtained from epoxidized linseed oil where compared with fatty acid methyl esters (FAMEs) obtained from rapeseed oil as reactive diluents in coil-coating formulations. Coil-coating formulations were followed by real-time Fourier transform infrared spectroscopy (RT-FTIR) in order to evaluate the e-FAMEs or the FAMEs reactivity in the coating system. In addition, coil-coating formulation containing e-FAME or FAME where cured in a pilot scale simulated coil-coating process. Moreover, thermal properties of the final coatings were evaluated by differential scanning calorimetry (DSC).