Epoxidation, hydroxylation, acrylation and urethanation of Linum usitatissimum seed oil and its derivatives

Abstract

Some preliminary studies on epoxidation, hydroxylation, acrylation and urethanation of Linum usitatissimum seed oil (LO) and its derivatives have been carried out. Epoxidation and hydroxylation were performed in situ using H 2O2 and acetic acid to develop epoxidized oil (LOE) and epoxy polyol (EP). EP was modified with synthetic monomers, viz. acrylonitrile (AN) and methylmethacrylate (MMA), in the presence of benzoyl peroxide in an inert environment to develop acrylic grafted epoxy polyols (AEPs). EP and AEPs were further treated with an isocyanate, resulting in the formation of plain and acrylic grafted epoxy polyurethanes (EPU and AEPUs). The mechanism of the reaction as well as the structural aspects of LO, LOE, EP, AEPs, EPU and AEPUs were investigated by 1H-NMR and 13C-NMR spectroscopic techniques, which also confirmed the incorporation of the acrylic monomers - AN and MMA - on the EP backbone Spectral analyses further demonstrated that, depending on its structure (substituent), each acrylic monomer follows a different grafting mechanism. Physico-chemical characterization of AEPs and AEPUs was carried out by standard laboratory methods, and thermal analyses were accomplished by TGA and DSC. Physico-mechanical characterization of AEPUs coatings further showed considerable improvement compared to the pristine (EPU) resin, due to the introduction of stiff acrylic moieties. The aforementioned studies as well as the coating characteristics of AEPU confirmed that AN and MMA have been incorporated in the EP backbone. These systems can be safely employed at up to 210-220°C. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.