Synthesis of bio-plasticizer from epoxidized vegetable oils
Résumé
Introduction
The use of renewable resources in the elaboration of various industrial materials and chemical has been recently revitalized because of environmental concerns. Nowadays, vegetable oils constitute one of the most important classes of renewable resources. To substitute the phthalate derivatives that are used at present as plasticizers for PVC, modified vegetables oils were prepared as a new bio plasticizer [1]. Efficient oxirane ring opening of fatty epoxides was performed to synthesis various diesters. Modified oils were characterized. In this paper, we wish to present catalyzed ring opening reaction and effects of esters groups on the PVC plasticisation.
Results and discussion
We prepared a range of products via successive ring oxirane opening reaction with a series of acids then esterification of the resulting alcohol with anhydride. The reaction was performed in solvent free conditions and the influence of the catalysts (homogeneous or heterogeneous) in these reactions was evaluated. With this approach symmetric and dissymmetric esters were prepared [2-3].
Among the evaluated catalysts, NBu4Cl, TiO2 and Nb2O5 exhibited significant activities for both reactions. Optimisations of the reaction conditions were performed in order to achieve complete conversion. The reaction has been perfomed on G scale. The products were characterized by NMR, GC and TGA and their properties as a bioplasticizer for PVC were evaluated.
Fig. 1: Viscoelastic profile of plastisol with modified oils
(AcMeSBO : acetylated methyl soyate, BzMeSBO : methyl soyate with benzoate,
Ac/CyclohMeSBO : methyl soyate with acetate and cyclohexanoate)
Plastisols were prepared by mixing PVC and the fatty ester derivatives (PVC/plasticizers: 2/1 in mass?). The angular frequency used is 6.3 rd/s. The storage modulus G’ was recorded as function of temperature (fig. 1). The temperatures of gelation were almost the same as the standard plasticizer (DINP). Some modified vegetable oils may be good candidates to substitute the phthalate derivative usually added as plasticizer. The influence of the chemical modifications on the properties will be described.
Conclusion
This two-step ring opening approach allowed to prepare a range of potential bioplasticizers for PVC starting from vegetable oils. is an interesting method to add new functions on fatty acid esters and it can be applied to the synthesis of PVC bio plasticizers.
References
[1] R. Stringer, I. Labunska, D. Santillo, J. Siddorn, A. Stephenson, Environ Sci Pollut Res 2000 7,1, 27-36.
[2] G. Fogassy, C. Pinel, G. Gelbard, Cat. Commun. 2009 10, 557-560
[3]G. Fogassy, P. Ke, F. Figueras, P. Cassagnau, S. Rouzeau, V. Courault, G. Gelbard, C. Pinel, Appl. Catal. A, 2011 393, 1–8