Hybrid aluminum colored pigments based on gradient copolymers design
Résumé
A colored polymer/aluminium hybrid pigment was synthesized by nitroxide mediated polymerization initiated from an inorganic surface. This approach requires the preparation of a vinyl dye monomer able to copolymerize with n-butyl acrylate (n-BuA) and styrene (S) from the surface of aluminium flakes. The linearity of the ln([M]0/[M]t) and of the M n as a function of time and conversion constitute the criteria of control/"living" polymerization, i.e. linearity of respectively ln([M]0/[M]t) =f(t) and the Mn = f(conversion) plots. Kinetic measurements reveal an upward deviation from the linearity for n-BuA polymerization for very high conversion. The introduction of S monomer restores the control of the polymerization. Both the length of the grafted chains and the dye/styrene molar ratio influence the color of the hybrid material.