Synthesis of novel nanoreinforcements for polymer matrices by ATRP: Triblock poly(rotaxan)s based in polyethyleneglycol end-caped with poly(methyl methacrylate)

Poly(rotaxan)s of poly(ethylene glycol) and α-cyclodextrines (CD) block copolymers end-capped with poly(methyl methacrylate) chains were synthesized by atom transfer radical polymerization. The synthesized copolymers were characterized by 1H NMR, 2D NOESY NMR, X-ray and Thermogravimetric analysis. Assuming a maximum relation of 2 CDs per ethyleneglycol unit, a coverage degree of 18% and 15% was achieved. X-ray analysis showed a characteristic signal around 20θ for all copolymers with an amorphous halo mainly due to inter-crystal poly(ethylene glycol) and poly(methyl methacrylate) chains. Full Molecular Dynamics of 20 ns was used to simulate the crystal structure of these copolymers. A pair correlation function was used to determine the coupling between hydrogen atoms of PEG, PMMA and cyclodextrine obtained by 2D NOESY NMR.