A New Versatile Radical Addition on α , ω ‐Dimethacrylate Poly(ethylene oxide)
Résumé
The synthesis of α ,ω ‐di(2‐methyl‐6‐pyrenyl‐2‐succinimidylhexanoic ester)poly(ethylene oxide) (Py(S)‐EOn ‐(S)Py) was obtained by a new radical reaction between 4‐pyrenylbutanoate N ‐hydroxysuccinimidyl ester and α ,ω ‐dimethacrylate poly(ethylene oxide). The reason for the choice of such bulky groups is a possible application of this reaction to the synthesis of polyrotaxane from polypseudorotaxane. Two reaction media were examined, heterogeneous in water at room temperature using persulfate as initiator, or homogeneous in DMSO at 60 °C using AIBN as initiator. Structural characterization of the functionalization products was carried out by SEC, MALDI TOF, and NMR spectroscopies. It was shown that two types of α ,ω ‐dipyrenyl PEO could be obtained, one corresponding to the expected product (Py(S)‐EOn ‐(S)Py), the other corresponding to the same structure but without the succinimidyl substituent (Py(H)‐EOn ‐(H)Py). It was also shown that in the soluble system macrocycles could be formed and this last aspect has been assigned to intramolecular interactions existing between the pyrenyl groups. An interesting aspect of this synthesis is the possibility to find conditions giving high yields without crosslinking and fairly reduced amount of coupling.