Efficient Copper-Mediated Surface-Initiated Polymerization from Raw Polymer Latex in Water

The copper-mediated radical polymerization of N-acryloylmorpholine initiated from the surface of latex particles in water was studied to form hydrophobic core/hydrophilic shell particles. The latexes were synthesized via classical radical emulsion polymerization and were functionalized at their surface by a comonomer bearing a Br-functional group (the so-called inimer). The latter was introduced to initiate the grafting reaction, in the presence of the Cu(0)/CuBr2/PMDETA (1,1,4,7,7-pentamethyldiethylenetriamine) catalytic system. Conditions in which the grafting step could be performed at room temperature, using high particle concentration in the presence of surfactant and initiator remaining from the emulsion polymerization were identified. The success of the functionalization and grafting steps was evaluated by TOF-SIMS (time-of-flight secondary ion mass spectrometry), by FTIR, and by the final properties of the so-formed core shell particles. It is the first time such grafting conditions have been applied with success from "real latexes".