Photoinduced sequence-control via one pot living radical polymerization of acrylates

The ability to regulate the activation and deactivation steps via an external stimulus has always been a challenge in polymer chemistry. In an ideal photo-mediated system, whereby high monomer conversion and excellent end group fidelity can be maintained, precise control over the polymer composition and microstructure would be a significant breakthrough. Herein, we report, a versatile, simple and inexpensive method that allows for the synthesis of sequence-controlled multiblock copolymers in a one pot polymerization reaction at ambient temperature. In the absence of a conventional photoredox catalyst and dye-sensitisers, low concentrations of CuBr2 in synergy with Me-6-Tren mediate acrylic block copolymerization under UV irradiation (lambda(max) approximate to 360 nm). Four different acrylate monomers were alternated in various combinations within the polymer composition illustrating the potential of the technique. Narrow disperse undecablock copolymers were obtained (D < 1.2) with quantitative conversion achieved between the iterative monomer additions. The effect of the chain length was investigated allowing for higher molecular weight multiblock copolymers to be obtained. This approach offers a versatile and inexpensive platform for the preparation of high-order multiblock functional materials with additional applications arising from the precise spatiotemporal "on/off" control and resolution when desired.