Monomer

Organic chemistry

Polymer chemistry

Radical polymerization

Chain transfer

Engineering

Kinetic chain length

Chemistry

Acrylate

Polymerization

Chemical engineering

Polymer

Bulk polymerization

Nature Chemistry

In polymer chemistry, mechanical energy degrades polymeric chains. In contrast, in nature, mechanical energy is often used to create new polymers. This mechanically stimulated growth is a key component of the robustness of biological materials. A synthetic system in which mechanical force initiates polymerization will provide similar robustness in polymeric materials. Here we show a polymerization of acrylate monomers initiated and controlled by mechanical energy provided by ultrasonic agitation. The activator for an atom-transfer radical polymerization is generated using piezochemical reduction of a Cu(II) precursor complex, which thus converts a mechanical activation of piezoelectric particles to the synthesis of a new material. This polymerization reaction has some characteristics of controlled radical polymerization, such as narrow molecular-weight distribution and linear dependence of the polymeric chain length on the time of mechanical activation. This new method of controlled radical polymerization complements the existing methods to synthesize commercially useful well-defined polymers. Mechanochemically controlled polymerization is rare in polymer chemistry. Now, it has been shown that mechanical force can initiate and control the polymerization of an acrylate monomer. Piezochemical reduction of a copper(II) precursor using mechanical agitation of piezoelectric nanoparticles generates the polymerization activator required for controlled radical polymerization.

Mechanically controlled radical polymerization initiated by ultrasound