INITIATOR MOLECULE FOR A NON LINEAR ABSORPTION REACTION, PHOTOPOLYMERISABLE COMPOSITION THAT CAN BE ACTIVATED BY BIPHOTONIC ABSORPTION AND ASSOCIATED 3D PRINTING METHOD

摘要

The invention relates to a polymerisation initiator molecule capable of being excited by two photons and generating free radicals that initiate polymerisation, the molecule being characterised in that it comprises two branches grafted on a central phenyl ring, each branch comprising an oligophenylene-ethynylene-yl or oligo 2,5-dihalogen-phenylene-ethynylene-yl type oligomer. The invention also relates to a photopolymerisable composition that can be activated by biphotonic absorption, the composition comprising: - a radically polymerisable resin and - a radical photoinitiator system in a photochemically effective amount, the composition being characterised in that the photoinitiator system comprises at least one initiator molecule as described above. Finally, the invention relates to a method and an associated two-photon 3D printing device, the method comprising a step of transforming a volume of a photopolymerisable composition comprising at least one initiator molecule, transformation being performed by irradiating the composition volume with an irradiation light source emitting an irradiation signal having a wavelength Lirr between 1 and 1.5 times, and preferably between 1.1 and 1.25 times, a cut-off wavelength LCutOff of the initiator molecule. The invention is applicable in two-photon 3D printing with submicron resolution.