Modifications induced in photocuring of Bis- GMA/TEGDMA by the addition of graphene nanoplatelets for 3D printable electrically conductive nanocomposites

The incorporation of nanoreinforcement in photocurable polymeric matrices can strongly affect the degree of curing and properties of the final nanocomposites as well as the process parameters for 3D printing. Particularly, the addition of GNPs in contents from 1 up to 10 wt% limits the degree of curing to 60% in Bis-GMA/TEGDMA. The increase up to 10 wt% causes a diminution of ~20% in the mentioned property. Additionally, the maximum thickness that can be cured by UV light abruptly decreases with the GNPs content, being ~400 μm when using 1 wt% and below 20 μm for nanocomposites filled with 10 wt%. Above the percolation threshold, the electrical conductivity of the photocured monolayers is dependent on the curing time, making possible the use of this materials as self-sensor of the degree of curing in additive manufacturing technologies.