3D printing of biodegradable and self-monitoring SWCNT-loaded biobased resin

In this paper a acrylated epoxidized soybean oil (AESO) based photo-curable resin loaded with 0.25% by weight of single walled carbon nanotubes (SWCNT) was produced to manufacture biobased, self-monitoring and biodegradable materials via 3D printing digital light processing (DLP). The CNT addition plays a role in providing self-monitoring properties, however they affect the 3D printing process as they absorb UV radiation which has to be compensated by increasing the exposure time. The produced 3D printed samples show good dimensional/geometrical definition, interesting mechanical properties (elastic modulus of 25 MPa, tensile strength of 2.6 MPa and Shore D hardness in the range 50-60) and very good self-monitoring performance, as the materials offer satisfactory sensitivity (Gauge Factor GF = 3, higher than commercial strain gauge sensors). Accelerated degradation tests in NaOH solutions at different concentration showed that 3D printed samples suffer hydrolytic degradation confirming the biodegradability feature.