4D-Printed Resins and Nanocomposites Thermally Stimulated by Conventional Heating and IR Radiation

The shape memory (SM) capabilities of nanocomposites based on two photocurable acrylated/methacrylated resins, doped with carbon nanotubes (CNTs), and manufactured by digital light processing 3D printing were investigated. The mechanical properties and glass transition temperature (T-g) can be tailored in a broad range by varying the weight ratio of the two resins (T-g ranging from 15 to 190 degrees C; Young's modulus from 1.5 to 2500 MPa). Shape fixity (S-F) and recovery (S-R) ratios are strongly influenced by the temperature being significantly higher at temperatures close to the T-g. The results confirm that the S-F strongly depends on the stiffness of chain segments between cross-linking points, whereas the S-R mainly depends on the cross-link density of the network. CNT addition barely affects the S-F and S-R in the conventional oven, whereas the recovery speed using IR heating is significantly increased for the doped nanocomposites due to their higher IR absorbance.

Automated summary

The shape memory capabilities of nanocomposites based on two photocurable acrylated/methacrylated resins, doped with carbon nanotubes, and manufactured by digital light processing 3D printing were investigated. The study found that mechanical properties and glass transition temperature can be tailored by varying the weight ratio of the two resins in a broad range. Shape fixity and recovery ratios are strongly influenced by temperature and different structural parameters.