3D Printing of PDMS-Like Polymer Nanocomposites with Enhanced Thermal Conductivity: Boron Nitride Based Photocuring System

Abstract

This study demonstrates the possibility of forming 3D structures with enhanced thermal conductivity (k) by vat printing a silicone–acrylate based nanocomposite. Polydimethylsiloxane (PDSM) represent a common silicone-based polymer used in several applications from electronics to microfluidics. Unfortunately, the k value of the polymer is low, so a composite is required to be formed in order to increase its thermal conductivity. Several types of fillers are available to reach this result. In this study, boron nitride (BN) nanoparticles were used to increase the thermal conductivity of a PDMS-like photocurable matrix. A digital light processing (DLP) system was employed to form complex structures. The viscosity of the formulation was firstly investigated; photorheology and attenuate total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) analyses were done to check the reactivity of the system that resulted as suitable for DLP printing. Mechanical and thermal analyses were performed on printed samples through dynamic mechanical thermal analysis (DMTA) and tensile tests, revealing a positive effect of the BN nanoparticles. Morphological characterization was performed by scanning electron microscopy (SEM). Finally, thermal analysis demonstrated that the thermal conductivity of the material was improved, maintaining the possibility of producing 3D printable formulations.

DLP 4D‐Printing of Remotely, Modularly, and Selectively Controllable Shape Memory Polymer Nanocomposites Embedding Carbon Nanotubes

“…Unlike the neat formulation (F0), all the doped formulations (referred to as FX, where X is the concentration of CNTs in wt.%) show a typical shear‐thinning behavior (Figure S1, Supporting Information), in good accordance with previous reports on resins embedding nanofillers. [ 44,45 ] Further, as becomes clear from the values reported in Table 1, the higher the content of CNTs, the higher the viscosity of the formulations since the interaction between the CNTs limits the mobility of the polymer chains. However, according to the literature, such viscosity values are acceptable for DLP‐Printing.…”

Additives for Ambient 3D Printing with Visible Light

“…Initially, samples without PETMP (tetrathiol) were irradiated under ambient conditions with a red LED centered at 617 nm (full width at half maximum (FWHM) ≈ 19 nm) having an intensity of 2.5 mW cm −2 (matching the DLP 3D printer intensity). For context, commercial UV/violet-light DLP 3D printers that operate at 385-405 nm have reported intensities exceeding 10 mW cm −2 , [38][39][40][41][42][43] which is significantly higher than the present system and represents a future avenue to examine for improved printing speed and resolution. Red LED illumination resulted in an inhibition period of 49.4 ± 0.4 s and an initial rate of polymerization of 7.5 ± 5.3% s −1 (immediately following inhibition) (Figure 3a and Table 1).…”

A Review of Polymer-Based Materials for Fused Filament Fabrication (FFF): Focus on Sustainability and Recycled Materials

“…Other nanoparticles are, for example, silica, which have given greater thermoelasticity, increased handling and performance quality of thermoplastic polymers, or polyhedral oligomeric silsesquioxane (POSS) nanoparticles, that have increased flexural strength (22%), flexural modulus (9%) and toughness (117%), compared to pure PLA [ 85 ]. Furthermore, Pezzana et al 2021 demonstrated the possibility of increasing the thermal conductivity and thermal conductivity of a silicon-acrylate nanocomposite using boron nitride (BN) nanoparticles [ 90 ].…”