Systematic research of physicochemical properties of functional photopolymers for additive manufacturing

Resumen

This PhD thesis researches the physicochemical properties of photopolymers employed in laser stereolithography focusing on the effects of mass and surface functionalizations. The mass functionalization is based on the incorporation of copper nanowires, copper nanowires with copper nanoparticles, copper-nickel nanowires, and graphene oxide at different concentrations, and times different post-cured. The nanofillers used lead to innovative photopolymeric resins, whose additive manufacturing is validated for the first time in this research. Once the substrates are manufactured, the modified resins perform similarly to the samples manufactured pure resin, without nanofillers. In addition, the surface functionalization was performed through the deposition of titanium and diamond-like-carbon by the direct current sputtering magnetron technique. Accordingly, in this research experimental details, the methods, and materials used in the design and manufacture of the selected specimens are described. Likewise, it presents the results and discussions obtained from the analysis of the physicochemical properties of the substrates manufactured by laser stereolithography, using pure photosensitive resin and with dispersed nanofillers as reinforcing agents (copper nanowires, copper nanowires with copper nanoparticles, copper-nickel nanowires, and graphene oxide); as well as the quality of coatings deposited (titanium and diamond-like-carbon). The morphological, mechanical, thermal and chemical characterization was performed by means of scanning electron microscopy, energy dispersive spectroscopy, computed tomography scan, tensile testing, instrumented indentation, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, Raman spectroscopy, Fourier-transformed infrared spectroscopy, and X-ray diffraction. As a result of the characterization studies, this research evidences the effects of dispersion and use of fillers different type, as a reinforcement material in a commercially available photopolymer resin. Likewise, is validate the quality and the aspect of coatings deposited on the surface of the specimens, which presents a homogeneous color and without delamination. The morphological, mechanical, thermal and chemical results of the manufactured specimens, layer by layer approach using a low-cost laser stereolithography system working with a layer thickness of 100 μm, were examined under well-controlled experimental conditions and technological processes. Consequently, the viability and potentials of mass and surface functionalized photopolymers and devices processable through laser stereolithography is presented and discussed, considering the main current challenges.