3D/4D Printing of Polyurethanes by Vat Photopolymerization

Abstract

Vat photopolymerization relies on the light‐induced polymerization of liquid photopolymer to produce the targeted structure. Among all the polymers prepared by vat photopolymerization, due to their numerous properties polyurethanes have recently gained great attention in the industrial and academic fields. In this review article, recent progress in printing techniques, resin compositions, and applications related to 3D/4D printing by vat photopolymerization of polyurethanes are highlighted.

Light‐Mediated Polymerization Catalyzed by Carbon Nanomaterials

“…Light-mediated polymerization has received increasing interest in polymer synthesis for use in diverse fields. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Examples include, but not limited to lithography, [4,9,[20][21][22] printing based on 2D, [4,15,23,24] 3D [4,6,8, or 4D [27][28][29]53,54] patterning, holographic recording, [16,55,56] fabrication of prosthesis, [57] dental composites, [38,46,58] anti-counterfeiting materials, [59] inks, [4,60,61] surface modification of solidified coatings [4,13,…”

Naphthalene–stilbenes as effective visible-light sensitizers to study the effect of diluent and nanofillers on in situ photopolymerization and 3D-VAT printing process

“…There are many types of reactive and non-reactive diluents, and studying their effects on photopolymerization and 3D printing is an integral part of the research into additive technologies. 49–52…”

“…There are many types of reactive and non-reactive diluents, and studying their effects on photopolymerization and 3D printing is an integral part of the research into additive technologies. [49][50][51][52] Another currently significant field is nanocomposites with various functional nano-sized fillers, which provide variable, tuneable, and often improved material properties. 53 Nanoadditives can increase the mechanical tensile or compressive strength of materials, 54,55 increase their thermal 56,57 or electrical conductivity (e.g., CNTs 58,59 and PEDOT 60 ), and, for example, give them biocompatible or antibacterial properties.…”

Waterborne Polyurethane Latexes for Vat Photopolymerization

“…Alternatively, direct ink write (DIW) and VP enable geometrically complex PU thermosets with acrylate/methacrylate-functionalized oligomers/polymers . Addition of base or photobase generators allowed polymerization of isocyanate and alcohol precursors, facilitating dual cure systems. − Most recently, Carbon3D has offered a range of elastomeric materials, such as EPU 40, as photocurable PU-based elastomers relying on acrylates to provide structural integrity while printing and postcuring to enhance mechanical performance. , However, VP of these precursors requires oligomers to ensure low viscosities. Sardon et al suggest the possibility of waterborne polyurethanes (WPUs) as viable VP precursors to enable the processing of high-molecular-weight polymers …”