Abstract: Photocurable colloid binders are provided that overcome deficiencies associated with 3D printing of high molecular weight polymers via VAT photopolymerization. Methods of additive manufacturing are also provided using the binders. The approaches described herein effectively decouple the viscosity-molecular weight relationship by synthesizing and processing photo-reactive aqueous colloids that are sequestered within a photocrosslinkable scaffold. Sequestering polymers within discrete internal phases prevents inter-particle entanglement of the polymer chains, thus ensuring low viscosity. VP of polymer colloids results in a solid green body embedded with high molecular weight polymer particles. A post-processing heated drying step allows the polymers to coalesce and further entangle, forming a semi-interpenetrating network with mechanical performance of the high molecular weight material. The resins can further include inorganic particles such as silica and other ceramics, metal particles, and the like.

Abstract: Photocurable colloid binders are provided that overcome deficiencies associated with 3D printing of high molecular weight polymers via VAT photopolymerization. Methods of additive manufacturing are also provided using the binders. The approaches described herein effectively decouple the viscosity-molecular weight relationship by synthesizing and processing photo-reactive aqueous colloids that are sequestered within a photocrosslinkable scaffold. Sequestering polymers within discrete internal phases prevents inter-particle entanglement of the polymer chains, thus ensuring low viscosity. VP of polymer colloids results in a solid green body embedded with high molecular weight polymer particles. A post-processing heated drying step allows the polymers to coalesce and further entangle, forming a semi-interpenetrating network with mechanical performance of the high molecular weight material. The resins can further include inorganic particles such as silica and other ceramics, metal particles, and the like.

Abstract: In various aspects, top-down stereolithography apparatus and methods of use thereof are provided herein that allow for additive manufacturing of an article from a high-viscosity resin. The apparatus and methods can print resins having viscosities higher than conventional systems, e.g. viscosities up to about 100 Pa·s at the elevated temperature. The resin may have a room temperature viscosity of about 100 Pa·s, about 250 Pa·s, about 1000 Pa·s, or more. In some aspects, the resin is a solid at room temperature. The apparatus and methods do not rely upon solvents or other viscosity modifiers being added to the resin, and are capable of top-down additive manufacturing approaches which provide reduced stress on the printed article.

Abstract: In various aspects, a polymer resin is provided for vat photopolymerization. The resin can include a polyamic acid salt formed from the addition of a photocrosslinkable amine to a polyamic acid. The resin can include a photoinitiator suitable for initiating crosslinking of the photocrosslinkable amine when exposed to a light source of a suitable wavelength and intensity. The polyamic acid can be formed, for instance, by the addition of a diamine to a suitable dianhydride. Methods of additive manufacturing using the resins are also provided.

Abstract: Polymer resins for the vat photopolymerization of thermoplastics are provided, in particular for the vat photopolymerization of thermoplastics with exception thermal stability and mechanical properties. In some aspects, the polymer resins are prepared by ring opening of an aromatic dianhydride with an alcohol containing an acrylate or methacrylate to produce a photocrosslinkable diacid monomer; conversion of the photocrosslinkable diacid monomer to a photocrosslinkable diacyl chloride; and polymerization of the photocrosslinkable diacyl chloride with an aromatic diamine to produce a photocrosslinkable precursor polymer. Upon crosslinking and drying, a thermal imidization can yield aromatic polyimide polymers with high yield and with micron-scale structural resolution.