Acrylate‐based photosensitive resin for stereolithographic three‐dimensional printing

Abstract

In this article, we report an acrylate-based three-dimensional (3D) printing stereolithography rapid-prototyping photosensitive resin with a low viscosity, small volumetric shrinkage, high photoreactivity, and excellent strength. The resin was a compound prepared with bisphenol A epoxy acrylate (BAEA) as the main matrix, 1,6-hexanediol diacrylate (HDDA) and tri(propylene glycol) diacrylate (TPGDA) as reactive diluents, pentaerythritol triacrylate (PETA) as the crosslinking agent, and 2-hydroxy-2-methyl propiophenone (1173) and diphenyl(2,4,6-trimethyl benzoyl)phosphine oxide (TPO) as photoinitiators. The photocuring kinetics of the resins with different photoinitiator types and loadings were studied via real-time IR spectroscopy, which provided insights into the optimization of photoinitiator composition and printing parameter settings. The results show that the content change of each component affected the viscosity of the photosensitive resin; this was accompanied by fluctuations in the volume shrinkage and mechanical strength of the cured products. Although an increase in the molar ratio of the reactive diluent remarkably reduced the viscosity of the photosensitive resin and thereby boosted photopolymerization, it also caused an increase in the volume shrinkage and a sacrifice of mechanical strength. Finally, as shown by a comparison of the other samples we studied, the resin composed of 30 mmol HDDA, 50 mmol TPGDA, 10 mmol PETA, 10 mmol BAEA, 2.5 mol % TPO, and 2.5 mol % 1173 achieved the best viscosity of 239.53 mPa s at 25 C, the minimum shrinkage rate of 4.36%, and the maximum tensile strength of 43.19 MPa. The 3D printing curing products had the closest size to the design dimensions of the computer-aided design model; this indicated that the resin seemed to be a most promising candidate for 3D printing applications.

Near‐visible stereolithography of a low shrinkage cationic/free‐radical photopolymer blend and its nanocomposite

“…Indeed, a high viscosity requires longer time to spread uniformly over the build platform and to supply material for each layer. Hence, a low value of viscosity, preferably in the range of 0.15-0.50 PaÁs, 56 is desired to reduce the resin leveling time. Both ENP and ENPS formulations exhibited low values of the viscosity of around 0.11 and 0.24 PaÁs, respectively, with a typical Newtonian behavior in both cases.…”

“…The value exhibited by ENP is even lower than others reported in the literature for other resins used for ST, while ENPS resin showed a comparable viscosity. 56 Physical, Chemical, and Mechanical Characterization of the Printed Materials As already stated, the photopolymerization of ENP resin, which contains both epoxides and acrylates, occurs through both the cationic and free-radical mechanisms. This can lead to the development of an IPN in the final crosslinked materials.…”

Polyethylene glycol modified epoxy acrylateUVcurable3Dprinting materials

“…In the acrylate-based photo-curable system, the bisphenol-A epoxy acrylate is a common matrix. 6,7 The liquid consumables and their UV cured products are not conducive to application due to the lack of flexibility, though with small volume shrinkage, high photo-reactivity, and excellent strength. Therefore, flexible 3D printed product is an important development trend in the future.…”

“…The main components of photo‐curable consumables are resin monomer, prepolymer or oligomer, photoinitiator and reactive diluent. In the acrylate‐based photo‐curable system, the bisphenol‐A epoxy acrylate is a common matrix 6,7 . The liquid consumables and their UV cured products are not conducive to application due to the lack of flexibility, though with small volume shrinkage, high photo‐reactivity, and excellent strength.…”

Photochemical Study of a Three‐Component Photocyclic Initiating System for Free Radical Photopolymerization: Implementing a Model for Digital Light Processing 3D Printing

“…However, many affordable systems available today employ as DLP a commercial video projector based on white light irradiation. Consequently, commonly used photosensitive 3D printing resins are mostly composed of (meth)acrylates monomer/oligomer mix with TPO or BAPO type I photoinitiator (PI) . Recently, more complex systems were proposed, but only few examples of two and three component PIS can be found in literature, and none of them was deeply investigated in terms of 3D printing performance despite the well‐known reactivity of such systems …”