For decades, researchers have been studying 3D printing of submillimeter-scale complex structures. Recent research on 3D printing technology has provided solutions for this purpose, such as Digital Light Processing Technology (DLP). This technology uses ultraviolet (UV) to The liquid polymer resin is converted into a separate solid structure in a precisely controlled manner.
Among all the 3D printing materials, thermosetting photopolymers account for almost half of the 3D printing materials market due to its excellent high-temperature mechanical stability, excellent chemical resistance and good compatibility with high-precision 3D printing systems. However, The covalent bond network formed by UV-induced photopolymerization of these thermosetting photopolymers is often permanent, which will make the resulting 3D printed structures not capable of reprocessing, that is, reshaping, reworking and The ability to recycle. With the explosive growth of the global 3D printing materials, the non-reprocessing of thermosetting photopolymers will cause a lot of material waste and serious environmental impact.
To cope with this environmental challenge, researchers at the Singapore University of Technology and Design (SUTD) have developed a reprocessable thermoset 3D printing material (3DPRTs), which allows 3D printing materials to be reshaped, reconstructed, and recycled.
As one of the project's principals, Kevin, an assistant professor of science and mathematics at the Singapore University of Science and Technology, said: 'We have for the first time developed a reprocessable thermosetting photopolymer that is specifically designed for the use of digital light. Processing technology designed for high-resolution 3D printing. First, high-resolution structures can be reorganized and fixed into arbitrary shapes after printing. This feature can improve printing efficiency. For example, 3D can be generated from flat 2D layers. Folding section. Secondly, the structure is repairable, which means that the damaged part can be reprinted and the structural integrity is ensured to extend the durability of the product. Most importantly, our materials can be recycled for reuse. other aspects. '
Prof. Martin Dunn, another director of the project (now the Dean of School of Engineering and Applied Science at the University of Colorado, Denver) said: 'Overall, the development of 3DPRTs is to solve the environmental problems caused by the rapid consumption of 3D printing materials. Provides a practical solution. 3D printing materials will be widely used in various advanced fields including tissue engineering, software robotics, and nanodevices.
In the 3DPRT resin solution, the UV-sensitivity of the acrylate functional group makes it suitable for UV-curing 3D printing technology, so that 3DPRT can be used to print high-precision complex three-dimensional structure. The hydroxyl and ester functional groups occur at high temperatures The transesterification gives the print structure reprocessability. This reprocessable thermoset 3D printing material developed by the two-step polymerization strategy not only allows the user to reshape the 3D print structure, but also directly performs 3D on the damaged interface. Print to repair damaged parts. In addition, discarded parts can be recycled through transesterification and reused in other areas.