Study of Photo-Polymerization Induced Self-Assembly of Block Copolymers for 3D Printing – PIMPS3D

PIMPS-3D proposes a novel process for 3D printing, combining photo-polymerization and block copolymer self-assembly, as part of a collaboration between the academic institutes IPREM et IS2M and Arkema specialty chemicals. Our line of approach is two-pronged: (i) Fundamental/experimental research aiming at a better understanding of the photo-polymerization and the induced self-assembly mechanisms leading to out of thermodynamic equilibrium morphologies and of the structures-final properties relations. (ii) Strategic industrial interest for the development of a new and innovative sector, specifically targeting 3D printing.
PIMPS-3D aims to develop nano-structured polymer materials by means of block copolymers in order to control the processing and application properties of the printed parts (rheology, shock resistance, optical properties, etc.) while paying attention to recyclability. We will do this by taking advantage of the PIMPS process (Polymerization Induced Micro-Phase Separation), an approach in which a macro-initiator is dissolved in a monomer of different chemical nature, which leads, by bulk polymerization, to segregated block copolymers and thus nano-structured materials when total monomer conversion is achieved. The advantage of this synthesis strategy, contrary to the use of pre-synthesized block copolymers, is a better matching with the specific requirements of 3D printing.
So far, and independent of 3D printing, this strategy has been mainly applied through thermo-activated processes, and hardly at all through photo-activated ones. However, photo-polymerization is undergoing significant development with numerous industrial applications. Here, we will explore implementation of the photo-activated PIMPS processes in 3D printing, by seeking to overcome several challenges, such as the control of the initiation and kinetics of polymerization as well as the control of the induced self-assembly.
Since photo-polymerization processes are fast, it is essential to develop appropriate in-situ and time-resolved characterization methods to monitor polymerization and morphology, from the initial solution to the final material, in order to highlight the synthesis /reactivity /structuring relationships. Complementary structure- properties relations on the final materials obtained by classical photo-polymerization and 3D printing will be obtained, specifically a study of the role of the macromolecular architectures and processing methods. In addition, the selected cross-linker free systems, based on nano-structuration will be specifically designed to achieve improved mechanical properties and recyclability of printed parts. In parallel, 3D printing methods will be designed and developed with the CANOE instrument pool, to improve efficiency in monomer & energy consumption and safety. In a nutshell, the aim is to generate recyclable and structured materials in a controlled way from the nanometer to the millimeter length scales.