POLYMERIZATION OF COMPOSITE MATERIALS IN FREE SPACE ENVIRONMENT

ABSTRACT Light-initiated curing of composite in free space environment appears as one of the most promising processes to turn a foldable, inflatable prepreg into a rigid, load-bearing structure [1]. This paper presents activities aiming at the development of composite materials that complies with the strong requirements associated with in orbit curing, such as stability, flexibility and low outgassing in the uncured state, together with reactivity for rigidization and sufficient mechanical performances in the cured state. The cationic polymerization of epoxy monomer was selected as polymerization process, and dedicated copolymers had to be synthesized to obtain a satisfying material. The obtained results allowed for the successful manufacturing, rigidization and testing of several breadboards

Multi-scale modeling and simulation of thermoplastic automated tape placement: Effects of metallic particles reinforcement on part consolidation

This paper concerns engineered composites integrating metallic particles to enhance thermal and electrical properties. However, these properties are strongly dependent on the forming process itself that determines the particle distribution and orientation. At the same time, the resulting enhanced thermal properties affect the reinforced resin viscosity whose flow is involved in the intimate contact evolution. Thus, a subtle and intricate coupling appears, and the process cannot be defined by ignoring it. In this paper, we analyze the effects of particle concentration and orientation on the process and processability. For this purpose, three main models are combined: (i) a multi-scale surface representation and its evolution, by using an appropriate numerical model; (ii) flow-induced orientation, and (iii) the impact of the orientation state on the homogenized thermal conductivity

Synthesis of β-myrcene/glycidyl methacrylate statistical and amphiphilic diblock copolymers by SG1 nitroxide-mediated controlled radical polymerization

International audienc

Synthesis of β-Myrcene-Based Polymers and Styrene Block and Statistical Copolymers by SG1 Nitroxide-Mediated Controlled Radical Polymerization

International audienc

Divanillin-Based Epoxy Precursors as DGEBA Substitutes for Biobased Epoxy Thermosets

Biobased epoxy monomers from divanillyl alcohol were successfully synthesized and characterized. These monomers, that is, diglycidylether of divanillyl alcohol (DiGEDVA), triglycidylether of divanillyl alcohol (TriGEDVA), and tetraglycidyl of divanillyl alcohol (TetraGEDVA), were then cured with cyclo-aliphatic diamine (IPDA), employed as hardener. The vanillin-based epoxy thermosets so-formed were then characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analyzer (DMA), and tensile tests and were compared to a DGEBA-based reference. These biobased thermosets display phase transition Tα from 140 to 200 °C and have thermal degradation comparable to the DGEBA-based network. This divanillin platform thus appears to be a promising substitute to bisphenol A with the aim at designing high-performance epoxy thermosets for structural composite and adhesive applications