2026-01-13 スイス連邦材料試験研究所(EMPA)
The transparent resin can be used alone and as a composite material with carbon fibers. Image: Empa
＜関連情報＞
- https://www.empa.ch/web/s604/flamm-hemmendes-epoxidharz-nachhaltiger-machen
- https://www.sciencedirect.com/science/article/pii/S1385894725066173
反応性ポリホスホネートによる持続可能な耐火性エポキシ複合材料 Sustainable fire-safe epoxy composites enabled by reactive polyphosphonates
Arvindh Sekar, Hermance Muller, Cédric Hervieu, Sithiprumnea Dul, Milijana Jovic, Dambarudhar Parida, Sandro Lehner, Patrick Rupper, Edith Perret, Sabyasachi Gaan
Chemical Engineering Journal Available online: 27 July 2025
DOI:https://doi.org/10.1016/j.cej.2025.165779
Highlights
- Vitrimeric epoxy thermosets (ETs) were made using polyphosphonates, enabling recyclability and flame retardance.
- ETs reach UL-94 V-0 at 2.5 wt% P and retain high Tg (>140 °C) and modulus (~3.8 GPa).
- ETs allowup to 10 hot-press cycles with minimal loss in flame-retardant and mechanical performance.
- Alcoholysis enables recovery of epoxy matrix and carbon fibers, for closed-loop composite reuse.
- Unlike traditional thermosets, these networks retain function despite internal reconfiguration.
Abstract
The closed-loop recycling of thermoset plastics remains a critical challenge, especially as demand grows for materials that combine high performance with fire safety. This study presents a new class of inherently flame-retardant epoxy thermosets (ETs) incorporating reactive polyphosphonates as co-monomers. The resulting amine-cured ETs achieve UL94 V-0 ratings at just 2.5 wt% phosphorus loading, alongside excellent mechanical and thermal performance (Tg = 140–175 °C, tensile strength = 100–110 MPa, modulus = 3.8 GPa). Remarkably, these ETs enable repeated thermomechanical reprocessing, up to ten cycles, without significant loss of performance. When cured with acid anhydrides, the polyphosphonate-based ETs undergo complete chemical depolymerization via alcoholysis, in stark contrast to conventional amine-cured systems. This recyclability extends to carbon-fiber reinforced composites (CFRCs), allowing both carbon fiber recovery and matrix regeneration. These results highlight a promising route toward sustainable, high-performance thermosets with intrinsic flame retardancy and closed-loop recyclability.
