| Title |
Recyclable flame retardant phosphonated epoxy based thermosets enabled via a reactive approach |
| ID_Doc |
12373 |
| Authors |
Klingler, WW; Rougier, V; Huang, ZY; Parida, D; Lehner, S; Casutt, A; Rentsch, D; Hedlund, KB; Barandun, GA; Michaud, V; Gaan, S |
| Title |
Recyclable flame retardant phosphonated epoxy based thermosets enabled via a reactive approach |
| Year |
2023 |
| Published |
|
| DOI |
10.1016/j.cej.2023.143051 |
| Abstract |
The development of reusable fire-safe polymers with a prolonged lifetime heralds the switch for a transition towards circular economy. In this framework, we report a novel phosphonated thermoset which is composed of networked phosphonate esters containing both P-C and P-O bonds. Employing a simple one-pot, two-step synthetic methodology, oxirane groups of the epoxy resin were partially reacted with various amounts of reactive bis H-phosphonate monomer, and cured with a cycloaliphatic hardener to obtain multifunctional thermosets with up to 8% phosphorus (P) content. Though 2.5% P was adequate to achieve good flame retardancy, a concentration > 5% P was necessary for accomplishing material reprocessability and recyclability. These phosphonated thermosets exhibited high Tg (94 degrees C - 140 degrees C) and good thermal stability. Fire performance of the thermoset with 2.5% P via cone calorimetry showed effective reduction in the peak heat release rate (pHRR, 75%) and significant inhibition of total smoke production (TSP, 72.5%), which was attributed to the gas and condense phase actions of the phosphonate moieties. This thermoset was explored as a transparent fire-safe coating on wood where an intumescent flame retardant mechanism was observed. The phosphonated thermoset with higher P content (6%) demonstrated excellent damage reparability and thermomechanical reprocessability driven by transesterification induced network rearrangement. This thermoset was used for manufacturing flax fiber reinforced composite, to demonstrate its future application as a polymer matrix for composite materials. |
| Author Keywords |
Flame retardant epoxy thermoset; Phosphonate dynamic bonds; Reparability and reprocessability; Fire-safe coating; Flame retardant mechanism; Flax fiber reinforced composite |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000989090000001 |
| WoS Category |
Engineering, Environmental; Engineering, Chemical |
| Research Area |
Engineering |
| PDF |
https://doi.org/10.1016/j.cej.2023.143051
|