Fast Dynamic Siloxane Exchange Mechanism for Reshapable Vitrimer Composites.
J Am Chem Soc
; 144(27): 12280-12289, 2022 07 13.
Article
in En
| MEDLINE
| ID: mdl-35758403
ABSTRACT
To develop siloxane-containing vitrimers with fast dynamic characteristics, different mechanistic pathways have been investigated using a range of catalysts. In particular, one siloxane exchange pathway has been found to show a fast dynamic behavior in a useful temperature range (180-220 °C) for its application in vitrimers. The mechanism is found to involve 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) as an organic catalyst in the presence of hydroxyl groups. Using this new mechanistic approach, vitrimers with ultrafast stress-relaxation characteristics (relaxation times below 10 s) have been prepared with a readily available epoxy resin and siloxane-amine hardener. Subsequently, the low viscosity siloxane-containing vitrimer resin enabled the preparation of glass fiber-reinforced vitrimer composites using an industrially relevant vacuum-assisted resin infusion technique. The resulting composite was successfully thermoformed into a new shape, which makes it possible to envision a second life for such highly engineered materials.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Siloxanes
Language:
En
Journal:
J Am Chem Soc
Year:
2022
Type:
Article
Affiliation country:
Belgium