Improvement of the Thermal and Optical Performances of Protective Polydimethylsiloxane Space Coatings with Cellulose Nanocrystal Additives.
This work investigates the possibility of using cellulose nanocrystals (CNCs) as biobased nanoadditives in protective polydimethylsiloxane (PDMS) space coatings, to improve the thermal and optical performances of the material. CNCs produced from wood pulp were functionalized in different conditions with the objective to improve their dispersibility in the PDMS matrix, increase their thermal stability and provide photoactive functions. Polysiloxane, cinnamate, chloroacetate and trifluoroacetate moieties were accordingly anchored at the CNCs surface by silylation, using two different approaches, or acylation with different functional vinyl esters. The modified CNCs were thoroughly characterized by FT-IR spectroscopy, solid-state NMR spectroscopy and thermogravimetric analysis, before being incorporated into a PDMS space coating formulation in low concentration (0.5 to 4 wt %). The cross-linked PDMS films were subsequently investigated with regards to their mechanical behavior, thermal stability and optical properties after photoaging. Results revealed that the CNC additives could significantly improve the thermal stability of the PDMS coating, up to 140 °C, depending on the treatment and CNC concentration, without affecting the mechanical properties and transparency of the material. In addition, the PDMS films loaded with as low as 1 wt % halogenated nanoparticles, exhibited an improved UV-stability after irradiation in geostationary conditions.
Université Bordeaux , Bordeaux INP, LCPO, UMR 5629, F-33600 Pessac, France.|CNRS, LCPO, UMR 5629, F-33600 Pessac, France.|CNES-French Aerospace Agency , 18 avenue Edouard Belin, F-31401 Toulouse cedex 9, France.
Mikael
M
Planes
Université Bordeaux , Bordeaux INP, LCPO, UMR 5629, F-33600 Pessac, France.|CNRS, LCPO, UMR 5629, F-33600 Pessac, France.
Jérémie
J
Brand
ONERA-The French Aerospace LAB , F-31055 Toulouse France.
Simon
S
Lewandowski
CNES-French Aerospace Agency , 18 avenue Edouard Belin, F-31401 Toulouse cedex 9, France.
Stéphanie
S
Remaury
MAP-ZI , 2 rue Clément Ader, 09100 Pamiers, France.
Stéphane
S
Solé
CNRS, LCPO, UMR 5629, F-33600 Pessac, France.
Cédric
C
Le Coz
Université Bordeaux , Bordeaux INP, LCPO, UMR 5629, F-33600 Pessac, France.|CNRS, LCPO, UMR 5629, F-33600 Pessac, France.
Stéphane
S
Carlotti
Université Bordeaux , Bordeaux INP, LCPO, UMR 5629, F-33600 Pessac, France.|CNRS, LCPO, UMR 5629, F-33600 Pessac, France.
Gilles
G
Sèbe
UV stability; cellulose nanocrystals; functionalization; polydimethylsiloxane; thermal stability