Highly Homogeneous Polysiloxane Flexible Coating for Low Earth Orbital Spacecraft with Ultraefficient Atomic Oxygen Resistance and Self-Healing Behavior

2019 ◽  
Vol 1 (12) ◽  
pp. 3253-3260 ◽  
Author(s):  
Min Xu ◽  
Yunping Zhao ◽  
Xiaoyu Zhang ◽  
Zhonghua Li ◽  
Lin Zhao ◽  
...  
Keyword(s):  
Atomic Oxygen ◽  
Self Healing ◽  
Orbital Spacecraft ◽  
Flexible Coating

scholarly journals Self-Healing Anti-Atomic-Oxygen Phosphorus-Containing Polyimide Film via Molecular Level Incorporation of Nanocage Trisilanolphenyl POSS: Preparation and Characterization

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1013 ◽  
Author(s):  
Bohan Wu ◽  
Yan Zhang ◽  
Dayong Yang ◽  
Yanbin Yang ◽  
Qiang Yu ◽  
...  
Keyword(s):  
Atomic Oxygen ◽  
Composite Films ◽  
Polymeric Materials ◽  
Polyimide Film ◽  
Low Earth Orbit ◽  
Nanocomposite Films ◽  
Self Healing ◽  
Passivation Layers ◽  
Pyromellitic Anhydride ◽  
Oligomeric Silsesquioxane

Protection of polymeric materials from the atomic oxygen erosion in low-earth orbit spacecrafts has become one of the most important research topics in aerospace science. In the current research, a series of novel organic/inorganic nanocomposite films with excellent atomic oxygen (AO) resistance are prepared from the phosphorous-containing polyimide (FPI) matrix and trisilanolphenyl polyhedral oligomeric silsesquioxane (TSP–POSS) additive. The PI matrix derived from 2,2’-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,5-bis[(4-amino- phenoxy)phenyl]diphenylphosphine oxide (BADPO) itself possesses the self-healing feature in AO environment. Incorporation of TSP–POSS further enhances the AO resistance of the FPI/TSP composite films via a Si–P synergic effect. Meanwhile, the thermal stability of the pristine film is maintained. The FPI-25 composite film with a 25 wt % loading of TSP–POSS in the FPI matrix exhibits an AO erosion yield of 3.1 × 10−26 cm3/atom after an AO attack of 4.0 × 1020 atoms/cm2, which is only 5.8% and 1.0% that of pristine FPI-0 film (6FDA-BADPO) and PI-ref (PMDA-ODA) film derived from 1,2,4,5-pyromellitic anhydride (PMDA) and 4,4’-oxydianline (ODA), respectively. Inert phosphorous and silicon-containing passivation layers are observed at the surface of films during AO exposure.

scholarly journals Atomic Oxygen-Resistant Polyimide Composite Films Containing Nanocaged Polyhedral Oligomeric Silsesquioxane Components in Matrix and Fillers

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 141
Author(s):  
Yan Zhang ◽  
Hao Wu ◽  
Yi-dan Guo ◽  
Yan-bin Yang ◽  
Qiang Yu ◽  
...  
Keyword(s):  
High Temperature ◽  
Atomic Oxygen ◽  
Composite Films ◽  
Linear Thermal Expansion ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Low Earth Orbit ◽  
Aromatic Diamine ◽  
Self Healing ◽  
Passivation Layers ◽  
Oligomeric Silsesquioxane

For the development of spacecraft with long-servicing life in low earth orbit (LEO), high-temperature resistant polymer films with long-term atomic oxygen (AO) resistant features are highly desired. The relatively poor AO resistance of standard polyimide (PI) films greatly limited their applications in LEO spacecraft. In this work, we successfully prepared a series of novel AO resistant PI composite films containing nanocaged polyhedral oligomeric silsesquioxane (POSS) components in both the PI matrix and the fillers. The POSS-containing PI matrix film was prepared from a POSS-substituted aromatic diamine, N-[(heptaisobutyl-POSS)propyl]-3,5-diaminobenzamide (DABA-POSS) and a common aromatic diamine, 4,4′-oxydianline (ODA) and the aromatic dianhydride, pyromellitic dianhydride (PMDA) by a two-step thermal imidization procedure. The POSS-containing filler, trisilanolphenyl POSS (TSP-POSS) was added with the fixed proportion of 20 wt% in the final films. Incorporation of TSP-POSS additive apparently improved the thermal stability, but decreased the high-temperature dimensional stable nature of the PI composite films. The 5% weight loss temperature (T5%) of POSS-PI-20 with 20 wt% of DABA-POSS is 564 °C, and its coefficient of linear thermal expansion (CTE) is 81.0 × 10−6/K. The former is 16 °C lower and the latter was 20.0 × 10−6/K higher than those of the POSS-PI-10 film (T5% = 580 °C, CTE = 61.0 × 10−6/K), respectively. POSS components endowed the PI composite films excellent AO resistance and self-healing characteristics in AO environments. POSS-PI-30 exhibits the lowest AO erosion yield (Es) of 1.64 × 10−26 cm3/atom under AO exposure with a flux of 2.51 × 1021 atoms/cm2, which is more than two orders of magnitude lower than the referenced PI (PMDA-ODA) film. Inert silica or silicate passivation layers were detected on the surface of the PI composite films exposed to AO.

Autonomous self-healing polyisoprene elastomers with high modulus and good toughness based on the synergy of dynamic ionic crosslinks and highly disordered crystals

2020 ◽  
Vol 11 (41) ◽  
pp. 6549-6558
Author(s):  
Yohei Miwa ◽  
Mayu Yamada ◽  
Yu Shinke ◽  
Shoichi Kutsumizu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Self Healing ◽  
High Modulus ◽  
Disordered Crystals ◽  
Ionic Crosslinks

We designed a novel polyisoprene elastomer with high mechanical properties and autonomous self-healing capability at room temperature facilitated by the coexistence of dynamic ionic crosslinks and crystalline components that slowly reassembled.

Congenital self-healing histiocytosis

1982 ◽  
Vol 118 (4) ◽  
pp. 267-272 ◽  
Author(s):  
E. Bonifazi
Keyword(s):  
Self Healing

Self-healing juvenile cutaneous mucinosis

1995 ◽  
Vol 131 (4) ◽  
pp. 459-461 ◽  
Author(s):  
R. Caputo
Keyword(s):  
Self Healing
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