Synthesis of Aromatic Polyhedral Oligomeric SilSesquioxane (POSS) Dianilines for Use in High-Temperature Polyimides

Silicon ◽  
2012 ◽  
Vol 4 (4) ◽  
pp. 267-280 ◽  
Author(s):  
Vandana Vij ◽  
Timothy S. Haddad ◽  
Gregory R. Yandek ◽  
Sean M. Ramirez ◽  
Joseph M. Mabry
Keyword(s):  
High Temperature ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Oligomeric Silsesquioxane

scholarly journals High-temperature molecular screening of hybrid polyOAPS-imide networks based on octa(aminophenyl)silsesquioxane for increased thermomechanical resistance

2021 ◽  
Author(s):  
Sylvie Neyertz ◽  
Saman Salimi ◽  
Farzaneh Radmanesh ◽  
Nieck E. Benes ◽  
David Brown
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Interfacial Polycondensation ◽  
Molecular Screening ◽  
New Family ◽  
Oligomeric Silsesquioxane ◽  
Covalently Bound

A new family of hybrid hyper-cross-linked thin films based on inorganic polyhedral oligomeric silsesquioxane (POSS) cages covalently bound with short organic imides has recently been developed using interfacial polycondensation followed...

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.

scholarly journals Polybenzimidazole and Phosphonic Acid Groups-Functionalized Polyhedral Oligomeric Silsesquioxane Composite Electrolyte for High Temperature Proton Exchange Membrane

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Sung-Kon Kim
Keyword(s):  
High Temperature ◽  
Composite Membrane ◽  
Phosphonic Acid ◽  
Proton Exchange Membrane ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Proton Exchange ◽  
High Yield ◽  
Phosphonic Acid Groups ◽  
Oligomeric Silsesquioxane ◽  
Exchange Membrane

Here, we report composite membrane consisting of poly[2,2′-(m-phenylene)-5,5′-(bibenzimidazole)] (PBI) and polyhedral oligomeric silsesquioxane functionalized with phosphonic acid groups (PO(OH)2-POSS) for high temperature proton exchange membrane. ~7 phosphonic acid groups are incorporated into the phenyl rings of POSS via bromination in a high yield (~93%), followed by substitution of the bromine elements by phosphonate ester groupsviaa Pd(0) catalyzed P–C coupling reaction. Phosphonic acid groups are formed by the hydrolysis of the phosphonate ester groups in hydrobromic acid solution. At a 50 wt% of PA content in the membranes, PBI/PO(OH)2-POSS composite membrane shows larger proton conductivity of 3.2 × 10−3 S cm−1than 2.8 × 10−3 S cm−1of PBI membrane at 150°C and anhydrous conditions, owing to the multiple phosphonic acid groups of PO(OH)2-POSS that can function as proton transport medium at high temperature and low humidity conditions.

Model Polyhedral Oligomeric Silsesquioxane Thin Films for Coating Applications

2002 ◽  
Author(s):  
Brent Viers ◽  
Shawn Phillips ◽  
Timothy Haddad ◽  
Alan Esker ◽  
Joe Polidan
Keyword(s):  
Thin Films ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Oligomeric Silsesquioxane

Polyhedral Oligomeric Silsesquioxane /Platelets Rich Plasma/Gelrite-Based Hydrogel Scaffold for Bone Tissue Engineering

2020 ◽  
Vol 26 (26) ◽  
pp. 3147-3160
Author(s):  
Saeedeh Ahmadipour ◽  
Jaleh Varshosaz ◽  
Batool Hashemibeni ◽  
Leila Safaeian ◽  
Maziar Manshaei
Keyword(s):  
Bone Fractures ◽  
Compressive Strain ◽  
Gelation Time ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Local Drug Delivery ◽  
Gelling Agent ◽  
Control Group ◽  
Hydrogel Scaffold ◽  
Alizarin Red ◽  
Oligomeric Silsesquioxane

Background: Polyhedral oligomeric silsesquioxane (POSS) is a monomer with silicon structure and an internal nanometric cage. Objective: The purpose of this study was to provide an injectable hydrogel that could be easily located in open or closed bone fractures and injuries, and also to reduce the possible risks of infections caused by bone graft either as an allograft or an autograft. Methods: Various formulations of temperature sensitive hydrogels containing hydroxyapatite, Gelrite, POSS and platelets rich plasma (PRP), such as the co-gelling agent and cell growth enhancer, were prepared. The hydrogels were characterized for their injectability, gelation time, phase transition temperature and viscosity. Other physical properties of the optimized formulation including compressive stress, compressive strain and Young’s modulus as mechanical properties, as well as storage and loss modulus, swelling ratio, biodegradation behavior and cell toxicity as rheometrical parameters were studied on human osteoblast MG-63 cells. Alizarin red tests were conducted to study the qualitative and quantitative osteogenic capability of the designed scaffold, and the cell adhesion to the scaffold was visualized by scanning electron microscopy. Results: The results demonstrated that the hydrogel scaffold mechanical force and injectability were 3.34±0.44 Mpa and 12.57 N, respectively. Moreover, the scaffold showed higher calcium granules production in alizarin red staining compared to the control group. The proliferation of the cells in G4.5H1P0.03PRP10 formulation was significantly higher than in other formulations (p<0.05). Conclusion: The optimized Gelrite/Hydroxyapatite/POSS/PRP hydrogel scaffold has useful impacts on osteoblasts activity, and may be beneficial for local drug delivery in complications including a break or bone loss.

scholarly journals Polyhedral oligomeric silsesquioxane (POSS)-modified phenolic resin: Synthesis and anti-oxidation properties

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 316-326
Author(s):  
Bing Wang ◽  
Minxian Shi ◽  
Jie Ding ◽  
Zhixiong Huang
Keyword(s):  
Phenolic Resin ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Synthesis Process ◽  
H Nmr ◽  
Chemical Structures ◽  
Carbon Fiber Fabric ◽  
Oxidation Properties ◽  
Tg And Dtg ◽  
Oligomeric Silsesquioxane ◽  
Fiber Fabric

Abstract In this work, octamercapto polyhedral oligomeric silsesquioxane (POSS-8SH) and octaphenol polyhedral oligomeric silsesquioxane (POSS-8Phenol) were successfully synthetized. POSS-8Phenol was added into the synthesis process of liquid thermoset phenolic resin (PR) to obtain POSS-modified phenolic resin (POSS-PR). Chemical structures of POSS-8SH, POSS-8Phenol, and POSS-PR were confirmed by FTIR and 1H-NMR. TG and DTG analysis under different atmosphere showed that char yield of POSS-PR at 1,000°C increased from 58.6% to 65.2% in N2, which in air increased from 2.3% to 26.9% at 700°C. The maximum pyrolysis temperature in air increased from 543°C to 680°C, which meant better anti-oxidation properties. XRD results confirmed both POSS-8Phenol and POSS-PR-generated crystalline SiO2 in air, which could explain the improvement of anti-oxidation properties. SEM showed that the POSS-PR had phase separation during curing process. Finally, carbon fiber fabric-reinforced POSS-PR (C-POSS-PR) was prepared to verify the anti-oxidation properties of POSS-PR.

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