Polyhedral Oligomeric Silsesquioxane (POSS)-Modified Thermoplastic and Thermosetting Nanocomposites: A Review

2008 ◽  
Vol 16 (8) ◽  
pp. 483-500 ◽  
Author(s):  
Jianqing Zhao ◽  
Yi Fu ◽  
Shumei Liu
Keyword(s):  
Processing Condition ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Physical And Mechanical Properties ◽  
Molecular Geometry ◽  
Surface Hydrophobicity ◽  
Dielectric Constants ◽  
Great Promise ◽  
Wide Range ◽  
Oligomeric Silsesquioxane ◽  
Mechanical Strengths

Polyhedral oligomeric silsesquioxane (POSS) nanoparticles have been successfully incorporated into thermoplastic and thermoset polymers via copolymerization, grafting, blending, surface bonding, or other transformations. A great promise in the development of a wide range of POSS-containing nanocomposites with diversely improved properties has been displayed. Thermal properties, viscoelastic properties, mechanical strengths, dielectric constants, surface hydrophobicity and flame-retardancy of the nanocomposites are easily varied to target properties by adjusting POSS structure, crosslink density, processing condition, etc. Investigations on the effects of POSS molecular geometry, composition, and concentration on physical and mechanical properties of resultant POSS-modified thermoplastic and thermosetting nanocomposites have been carefully reviewed in this article.

scholarly journals Functional Polyimide/Polyhedral Oligomeric Silsesquioxane Nanocomposites

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 26 ◽  
Author(s):  
Mohamed Mohamed ◽  
Shiao Kuo
Keyword(s):  
Mechanical Characteristics ◽  
Chemical Resistance ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Surface Hydrophobicity ◽  
Low Dielectric Constant ◽  
Hybrid Nanocomposite ◽  
Low Dielectric ◽  
Redox Stability ◽  
Oligomeric Silsesquioxane ◽  
Physical Blending

The preparation of hybrid nanocomposite materials derived from polyhedral oligomeric silsesquioxane (POSS) nanoparticles and polyimide (PI) has recently attracted much attention from both academia and industry, because such materials can display low water absorption, high thermal stability, good mechanical characteristics, low dielectric constant, flame retardance, chemical resistance, thermo-redox stability, surface hydrophobicity, and excellent electrical properties. Herein, we discussed the various methods that have been used to insert POSS nanoparticles into PI matrices, through covalent chemical bonding and physical blending, as well as the influence of the POSS units on the physical properties of the PIs.

scholarly journals Polyhedral Oligomeric Silsesquioxane (POSS) Surface Grafting: A Novel Method to Enhance Polylactide Hydrolysis Resistance

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1144 ◽  
Author(s):  
Li ◽  
Colonna ◽  
Fina ◽  
Monticelli
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polymer Surface ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Film Surface ◽  
Surface Hydrophobicity ◽  
Homogeneous Distribution ◽  
Angle Measurements ◽  
The Stability ◽  
Hydrolysis Resistance ◽  
Oligomeric Silsesquioxane

Abstract: This work considers the development of an easy and scalable approach to change the features of poly(l-lactide) (PLLA) films, which is based on the application of a surface treatment with an amino-functionalized polyhedral oligomeric silsesquioxane (POSS). Indeed, the developed approach is based on the potential reactivity of POSS amino group towards the polymer functionalities to produce an aminolysis reaction, which should promote the direct grafting of the silsesquioxane molecules on the polymer surface. Neat and treated films were studied by infrared spectroscopy and X-ray photoelectron spectroscopy, which proved the effectiveness of POSS grafting. Moreover, scanning electron microscopy measurements demonstrated the homogeneous distribution of Si on the film surface treated with the silsesquioxane. The influence of the film treatment on the surface wettability was evidenced by contact angle measurements. These findings demonstrated a relevant enhancement of the surface hydrophobicity, which increase turned out to depend on the conditions applied, as it increased by increasing the reaction temperature and the contact time. Finally, in order to evaluate the stability of neat and of the treated PLLA films the surface morphology of the samples treated with pH 7.4 buffer at 50 °C was studied.

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating 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
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