Amino-POSS Grafted Polyimide-Based Self-Stratifying Composite Coatings for Simultaneously Improved Mechanical and...

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Emerging high-tech industries require advanced composite materials with superior mechanical performance and wear resistance.
• Polyimide (PI) resins are versatile but often need enhanced properties for demanding applications.

Purpose of the Study:

• To fabricate novel organic-inorganic self-stratifying gradient coatings using POSS and PI.
• To investigate the effect of POSS incorporation on the microstructure, chemical characteristics, mechanical properties, and wear resistance of PI-based composites.

Main Methods:

• Chemically bonding octa- and mono-amino polyhedral oligomeric silsesquioxane (POSS) onto a polyimide (PI) resin.
• Fabrication of self-stratifying gradient coatings based on silicon density.
• Microstructural and chemical characterization of POSS-PI composites.
• Evaluation of mechanical properties (tensile strength, nano-indentation hardness) and wear resistance.

Main Results:

• POSS addition significantly increased the thermal stability and mechanical properties of PI composites.
• Tensile strength and nano-indentation hardness of 4 wt.% POSS-PI composites improved by 28.6% and 68.4%, respectively.
• Wear rate of POSS-PI self-stratifying coatings decreased by 78.9% compared to pure PI, attributed to enhanced cross-linking and gradient structure.

Conclusions:

• The developed POSS-PI self-stratifying gradient coatings offer enhanced mechanical properties and wear resistance.
• The gradient structure induced by POSS self-stratification is key to improving material performance.
• These advanced composite coatings show potential for applications in high-tech fields demanding robust materials.