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Preparation and characterization of nanocomposite polyurethane
Yongchun Chen1, Shuxue Zhou, Haihua Yang
1Department of Materials Science, The Advanced Coatings Research Center of China Educational Ministry, Fudan University, Shanghai 200433, People's Republic of China.
Journal of Colloid and Interface Science
|October 7, 2004
Summary
In situ polymerization created stronger bonds between polyester and silica nanoparticles in polyurethane composites compared to blending. This enhanced bonding improved the thermal properties of the resulting nanosilica-polyurethane materials.
Area of Science:
- Materials Science
- Polymer Chemistry
- Nanotechnology
Background:
- Polyurethane (PU) materials are widely used due to their versatile properties.
- Incorporating nanoparticles like nanosilica can enhance PU performance.
- Understanding the influence of preparation methods on composite structure and properties is crucial.
Purpose of the Study:
- To investigate the preparation of polyurethane/nanosilica composites using in situ polymerization and blending methods.
- To analyze the effects of nanosilica incorporation and preparation techniques on PU properties.
- To characterize the dispersion and interfacial interactions of nanosilica within the PU matrix.
Main Methods:
- Polyurethane/nanosilica composites were synthesized via in situ polymerization and blending.
- Characterization included Fourier Transform Infrared Spectroscopy (FTIR), Dynamical Mechanical Analysis (DMA), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), and contact angle measurements.
- Glass transition temperatures (Tg) were determined.
Main Results:
- In situ polymerization resulted in more chemical bonding between polyester segments and silica nanoparticles compared to blending.
- Nanosilica incorporation increased the glass transition temperatures (Tg) of polyurethanes.
- Preparation methods and nanosilica particle size significantly impacted Tg.
- XPS and contact angle analyses showed nanosilica migration towards surfaces/interfaces, reducing surface free energies.
- AFM confirmed nanosilica presence at interfaces, but not on surfaces.
Conclusions:
- In situ polymerization offers superior interfacial interaction between nanosilica and polyurethane compared to blending.
- Nanosilica addition enhances the thermal stability of polyurethanes, with effects modulated by preparation method and particle size.
- Nanosilica preferentially segregates to interfaces, influencing surface properties and composite morphology.