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Hydrogen-bonds structure in poly(2-hydroxyethyl methacrylate) studied by temperature-dependent infrared spectroscopy
1Department of Engineering Science, Osaka Electro-Communication University Neyagawa, Japan.
Frontiers in Chemistry
|May 3, 2014
Summary
Hydrogen-bonds in poly(2-hydroxyethyl methacrylate) (PHEMA) were studied using infrared spectroscopy. Changes in hydrogen-bonds structure near 80°C influence polymer chain mobility at the glass transition temperature.
Area of Science:
- Polymer Science
- Materials Science
- Spectroscopy
Background:
- Poly(2-hydroxyethyl methacrylate) (PHEMA) is a widely used polymer with applications in biomaterials and hydrogels.
- Understanding the role of hydrogen-bonding in PHEMA's mechanical and thermal properties is crucial for material design.
Purpose of the Study:
- To investigate the structural changes of hydrogen-bonds in PHEMA.
- To correlate these changes with the polymer's glass transition temperature (Tg).
- To elucidate the impact of hydrogen-bond dynamics on main chain mobility.
Main Methods:
- Temperature-dependent infrared (IR) spectroscopy was employed.
- Analysis focused on spectral variations related to OH…OH and C=O…HO hydrogen-bonds.
Main Results:
- Hydrogen-bonds between hydroxyl groups (OH…OH) gradually dissociate with increasing temperature.
- A discontinuous variation in carbonyl bands (C=O) was observed around the Tg (80°C).
- An association of C=O…HO hydrogen-bonds was revealed above the Tg.
Conclusions:
- OH…OH hydrogen-bonds in side chain terminals suppress main chain mobility below Tg.
- Dissociation of OH…OH bonds induces C=O…HO bond association above Tg.
- Changes in hydrogen-bond structure drive main chain mobility at the glass transition temperature.
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