Polymer microspheres with active carboxyl groups: preparation, structure and hydrophilicity
Zhao Dai1, Xiu-Xue Sun, Ji-Mei Zhang
1State Key Laboratory of Hollow Fiber Membrane Materials and Processes, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, 300160 Tianjin, PR China.
Journal of Nanoscience and Nanotechnology
|March 14, 2012
Summary
The study found that increasing acrylic acid in microspheres boosts carboxyl group loading and hydrophilicity. Poly(ethylene glycol dimethacrylate-co-acrylic acid) microspheres showed superior performance compared to poly(divinylbenzene-80-co-acrylic acid) microspheres.
Area of Science:
- Polymer chemistry
- Materials science
- Surface science
Background:
- Microspheres with surface functional groups are crucial for various applications.
- Controlling the density and properties of surface functional groups is essential for optimizing performance.
- Polymer composition significantly influences microsphere characteristics.
Purpose of the Study:
- To quantitatively investigate the effect of acrylic acid (AA) monomer ratio on the surface carboxyl group loading capacity and hydrophilicity of P(EGDMA-co-AA) and P(DVB-co-AA) microspheres.
- To compare the performance of microspheres using different crosslinkers (EGDMA vs. DVB-80) at fixed AA fractions.
Main Methods:
- Distillation-precipitation polymerization technique was employed for microsphere synthesis.
- Titration was used to determine the loading capacity of active carboxyl groups.
- Contact angle measurements were performed to assess particle hydrophilicity.
Main Results:
- Increased acrylic acid (AA) feed ratio led to higher carboxyl group loading capacity and decreased contact angle, indicating enhanced hydrophilicity.
- Hydrophilicity was primarily governed by the AA monomer ratio.
- At a fixed AA fraction, P(EGDMA-co-AA) microspheres exhibited a higher carboxyl group loading capacity and lower contact angle than P(DVB-co-AA) microspheres.
Conclusions:
- The feed ratio of acrylic acid monomer is the dominant factor in determining the hydrophilicity and carboxyl group loading of these microspheres.
- Poly(ethylene glycol dimethacrylate-co-acrylic acid) microspheres demonstrate superior hydrophilic properties and carboxyl group density compared to poly(divinylbenzene-80-co-acrylic acid) microspheres, suggesting their potential for applications requiring high surface functionality and water affinity.
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