Structure-Property Relationships in 5-Aminosalicylic Acid-Functionalized Poly(GMA-co-EGDMA) Microspheres: Porosity,...

Area of Science:

• Polymer Chemistry
• Materials Science
• Environmental Science

Background:

• Microspheres offer tunable properties for various applications.
• Functionalization enhances material performance in specific tasks.
• Chromium(VI) is a toxic pollutant requiring effective removal methods.

Purpose of the Study:

• To synthesize and characterize functional poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres.
• To modify these microspheres with 5-aminosalicylic acid (ASA).
• To evaluate the performance of ASA-modified microspheres as sorbents for Cr(VI) ions.

Main Methods:

• Suspension-emulsion polymerization to create poly(GMA-co-EGDMA) microspheres.
• Post-polymerization modification with 5-aminosalicylic acid (ASA).
• Characterization using FTIR, acid number measurements, thermal analysis (TG/DTG, TG-FTIR), and Brunauer-Emmett-Teller (BET) analysis.
• Cr(VI) sorption studies under varying pH conditions.

Main Results:

• Increasing GMA content enhanced epoxy group density but decreased surface area.
• Successful ASA functionalization was confirmed, preserving the mesoporous structure.
• ASA-modified microspheres exhibited improved thermal stability.
• Maximum Cr(VI) removal efficiency was observed under acidic conditions, reaching ~100 mg/g.
• Sorption mechanism involved electrostatic interactions between protonated groups and Cr(VI) ions.

Conclusions:

• ASA-functionalized poly(GMA-co-EGDMA) microspheres offer tunable functionality and porosity.
• These modified microspheres demonstrate enhanced thermal stability.
• The materials are effective and selective sorbents for Cr(VI) removal, particularly in acidic media.
• The study highlights the potential of these materials for environmental remediation.