Preparation of Amino-Functionalized Poly(N-isopropylacrylamide)-Based Microgel Particles

Area of Science:

• Polymer Chemistry
• Materials Science
• Biotechnology

Background:

• Cationic microgels are crucial for diagnostics and therapeutics, including transfection and biomolecule encapsulation.
• Direct synthesis of cationic poly(N-isopropylacrylamide) (PNIPAm) microgels often yields low incorporation, poor control, and high polydispersity.

Purpose of the Study:

• To investigate post-polymerization modification of P(NIPAm-co-acrylic acid) microgels.
• To synthesize primary amine-functionalized PNIPAm microgels with controlled amine content.

Main Methods:

• Utilized 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC) to couple diamine to carboxyl groups.
• Controlled EDC excess to vary amine functionalization levels.
• Conducted reactions at room temperature in an aqueous medium.

Main Results:

• Achieved variable amine functionalization, incorporating up to 6-7 mol% amine content.
• Demonstrated a time-efficient and practical synthesis approach.
• Successfully prepared primary amine functionalized PNIPAm microgel particles.

Conclusions:

• Post-polymerization modification provides a viable route to amine-functionalized PNIPAm microgels.
• The EDC-mediated coupling offers control over amine incorporation for tailored applications.
• This method is practical for synthesizing functional microgels for diagnostics and therapeutics.