Novel bifunctional polymer with reactivity and temperature sensitivity.

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Poly(N-isopropylacrylamide) (PIPAAm) is a temperature-responsive polymer with a lower critical solution temperature (LCST) around 32°C.
• Copolymerization of IPAAm with monomers like acrylic acid (AAc) can alter its properties, often reducing temperature sensitivity.
• There is a need for bifunctional polymers combining reactivity and sensitive temperature response for advanced applications.

Purpose of the Study:

• To synthesize a bifunctional copolymer with both reactive groups and temperature sensitivity.
• To investigate the synthesis and properties of poly(IPAAm-co-CIPAAm) copolymers.
• To compare the temperature-responsive behavior of poly(IPAAm-co-CIPAAm) with poly(IPAAm-co-AAc).

Main Methods:

• Copolymerization of N-isopropylacrylamide (IPAAm) with 2-carboxyisopropylacrylamide (CIPAAm).
• Synthesis of poly(IPAAm-co-AAc) for comparison.
• Measurement of transmittance of polymer aqueous solutions to determine phase transition temperatures (LCST).
• Evaluation of copolymer behavior across different pH conditions.

Main Results:

• The synthesized poly(IPAAm-co-CIPAAm) exhibited a sharp phase transition within a narrow temperature range, similar to IPAAm homopolymer.
• The temperature-responsive behavior of poly(IPAAm-co-CIPAAm) was maintained even at neutral and slightly alkaline pH.
• In contrast, poly(IPAAm-co-AAc) showed reduced and less sensitive temperature-responsive behavior with increasing AAc content.

Conclusions:

• A novel bifunctional polymer, poly(IPAAm-co-CIPAAm), was successfully prepared.
• This copolymer effectively combines reactive functional groups with sensitive temperature-responsive properties.
• The findings suggest that maintaining a homopolymer-like structure is crucial for sensitive temperature response in functionalized copolymers.