Thermogels Based on Block versus Gradient Terpolymers: Differences in the Nano- and Macro-Scale

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Copolymers are versatile materials with tunable properties.
• Understanding the influence of monomer sequence distribution is crucial for designing advanced polymers.
• Oligo-(ethylene glycol) methyl ether methacrylate (A), n-butyl methacrylate (B), and di-(ethylene glycol) methyl ether methacrylate (C) are key monomers for thermoresponsive materials.

Purpose of the Study:

• To investigate the effect of monomer distribution in terpolymers on their properties.
• To synthesize and characterize various linear copolymer architectures, including statistical, gradient, and block structures.
• To explore the thermoresponsive and gelation behavior of these copolymers, with a focus on gradient structures.

Main Methods:

• Group transfer polymerization for synthesizing linear copolymers.
• One-pot synthesis for a forced gradient terpolymer.
• Synchrotron small-angle X-ray scattering (SAXS) for analyzing self-assembled structures.
• Solubility and gelation studies.

Main Results:

• Monomer distribution along the polymer chain critically governs copolymer solubility and gelation.
• ABC block and gradient copolymer structures exhibited superior performance compared to statistical structures.
• Distinct self-assembly and aggregation mechanisms were observed between ABC triblock and gradient terpolymers.
• The gradient terpolymer demonstrated significant thermoresponsive and gelation properties.

Conclusions:

• The arrangement of monomer units is a key factor in determining copolymer behavior.
• Gradient terpolymers offer a promising platform for developing novel materials.
• These findings pave the way for advanced copolymer design with potential biomedical applications.