The Phase Structure and Properties of Polyurethanes Based on Polycaprolactone Block Copolymers Dangling Side-Chain...

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Materials Engineering

Background:

• Polycaprolactone (PCL)-based polyurethanes are crucial in biomedical applications.
• Modification with hydrophilic polyethylene glycol (PEG) enhances their performance.
• Side-chain PEG incorporation influences molecular mobility and phase separation, allowing property tuning.

Purpose of the Study:

• To compare the structural and property effects of side-chain PEG placement in soft versus hard segments of polyurethanes.
• To synthesize and characterize novel PCL-based polyurethanes with tailored properties.

Main Methods:

• Designed and synthesized polycaprolactone copolymer soft segments with side-chain PEG.
• Prepared corresponding polyurethanes using these synthesized soft segments.
• Analyzed the structure-property relationships, focusing on hard segment aggregation and phase separation.

Main Results:

• Side-chain PEG positioned away from urethane bonds in the soft segment minimized interference with hard segment aggregation.
• This resulted in a more continuous hard phase and superior overall polyurethane performance.
• The developed polyurethanes demonstrated both one- and two-way shape memory effects at human body temperature (37 °C).

Conclusions:

• Strategic placement of side-chain PEG in the soft segment significantly enhances PCL-based polyurethane properties.
• These modified polyurethanes exhibit promising shape memory capabilities at physiological temperatures.
• This research broadens the potential applications of PCL-based polyurethanes in the biomedical field.