Controlled Synthesis and Crystallization-Driven Self-Assembly of Poly(ε-caprolactone)-b-polysarcosine Block...

Area of Science:

• Polymer Science and Engineering
• Materials Science
• Biomaterials

Background:

• Poly(ε-caprolactone)-b-polysarcosine (PCL-b-PSar) block copolymers are advanced alternatives to PCL-b-PEO for biomedical applications.
• These copolymers offer enhanced biocompatibility and biodegradability.
• Understanding their self-assembly is crucial for developing novel biomaterials.

Purpose of the Study:

• To synthesize PCL-b-PSar block copolymers with controlled architectures.
• To investigate the crystallization-driven self-assembly (CDSA) of these BCPs in various alcohol solvents.
• To develop strategies for achieving uniform self-assembled nanostructures for biomedical applications.

Main Methods:

• Synthesis of PCL-b-PSar block copolymers with controlled polymerization degrees and low polydispersity.
• Systematic investigation of CDSA in ethanol, n-butanol, and n-hexanol.
• Development and application of a modified two-step self-seeding crystallization method (Tc1 = 33 °C, Tc2 = 8 °C).

Main Results:

• Limited PSar solubility in alcohols led to heterogeneous self-assembly (micelles and lamellae).
• The modified self-seeding method successfully converted micelles into crystals, yielding uniform structures.
• BCP structure and solvent quality significantly influenced self-assembly, forming lamellar crystals, hierarchical structures, or dendritic aggregates.

Conclusions:

• The study elucidated the CDSA mechanism of PCL-b-PSar in alcohol solvents.
• A two-step crystallization strategy enables precise control over self-assembled morphologies.
• These findings facilitate the rational design of PCL-b-PSar-based nanomaterials for targeted biomedical applications.